POLITEXT 78
De King Kong a Einstein La f铆sica en la ciencia ficci贸n
POLITEXT
Manuel Moreno Lupiáñez Jordi José Pont
De King Kong a Einstein La física en la ciencia ficción
EDICIONS UPC
Primera edición: octubre de 1999
Diseño de la cubierta: Manuel Andreu y Jorge Calvet Dibujos: Vicent Ribas © © los autores, 1999 Edicions UPC, 1999 Edicions de la Universitat Politècnica de Catalunya, SL Jordi Girona Salgado 31, 08034 Barcelona Tel. 934 016 883 Fax. 934 015 885 Edicions Virtuals: www.edicionsupc.es e-mail: edupc@sg.upc.es
Producción:
Romanyà-Valls Pl. Verdaguer 1, 08786 Capellades (Barcelona)
Depósito legal: B-31.490-99 ISBN: 84-8301-333-9 Quedan rigurosamente prohibidas, sin la autorización escrita de los titulares del copyright, bajo las sanciones establecidas en las leyes, la reproducción total o parcial de esta obra por cualquier medio o procedimiento, comprendidos la reprografía y el tratamiento informático y la distribución de ejemplares de ella mediante alquiler o préstamo públicos, así como la exportación e importación de ejemplares para su distribución y venta fuera del ámbito de la Unión Europea.
V < A tZ %s8 t {Bt js R} st9s I JZ RZ 8$j t$B j } ? B-$8B R s 8 `B JZ j tZ R B O s $ p 88s }B JZ Y 8BR 8st t$IB R$ 8} Rs R} st9s k t R BR $ 8}BR I $I sj R } I$IBR Y 8BR ` {$IB j I {YB s js Z B}? s
V jBR {BR I j }sRsIB s }sR$Bt R I Rs sIsR {B8B Y$ jB RBA PZ B V _$js }B YsA BRsIB BAs j Zt $ 8}B } {$BRB JZ j } t { s }B jj s Zts tZ %s 8Z R s O sj\js JZ R ? I j 8$js B I js %$Is
V 8BIB I } R t s{$? Bt }B B s }s I j BIB $tt { Rs $s
V } $t{$}$BR I jBR sK tBR R t s Z%B {$ B {B }B}Zjs Zt j$A B JZ tBR sj sAs RBA 7 s sAs I I j tB s8 ${stB Vj%$t qB/ JZ$ t t I${Ys BA s 4 -$BtsAs RBA js % jB{$IsI I {s8A$B t Zts {Zj Z s {B8B js tZ R s IB8$tsIs }B jBR P { BR I js {$ t{$s k js {tBjB ? s k RZ -{ }{$Btsj {s}s{$IsI stRPB 8sIB s Ns $I s { t sj I j j$A B I qB/ }Z I -}Bt R I PB 8s {sR$ $t Z$ $%s k {Bt Zt R t{$jjB ` 8}jBU tZ R BR st }sRsIBR ts{$ Bt k s} tI$ Bt s %$%$ t Zt 8ZtIB JZ t stI R j? t sR R Z$ ? s R$ tIB j 8$R8B t B tB IBtI s{sAs ? st RZR I? sR et sJZ j t Bt{ R tB s t { Rs $B sIs} s R s Zt 8ZtIB {s8A$st ks JZ jBR {s8A$BR $t %$ sAj R k R$ 8} } R t R R } BIZ{? st s Zt $ 8B jB RZh{$ t 8 t j t B {B8B }s s tB sj s R$ t$h{s $%s8 t jBR 8BIBR PZtIs8 t sj R I {B8}B s8$ t B } RBtsj IZ st js %$Is I Zt R YZ8stB _ B s tBRB BR }B RZ B }B I R s{$s sj tBR R ? s ks I ht$ $%s8 t % IsIs js jj sIs } 8s Z s I j PZ Z B ej RYB{, I j PZ Z B Ps8$j$s {B8BI$IsI
et jsR Z ?j $8sR I? {sIsR j $ 8B I {s8A$B R Ys Y {YB st s{ j sIB JZ YBk RsA 8BR ks JZ j 8ZtIB t JZ s} tI 8BR s %$%$ k js{$Bts tBR tB R ? s j 8$R8B IBtI %$%$ 8BR js 8skB }s I tZ R sR %$IsR ej {s8A$B } R$I tZ R s {$%$j$9s{$? Bt I Zts PB 8s BAR R$%s {B8B tB YsA? s sP { sIB st R s tZ R BR st }sRsIBR eR s8BR BAj$ sIBR s {Bt%$%$ {Bt j PZ Z B k jBR {s8A$BR JZ s}B s O Rs % jB{$IsI s{ j sIs I {s8A$B } B{ I R$t IZIs sj Zts I jBR P { BR JZ js {$ t{$s 8BI ts k js {tBjB ? s s%st9sIs ` { t {B $I$sts8 t RBA tZ R s 8st s I %$%$ eR stIB ks } ? B-$8B s jBR {$t{Z t s sK tBR JZ$ t R{ $A k jsR } RBtsR I js t s RZ % 9 jsR JZ {BtPB 8st jsR R$ Z$ t R t s{$Bt R D Y 8BR 8$R8s t s{$? Bt wk s8A$? %$%$IB tZ R s $tPst{$s k sIBj R{ t{$s R$t st }s I js {tBjB ? s JZ YBk R ? s } R t t tZ R sR %$IsR I PB 8s $t{Z R $BtsAj U js j %$R$? Bt jBR B I tsIB R yt t jsR {B sP? sR js RBtst{$s 8s t? ${s js 8${ B{$ Z ? s jBR tZ %BR 8s $sj R js $t t$ ? s t? ${s k Zt js Z? R$8B {? s tBR Yst BAj$ sIB s sIs} s tBR s 8s {YsR PB 9sIsR s Zt } R t JZ js {tB{$ t{$s sj s I? s s I? s _ B t tI j {s8A$st } R t I tZ R s s{ Zsj$IsI tB R s s P? s{$j _B s9Bt R BA%$sR I j t Zs` {B8}j `$IsI I$h{Zj sI k js $t %$ sAj k R$ 8} { {$ t R} {$sj$9s{$? Bt js {B8} tR$? Bt I js {tB{$ t{$s k RZ % IsI B sj{st{ Yst JZ IsIB I 8sR$sIB sj `sIBR I jsR }BR$A$j$IsI R sj R I js 8skB ? s I js RB{$ IsI 7sA 8BR ks JZ t js $tPst{$s k js sIBj R{ t{$s tBR R $8} R{$tI$Aj tB R? BjB s} tI R$tB k RB R jB 8? sR $8}B st WZ R B PZ Z B {B8B R R YZ8stBR R {Bth Z s ks I RI js t { R$IsI $8} $BRs I sIJZ$ $ R$ 8} tZ %BR {Bt{ } BR k s} tI s 8st `s tZ %BR s Ps{ BR {tBj? B ${BR s} tI s s} tI
_B RB Zt j$A B JZ t j PBtIB s $ tI s js $t %$ sAj s s I js I$%Zj s{$? Bt {$ t ? h{s {B8B j JZ Yst R{ $ B jBR IB{ B R FB I$ FBR? k st j B tB wB st j B tB k FB I$ FBR? JZ st B 8Bt s 8Bt s st BD R I j BIB $8} R{$tI$Aj 7Z s8 tB $t Rst sAs`B tBR s{ {s s jBR {Bt{ } BR I js P? R${s I PB 8s - 8sIs8 t R t{$jjs {B8} tR$Aj k jB 8? sR $8}B st 8Zk P? s{$j8 t {B IsAj * RI Ys{ sK tBR % t B } B{js8stIB js t { R$IsI I Zts I$%Zj s{$? Bt {$ t ? h{s sj k RBA BIB s8 ts k I$% $Is O R j$A B R s8 tB k I$% $IB O R sR {s s{ ? R ${sR tB RBt Zt %sjB 8 tB t jBR s s sIBR I? sR I tZ R B } R t O RB R sR? }B JZ FB I$ k st j tBR -}j${st jBR {Bt{ } BR 8? sR $8}B st R I js P? R${s Z $j$9stIB Zt % Y? {ZjB 8s s%$jjBRBU js {$ t{$s h{{$? Bt ]B8B BIBR RsA t js {$ t{$s h{{$? Bt R R t{$sj8 t Zt ? t B ts s $%B } B}$B k {s s{ ? R ${B I tZ R B R$ jB JZ t js %$ `s PB 8Zjs{$? Bt I j IB{ B yRss{ VR$8B% $t t s stsj$9s js R}Z R s YZ8sts s jBR {s8A$BR t j t$% j I js {$ t{$s k js {tBjB ? s
et {$ s PB 8s jBR j { B R I {$ t{$s h{{$? Bt R } }s st I PB 8s s8 ts }s s %$%$ t j PZ Z B {s8A$st JZ tBR s Zs Is }s s {B8} tI jsR sj ts $%sR JZ js {$ t{$s k js {tBjB ? s tBR I }s st ks k 8? sR $8}B st s? Zt JZ tBR I }s s ? st t Zt PZ Z B sj % 9 { {stB z s8BR Zt ` 8}jB %$I t B8sIB R s % 9 I j {s8}B I js $t t$ ? s t? ${s ]ZstIB t P A B I d R {B Bt? B {Bt ? -$ B j BA` $%B I {jBts Zts B% `s k BIB j 8ZtIB 8} 9? B s YsAjs I *Bjjk I js }BR$Aj {jBts{$? Bt I BIB $}B I 8s8? P BR k t {Bt{ B I js }BR$Aj {jBts{$? Bt I R R YZ8stBR j I As sj{st9? B s js 8skB ? s NBR $tIZIsAj R } BAj 8sR ? ${BR }R${Bj? B ${BR k I BIB $}B JZ }BI ? s {B8}B s js {jBts{$? Bt I R R YZ8stBR I$ Bt jZ s s Zts s8}j$s %s $ IsI I I$R{Z RBR k 8st$P R s{$Bt R * RI j RZ8B }Bt ? h{ I js y j R$s ]s ? Bj${s s {B8$R$Bt R I -} BR I js =We7]! BIB j 8ZtIB R 8st$P R ? B RBA jB JZ t sJZ j 8B8 t B R } R t sAs {B8B Zts st tB% IsI }s s {sR$ BIBR ej R h s jBR j { B R I {$ t{$s h{{$? Bt JZ$ t R Z$sIBR }B js {s}s{$IsI R} {Zjs $%s I RZR 8 `B R sZ B R R YsA? st Ps8$j$s $9sIB ks {Bt jBR }BR$Aj R P { BR k {BtR {Z t{$sR I js {jBts{$? Bt sj ZtsR I {sIsR st R JZ jBR I 8? sR * RI >d n1H I V <Z-j k sj sAZtIst s s8$ t B I j 8s t js {$ t{$s h{{$? Bt I jBR sK tBR R R t s k R t s YsR s jj s s BA sR {sR$ I ht$ $%sR {B8B >d MxH I ] F ]Y kY jBR j { B R I {$ t{$s h{{$? Bt tBR YsA? s8BR s{BR Z8A sIB s } tRs t Rs }BR$A$j$IsIU Zt I? s YsA ? s {jBt R I R R YZ8stBR VI 8? sR I js I$% R$? Bt I Zts j { Z s $t j$ t t? s8BR RBA jBR I 8? sR sj 8 tBR Rs B s % t s`s sIs} s $%s WB R }B{s {BRs t jBR $ 8}BR I {s8A$B s{ j sIB JZ {B t {sR$ ej 8ZtIB P j$9 ]k t
I j $ stIB
eRs R js PZt{$? Bt {s s{ ? R ${s I js AZ ts {$ t{$s h{{$? BtU R $8Zjs js 4 -$? Bt RBA jsR {BtR {Z t{$sR RB{$sj R k I BIB $}B JZ {B8}B s ? st $tI P { $Aj 8 t jsR tZ %sR {tBjB ? sR O Rs PZt{$? Bt R js JZ Yst {B $IB {Bt A $jjst 9 k s8 t$IsI FB I$ FBR? k st j B tB t R j$A B Zt j$A B I I$%Zj s{$? Bt {$ t ? h{s I js P? R${s AsRsIB t js {$ t{$s h{{$? Bt *BR sR} { BR JZ t -{ }{$Btsj sh 8s{$? Bt R$t? ${s tBR B s t {Bt ? -$ B s R {j? sR${B R$ 8} st I$P? {$j k } BAj 8? s ${B $tR Z$
Ns {$ t{$s h{{$? Bt R 8Zk sI {ZsIs }s s jjB _BR IBR {s s{ ? R ${sR } B}$sR JZ js Ys{ t 8Zk R} {$sj _B Zts }s js {$ t{$s h{{$? Bt R Zts ts s $%s JZ tBR } R t s R} {Zjs{$Bt R s $ R sIsR k 8Zk s 8 tZIB P st{s8 t $t t{$BtsIsR JZ tBR Ys{ t 8 I$ s RBA tZ R B 8ZtIB k tZ R s B st$9s{$? Bt RB{$sj B RBA jBR P { BR k jsR {BtR {Z t{$sR I js {$ t{$s k
js {tBjB ? s t jsR RB{$ IsI R JZ jsR Z $j$9st
7 s s sJZ ? I Zts % $ t 4 -$%s I
js {$ t{$s h{{$? Bt JZ s 8 tZIB Ys R %$IB }s s {s s{ $9s s js {$ t{$s h{{$? Bt R{ $ s {B8B Zts % IsI s j$ s Z s I $I sR =ts j$ s Z s JZ Ys Z $j$9sIB R} {Zjs{$Bt R $t j$ t R
RZ $IsR t BIBR jBR s ?8A$ BR k 8Zk t }s ${Zjs t js P? R${s k RZR 8? Zj $}j R s}j${s{$Bt R
_ B }B B s }s js {$ t{$s h{{$? Bt BP { ZtsR }BR$A$j$IsI R I 8s s%$jjs k I sI8$ s{$? Bt {sR$ $ts B sAj R NBR tZ %BR 8ZtIBR k R R jsR tZ %sR {Zj Z sR k {$%$j$9s{$Bt R jsR tZ %sR }BR$T A$j$IsI R I js {$ t{$s k I js {tBjB ? s tBR sA t jBR B`BR I js 8 t s Zt tZ %B Zt$% RB JZ {Bt 8}js8BR 8s s%$jjsIBR k RB } tI$IBR sI t ? stIBtBR t tZ %BR 8ZtIBR I }BR$A$j$IsI R eRB R jB JZ } 8$ JZ jBR R} {$sj$R sR YsAj t I Zt $8}B st R t $IB I jB 8s s%$j jBRB {B8B I ZtB I jBR j 8 t BR 8? sR {s s{ ? R ${BR I js {$ t{$s h{{$? Bt 7Bt } {$Rs8 t RsR R} {Zjs{$Bt R k RsR 8s s%$jjsR I js {$ t{$s h{{$? Bt jsR JZ s s t {B8B tB }BI? s R 8 tBR s jBR `? B% t R JZ R $t Rst P? s{$j8 t }B RZ 8? s ${s k {Bt t$IB JZ Ysjjst t RZR {Bt s{ BR {Bt js {$ t{$s h{{$? Bt 8B $%B I I$% R$? Bt } B s8A$? t I 4 -$? Bt B $ $tsj k } B8 IB s
]Bt R sR R$8}j R P t{$sR R P? s{$j {B8} tI JZ {BtR$I s js {$ t{$s h{{$? Bt {B8B Zt 8s $sj B % Y? {ZjB R} {$sj8 t sI {ZsIB t j s ?8A$ B I jB IB{ t s $t %$ sAj VR? jB
} {$A$ Bt Ys{ ks ZtBR sK tBR sj ZtBR } BP RB R }s ${Zjs 8 t s{ $%BR } t {$ t R sj 8ZtIB st jBRs`? Bt O sR YsA R$IB Zt ? t B $ tB sIB $t{jZRB I R} {$sIB }B j 8ZtIB s{sI? 8${B js {$ t{$s h{{$? Bt Ys jB sIB ks }B RZR } B}$BR 8? $ BR jj s s PB 8s }s I jBR {Z ? {ZjBR I jsR Y$ YTR{YBBjR k Zt$% R$IsI R st jBRs`BtsR VZtJZ t Zt } $8 8B8 t B js {$ t{$s h{{$? Bt R {Bt%$ $? B t j 8 t B I R s{sIB t js tR K tst9s I js j$ s Z s k js j t Zs $t j Rs s8A$? t Ys R$IB Z $j$9sIs js{$Bt? stIBjs {Bt j $8}s{ B RB{$sj I jsR I$% RsR {tBjB ? sR k {B8B s} B-$8s{$? Bt IZ{s $%s s sJZ jjB JZ Vj%$t qB/ %$tB t I tB8$ts j RYB{, I j PZ Z B
WB R ? R j jZ s }s s I sjjs js Y$R B $s I j ZRB IB{ t I js {$ t{$s h{{$? Bt } B R ? {B8 t s ? Bt I eR ZI$BR RBA js { s{$? Bt t d ( I js 7{$ t{ 3${ $Bt i R s {Y VRRB{$s $Bt wVRB{$s{$? js ]$ t{$s 3${{$? Bt 73iVD 3B 8sIs YBk t I? s }B {sR$ 8 I$B 8$jjs I } BP RB R t BIB j 8ZtIB jBR BA` $%BR I js 73iV $t{jZk tU " j R ZI$B I js {$ t{$s h{{$? Bt k js Pst sR? s
8 `B s js tR K tst9s t j sZjs %sjZs jBR tZ %BR j$A BR k jBR tZ %BR 8? BIBR k 8s $sj R I tR K tst9s" 7 s s %$I t 8 t I Z $j$9s js $tI$R{Z $Aj s s{{$? Bt JZ jBR `? B% t R }Z I t R t $ }B js 8? s ${s I js {$ t{$s h{{$? Bt }s s } B8B% RZ ZRB t jsR sZjsR ej RZj sIB I js s{ $%$IsI I js 73iV k B sR RB{$ IsI R }s {$IsR Ys R$IB Zt { {$ t {Bt`Zt B I s ? {ZjBR k j$A BR I {s ? s{ s{sI? 8${B $t{jZRB js s}s ${$? Bt I %$R sR Zt$% R$ s $sR R} {$sj$9sIsR q sR js }$Bt s e- s}Bjs $Bt { sIs t d x }B qYB8sR ]js RBt k I$ sIs R % { R sj sK tB }B js =t$% R$IsI I j eR sIB I t t !Y$B {sA {$ s 3BZtIs $Bt $t${$sIs }B sj{Bj8 eIbs IR t d 1 t j _Bj$ ? {t${B I j WB R I NBtI R k 7{$ t{ 3${ $Bt 7 ZI$ R PZtIsIs t d n }B *s ,B 7Z%$t k i * Zjj t t j * }s s8 t B I yt j? R I js =t$% R$IsI ]Bt{B I$s t Bt ? sj s8AsR s8A$? t I } $BI${$IsI {Zs $8 R sj Ns $I s { t sj I R sR s}s ${$Bt R {B ? s t Zt } $8 8B8 t B js {Bt% t$ t{$s I Z $j$9s }s s js tR K tst9s I js j t Zs k j$ s Z s $t j RsR BA sR {Zks 8? s ${s }Z Is R I 8skB $t ? R }s s jBR sjZ8tBR JZ jBR - BR Z $j$9sIBR sI${$Btsj8 t t R BR 8 t R R i RZj sAs 8Z{YB 8? sR P? s{$j JZ jBR `? B% t R I YBk R $t Rs st st R }B BA sR {B8B Ns 8stB $9JZ$ Is I js BR{Z $IsI >d E H I = RZjs N pZ$t JZ }B }Bt Zt ` 8}jB }B ej }s s? RB } I$IB >dEE H I
FBYt $j Bt I j {Zsj jBR `? B% t R I j R$ jB R ? st }B jB 8 tBR Zt st B I$R st R _ B s8A$? t {sA j ZRB I js {$ t{$s h{{$? Bt }s s 8Z{YBR B BR {B8 $IBR IB{ t R {B8B 8Z R s js R$8}j tZ8 s{$? Bt I sj ZtBR {Z RBR st jBRs`Bt R {$ t RU ]$ t{$s h{{$? Bt k js tR K tst9s I jsR {$ t{$sR ]$ t{$s h{{$? Bt t Zt {Z RB I "ytPB 8? s ${s k 7B{$ IsI" ]$ t{$s h{{$? Bt RB{$sj Ns tR K tst9s I js {$ t{$s h{{$? Bt {Bt {Bt t$IB }Bj? ${B { VZtJZ s sj ZtBR j { B R R ZRB IB{ t I js {$ t{$s h{{$? Bt t j 8ZtIB st jBRs`? Bt }Z Is }s { j R I 8sR$sIB j `stB ks Ys{ sK tBR JZ Ys jj sIB s tZ R B }s? R k R }BR$Aj R K ts s8A$? t sj ZtsR $t${$s $%sR {Z RBR k }ZAj${s{$Bt R JZ Z $j$9st js {$ t{$s h{{$? Bt {B8B 8s $sj IZ{s $%B }s s js tR K tst9s I jsR {$ t{$sR ]Bt%$ t sI% $ JZ tB R t { Rs $B JZ js {$ t{$s h{{$? Bt s k ts s $%s t I ht$ $%s R s -s{ s k {B { s t RZ ZRB I js {$ t{$s k I js ? {t${s V % { R AsR s Z $j$9s j %$I t s s{ $%B JZ jBR `? B% t R R$ t t }B js 8? s ${s I js {$ t{$s h{{$? Bt }s s }BI 4 -$Bts RBA Y {YBR {$ t ? h{BR k - s tR K tst9sR I jBR 8$R8BR FB I$ FBR? k st j B tB {B8B AZ tBR } BP RB R RBt {BtRZ8sIBR -} BR t R s I Rs{s tR K tst9sR $t{jZRB I jBR 8Z{YBR k st sR % { R I$R}s s sIBR B R JZ RZ t t 8Z{YsR } j? {ZjsR I {$ t{$s h{{$? Bt _ BP RB R I j * }s s8 t B I 3? R${s yt t$ ? s WZ{j s I js =t$% R$ s _Bj$ r {t${s I k st j B tB $ t t ks %s $BR sK tBR I -} $ t{$s {Bt RZ {Z RB ]s sjZtks w=_]D FB I$ FBR? RBA 3? R${s $ {$r t{$sTh{{$? B $8}s $IB I RI j {Z RB d nTd ; =t {Z RB P st{s8 t }B}Zjs B 8ZjsR D JZ JZ Ys t sIB ks Zt $t Rst ? R$8B j$A B I - B wZtB I RBR j$A BR {Bt P? jj %s j 8$R8B ? ZjB I j {Z RB weI${$Bt R =_] d ;D < t$IB js RZ I R R $ B } $%$j $sIB I {? B8B j st $t ? R I FB I$ k st j }B js P? R${s js I$%Zj s{$? Bt {$ t ? h{s k js {$ t{$s h{{$? Bt R 8s $sj$9s Bt } $8 B t sj ZtsR {BtP T Z k I R}Z? R I A$IB s 8$ } RsIs $tR$R t{$s t s { jBtsD t{$sR w t z$jstB%s $ js p j ? ? sR s I jj s Bt jBR {Z RBR Zt$% R$ s $BR I 3? R${s $ {$r t{$sTh{{$? B wYsR s YBk ZtB I jBR I 8skB ? -$ B I 8s ? {Zjs t j ]s8}ZR WB I s { jBts I js =_]D k }BR $B 8 t B sR s{ $%$IsI R I I$%Zj s{$? Bt JZ jBR 8$R8BR sZ B R {B8 t st t RZ } R t s{$? Bt I R s tZ %s -}BR${$? Bt I Zt 8s JZ IB8$tst k JZ -}Bt t {Bt Zts 8s R ? s $t$ ZsjsAj q sR j j$A B I - B I j {Z RB ks {$ sIB }s {? s {Bt% t$ t JZ$ s jsR P? B 8ZjsR k Ys{ s{{ R$Aj j j$A B k ? RZ $JZ 9s I$I? s{ ${s s B B $}B I j { B R eR R j BA` $%B I j } R t j$A B JZ B I ts s{ Zsj$9s {B8}j s k 8 `B s {js s8 t js % R$? Bt st $B O t 8$ B}$t$? Bt j BA` $%B R Ys sj{st9sIB {Bt { { R 7 sh 8s JZ js t%$I$s R j 8? sR R}sK tBj I jBR } {sIBR {s}$ sj R k sj % 9 tB R s B{$BRB {BtB{ JZ } RBtsj8 t R$ t B js 8? sR IB sIs I jsR t%$I$sR R} { B s R sAs`B I FB I$ FBR? k st j B tB ZR s ? s YsA R$IB kB JZ$ t jB YZA$ R jj %sIB s {sAB eR Bk R Z B I JZ tB YsA ? s }BI$IB Ys{ jB 8 `B +Z ZR I R jB I$RP Z t
s { jBts B{ ZA I d M
$JZ j s { j? B
? ytI${
dn
? ytI${
_ ? BjB B d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs d d d 1 d n d ; V t{$? BtU {Z$IsIB {Bt jsR YB 8$ sR Ns P? R${s I pZjj$% U $ st R k tstBR z $t 8$j j ZsR I %$s` RZA8${ BR{? B}${B ? sJZ$tsR k s $jZ $BR I ? R k B BR 8ZtIBR
dx
1d 1 ;d xd
1 =ts BI$R s t j R}s{$BU I j et } $R sj <sj{? Bt $j ts $B 1 d 1 1 1 n 1 ; 1 x 1 E ]$t{B {Zs B R IBR ZtB gy t${$? Bt * js q$ s s g s RBB8 "F P B B s ` P B`BU t }BR${$? Bt" s R {$j? tI ${BR RP sR I *kRBt k R s{$Bt R B A$ sj R 7 AZR{s AB Bt R }s s sR{ tRB R}s{$sj 5iskBR2 giskBR 7$tPBt? s }s s B s Z s I jsR sjs-$sR d n ME 1 d(n d(x
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B n d n 1 n n n ; n x 3jsRY j j? s8}s B YZ8stB * j YB8A 8Z {$? js B sj YB8A s sK ts 7Z} 8st Zt RZ} Y? B 8BI? j${B WZ %BR YB8A R }s s j 8sK tsts et AZR{s I j YB8A $t%$R$Aj dd dn( d;n dx dEE
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2 ; d ; 1 ; n ; ; 3st sR? sR j? { ${sR k 8s t? ${sR ej 8BtR ZB I 3 st, tR $t k js j { BA$BjB ? s e8ZjstIB s jBR I$BR RU { sR }s s js $t8B sj$IsI NBR w}R ZIBD}BI R I js 8 t dM( dM1 d n 1(
d;
* $t Bt s e$tR $t
x N k tIsR I Zt }jst s jjs8sIB q$ s x d x 1 x n x ; _${Tt${ t j { t B I js q$ s <BjB{sZR BRU I j 8ZtIB I sI s- sj $t%$ tB qB tsIBR %Bj{st R k B sR {s ? sR BP R * j 8s $jjB I NZ{$P sj 8s $jjB I *$BR tZ{j s 11; 1nd 1;n 1x;
E pZ? s }s s %$s` BR I j $ 8}B E d E 1 E n E ; E x E E _ ? B-$8s R s{$? BtU R$ jB ]B R}BtI t{$s {Bt B sR j? t sR I j $ 8}B 5* t B I {$ t sK tBR BIBR {sj%BR2 q st{ R Y$}t? B ${BR k { $B t$s W$ BR }R${? B}s sR {sZRsj$IsI k }s sIB`sR Ns P? R${s I jBR %$s` R t j $ 8}B Ws% R t s{$Btsj R $8} $BR sj? s{ ${BR V Z` BR I ZRstB k B BR j sIBR I js js $%$IsI t sj 1EM 1 1Md 1 1 n( nd; n1n nn
? ytI${ sjPsA? ${B V sI {$8$ t BR
_ ? BjB B Ns {$ t{$s -}j${s j Zt$% RB js }R${BjB ? s -}j${s jBR R R } B Ysk JZ RsA I P tI R tB { I tB I `s R s st{s jsR Z ?j $8sR 8$ s`sR I $jZR$? Bt
iB8s$t ps k NBR }? s`s BR %st s 8B $ sj _ ? Z V % { R YsR s js P? R${s I `s }sRB s js j? B ${s
7}B{, t 7 s q ,U sJZ j }s? R I R{BtB{$IB Ns {$ t{$s h{{$? Bt R Ys $ $IB t Zts }BI BRs Y s8$ t s I s} tI$9s` k s} B-$8s{$? Bt sj 8ZtIB I js {$ t{$s ]B8B RBR $ t j P? R${B V8sI Z Bt B B "js h{{$? Bt JZ tBR R$ % I t t$8$ t B k tBR skZIs s RBK ts R $8Zjs js {Z $BR$IsI k js $8s $ts{$? Bt WBR 8Z % s js $tIs s{$? Bt I jB I R{BtB{$IB k s js A? ZRJZ Is I -}j${s{$Bt R jsR 8$R8sR s{ $ ZI R JZ R t{Z t st t j B $ t I js {$ t{$s" WB RZj s RB } tI t }B jB st B JZ {$ t ? h{BR {B8B 7 }Y t G <sb,$t ]s j 7s st 7 % t G $tA 7Y jIBt N pjsRYBb B Z sk p jjT stt wjBR R Z ?j $8BR jsZ sIBR {Bt j } 8$B WBA j I P? R${sD Yskst {BtB{$IB sA$ s8 t RZ I ZIs {Bt js {$ t{$s h{{$? Bt {B8B st Rsjs s RZR A $jjst R sk { B $sR t j 8ZtIB I js P? R${s Vh 8s 7 }Y t G <sb,$t U "Ns {$ t{$s h{{$? Bt {B8B js JZ 8Z R s 7 s q , tB {BtR $ Zk Zt R$8}j }sRs $ 8}B R$ % sR$8$R8B s Zt R $B } B}? BR$ BU -}stI$ js $8s $ts{$? Bt YZ8sts > H NB JZ YBk R h{{$? Bt R {Bt%$ s 8 tZIB t h 8 sj$IsI {$ t ? h{s 8sK tsts ]Bthts tZ R s s t{$? Bt s 8s $sR R R R ? s j$8$ s j R}? $ Z YZ8stB" ej 8$R8B $t ? R k s s{ $%B JZ tB R{s}s s st }s I js RB{$ IsI Os I RI jBR sK tBR R R t s sj ZtsR Zt$% R$IsI R tB s8 ${stsR Yst % t$IB ZRstIB j -T sB I$ts $B }B t{$sj I js {$ t{$s h{{$? Bt t js tR K tst9s I I$% RsR I$R{$}j$tsR I RI js RB{$BjB ? s s js A$BjB ? s Ys{$ tIB R{sjs t j 8ZtIB I js P? R${s i {B $ tIB j R $ B I R sR } $8 sR -} $ t{$sR Y 8BR % t$IB sj$9stIB I$% RsR s{ $%$IsI R I s{ {s8$ t B sj 8ZtIB I js P? R${s I js 8stB I js h{{$? Bt 7 8$ts $BR {Z RBR }s s } BP RB R k R ZI$st R R${s k {$ t{$s h{{$? Bt Zts sR$ ts Z s I tR K tst9s R {ZtIs $s {Z RBR Zt$% R$ s $BR w{B8B 3? I j$A j {{$? Bt $8}s $Is t js =t$% R$ s _Bj$ r {t${s I ]s sjZtks w=_]D I RI j {Z RB s{sI? 8${B d nTd ;D {BtP t{$sR }s s R} {$sj$R sR t P? R${s $t{jZRB R 8$ts $BR t jsR VZjsR
I - tR$? Bt Zt$% R$ s $s }s s js { s IsI ]BtR $ Zk t t R? 8$R8sR j h j 4 `B I Zts $t${$s $%s JZ sR{$ tI jBR R ${ BR j? 8$ R s{sI? 8${BR k JZ I PB 8s h{$ t } t s t jBR 8? sR I$% RBR R s8 t BR RB{$sj R =t s8}j$B sAst${B I {Bt - BR $t R R JZ 8Z R s jBR P Z BR I Zts s}Z R s 8Zk t sIB s *${YsR -} $ t{$sR Yst } 8$ $IB {BtR s s {? B8B js B ? s P? R${s RZR j k R k } $t{$}$BR }Z I t s 8 tZIB R $t BIZ{$IBR I PB 8s 8? sR RZ R $%s }B 8 I$B I js {$ t{$s h{{$? Bt ej s s{ $%B I R } B{ I$8$ t B R JZ R$ % I R ? 8ZjB }s s j s} tI$9s` k j j { B R R$ t 8? sR { {s I Zts I$R{$}j$ts sI${$Btsj8 t {B8}j `s {B8B js P? R${s O tB R? BjB jB s{ {s sj 8ZtIB s JZ? 8${s I js P? R${s R$tB JZ sA Zts %? s I s{{ RB s B sR s8sR I js {$ t{$s wA$BjB ? RB{$BjB ? s D ej st? sj$R$R I js P? R${s $tY t s js {$ t{$s h{{$? Bt } B}B {$Bts j 8 t BR I I$R{ZR$? Bt k PB8 t s Zt RsjZIsAj R}? $ Z { ? ${B k R{? } ${B st t { Rs $B t tZ R BR I? sR ]B8B R{ $A js } Is B s FZsts 7st{YBU " j } BAj 8s } $t{$}sj I js tR K tst9s tB sI${s t j s{{ RB s js $tPB 8s{$? Bt R$tB t js t { R$IsI I {Bt s {Bt { $ $BR I R j {{$? Bt {B8} tR$? Bt k stRP t{$s }B }s I j R ZI$st k I j } B}$B } BP RB 7sA R{B RsA Is R t $IB s js $tPB 8s{$? Bt k RsA Z $j$9s js }s s }BI RBj% } BAj 8sR t{s s tZ %sR R$ Zs{$Bt R k {Bt $tZs s} tI$ tIB RBt jsR {Z R $Bt R PZtIs8 t sj R I js tR K tst9s k j s} tI$9s` s{ Zsj R" qs8A$? t skZIs s $t% $ s{ $ ZI R t s $%sR w$t{jZRB YBR $j RD P t s js {$ t{$s k s I$R $t Z$ js {$ t{$s sj I js }R ZIB{$ t{$s Zts tP 8 IsI PZ 8 t s s$ sIs t js RB{$ IsI qBIBR RBR j 8 t BR R t{Z t st t 8skB B 8 tB sIB {B $IBR t R s BA s@ k {BtPB 8st jBR s8A${$BRBR BA` $%BR JZ } R Z$8BR ej } R t - B sAB Is sj ZtBR I jBR stI R RZ K tBR I js {$ t{$s h{{$? BtU js $t8B sj$IsI js $t%$R$A$j$IsI B j %$s` }B j $ 8}B FZt B s js %$R$? Bt JZ 8sts I jsR }? s $tsR B $8? s t R I js h{{$? Bt R I$R{Z js %$sA$j$IsI I jsR $I sR t ? 8$tBR P? R${BR {$ {ZtR st{$s JZ } 8$ } BPZtI$9s t j {BtB{$8$ t B {$ t ? h{B Vj ZtsR R $8s{$Bt R R t{$jjsR skZIst s {Zst $h{s js % s{$IsI I sj R s Z8 t BR ]sIs {s}? ZjB $t{jZk P t{$sR -}j? {$ sR s } j? {ZjsR k tB% jsR I j ? t B Ns js{$? Bt I ? ZjBR JZ R {$ st tB R t$ } tI R -YsZR $%s ej ? ZjB I j j$A B tB R? BjB 4 `s jBR sR} { BR I RZ {Bt t$IB {$ t{$s h{{$? Bt k P? R${s R$tB js } B}$s R Z{ Z s I j - BU }B Zt jsIB R ? s $t Bt 8$ B k s JZ $}B I RBR R R Pst ? sR ${BR {Bt jBR JZ js {$ t{$s h{{$? Bt tBR s{BR Z8A s s RB } tI * RZ 8stB R $t${$s R %$s` _B B B R ? s VjA e$tR $t 8BI jB k P t I j RsA$B $8s t }B st B I js {$ t{$s 7ZR B ? sR s Zs Ist sj htsj I j {B $IB wB sj % 9 R s I Zt tZ %B }Zt B I }s $Is Ys{$s j PZ Z BD V8ABR } RBts` R $8s $ts $B k I R8 RZ sIB ZtB sj k I } BAsIs stI 9s $t j { Zsj j B B } R t st j } B RB YsA$IB t js {B8} tR$? Bt I jBR P t? B8 tBR P? R${BRU Zt s%st{ JZ %s I RI jsR R t{$jjsR j k R I R{sjs YsR s js 8? sR 8BI ts B ? s I js js $%$IsI O }Z R BR s AZR{s 8? sR stsjB ? sR j B $js w j 8BtBD k j YB8A {BtR $ Zk t s8A$? t Y$ BR t js %BjZ{$? Bt I js s9s YZ8sts {B8B R} {$ et j
NBR st { I t R I R - B R t{Z t st t tZ R B j$A B 3? R${s $ {$r t{$sTh{{$? B weI${$BtR =_] s { jBts d ;D ej j$A B RB}B I$I? s{ ${B I js sR$ ts Z s I j 8$R8B ? ZjB $ t Zt tPBJZ 8s {sIs8 t s{sI? 8${B I$ $ $IB {B8B R ? s s R ZI$st R Zt$% R$ s $BR i 8$ $8BR sj j { B $t T RsIB JZ I R } BPZtI$9s t sj ZtB I jBR 8sR -}Z R BR t js } R t BA s B t B BR sht R s I${YB j$A B k s jsR P t{$sR JZ t ? j R {$ st @
} $8 {s}? ZjB stsj$9s8BR js $8}BR$A$j$IsI I $tR { BR {BjBRsj R k B $jsR {B8B $t Bt s }s $ I jsR j k R I R{sjs yt{ ? Aj R YB8A R 8 t Zst R k Zt$% RBR RZA8${ BR{? B}${BR {Bt t$IBR t Zts B s I s Zs {B8}j st Zt R$tZBRB $ $t s $B }B 8ZtIBR $8}BR$Aj R et j {s}? ZjB R ZtIB B8stIB Z8AB Ys{$s j B{? stB I js tB{Y %$%$ 8BR Zts % IsI s BI$R s t j R}s{$B _? hIsR R$ tsR s%$ s B $sR jj %s ? st tZ R s ts% s 8ZtIBR I s}jsR st s% IsI k s j$%$stsR eR jjsR I js Z =ts - tRs sj ? s I RZ} Y? B R I RI 7Z} 8st sj <B8A yt%$R$Aj I Rhjst s jB js B I j { {s}? ZjB 7Bt BA` B I st? sj$R$R RZR w} RZt BRD RZ} }BI R k RB } tI t R s $jZ $BR JZ }s { t P stJZ s jBR } B}$BR j? 8$ R I js P? R${s 7 ? s j 8B8 t B I Ys{ Asjst{ I j ZRB wk sAZRBD I js 8 {? st${s t b Bt$sts t js {$ t{$s h{{$? Bt et j {s}? ZjB {Zs B jsR P t? B8 tBR j? { ${BR tBR I R} s ? st I j RZ K tB I js $t8B sj$IsI t sIBR }B z? { B 3 st, tR $t k B BR RsA$BR jB{BR {Bt sR}$ s{$Bt R I$%$tsR et j JZ$t B {s}? ZjB s{B8}sK ts 8BR s 8 s $BR %$s` BR t RZ { Z9sIs sj { t B I js q$ s ZtIBR I %sR sIBR }B YBjB{sZR BR tZ{j s R k $ sR st sIsR }B B{? stBR $tht$ BR R ? st B BR I jBR }s sI$R? s{BR I R $tBR I R {B $IB }B js w5}BR$Aj 2D Y$R B $s PZ Z s I j }jst s q$ s VAstIBtstIB jsR {BtPB sAj R B $jjsR I js P? R${s {j? sR${s t j R - B k Z ?j $8B {s}? ZjB tBR RZ8 $ 8BR t j } B{ jBRB 8s I j $ 8}B t 8$R$? Bt I R{s I ts? ZP s BR I j $ 8}B RB stIB { BtBR ? R8BR k }s sIB`sR 8}B sj R e8ZjstIB s jBR 8 s $BR $}Zjst R I js ts% et } $R Y 8BR $t t sIB {B8B ks B BR Y${$ Bt st R "%$s`s sjj? s s IBtI tsI$ Ys R${s t }s ${Zjs D PB 8 }s BRsIB jj s " s Zt 8ZtIB t j JZ js {Zj Z s {$ t ? h{s wk js P? I j $t{Z R $BtsAj As s` {Zj Z sj I BIB {$ZIsIstB =t {BtB{$8$ t B JZ {BtR $ Zk ZtB I jBR 8? sR PsAZjBRBR j sIBR I js YZ8st$IsI `Zt B s jsR BA sR I *sj? ] %st R B B9s Z{YBR $t ? }$IBR %$s` BR tBR Yst s{B8}sK tsIB t R s BI$R s t R %$s` sjZ{$tst sj 8ZtIB I js P? R${s s s%? R I js {$ t{$s h{{$? BtU R Zt }js{ s sI { j {Bt $tZB R ? 8ZjB I j $tPs $ sAj * $JZ j s { j? B {BtB{$IB I$ B k % IsI s sj8s 8s I BIs s{ $%$IsI s ${ZjsIs sj I IB I js {$ t{$s h{{$? Bt t js =t$% R$ s _Bj$ r {t${s I ]s sjZtks Vj * et ${ z Is Z {s I ? s ${B I P? R${s ? B ${s I js =t$% R$ s I s { jBts }B RZ j { Z s { ? ${s I j {s}? ZjB I I${sIB s js P? R${s I jBR %$s` R t j $ 8}B 7ZR RZ t{$sR Yst t $JZ {$IB tB sAj 8 t j {Bt t$IB I I${YB {s}? ZjB V jBR * R V8sI Z Bt B B k is[ Zj iBI ? Z 9 I j * }s s8 t B I 3? R${s yt t$ ? s WZ{j s I js =_] }B YsA %$RsIB I$% RsR }s R I j - B s 8sIBR I }s{$ t{$s V FBR } s $s 7 s is8Bt s ? k Bt R sK t? I eI${$BtR =_] }B YsA 8st t$IB Zts P {$ s t R - B k YsA } B}B {$BtsIB BIB j RB}B 8s $sj t { Rs $B V FBst 7Bj }B RZ skZIs $t R $8sAj t js } }s s{$? Bt I j - B k t js $tR {$? Bt I $8r s t R V z${ t i$AsR }B YsA RsA$IB }jsR8s {Bt RZR $jZR s{$Bt R tZ R sR s 8 tZIB %s sR } B}Z R sR s}B stIB P R{Z s k AZ t YZ8B ? $ B RZkB R j YsA { sIB R } RBts` Zt 7Z} 8st % t$IB s 8 tBR {ZksR } $} {$sR k s 8 tZIB I R% t Z sR {B t }s sj jsR sj I Rs BjjB I j - B O t I ht$ $%s tZ R B 8? sR R$t{ B s sI {$8$ t B s jBR R{ $ B R k Z$Bt$R sR I {$ t{$s h{{$? Bt R$t {Zks $8s $ts{$? Bt R - B tZt{s YZA$ R R$IB }BR$Aj z$jstB%s $ js p j ? Z B{ ZA I d M
NBR sZ B R
*$ {{$Bt R I {B B j { ? Bt${BU 9uvY l!9C vCqY}|! R
bC I%!bCR qY}|! R
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
@
d
$t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
7BA BI$R sR t $ sR I $ st R B $jsR k YB 8$ sR {BjBRsj R RBA YB8A R 8 t Zst R st jBR JZ R$8}j R $tR { BR R $ t {B8B $ ? st${BR t 8$ BR
Ns t stIsAs sYB s }B BIB j $ st {ZkBR A s9BR {BR sIBR } B}B {$BtsAst Zts IBAj R{sj$ts s * RI jsR }sj8sR {s8$tsAst }B jBR st A s9BR YsR s j {BIB k jZ B R s sR sAst }B j Y$tT {YsIB %$ t I jBR A? { }R YsR s j jjstB }sR B I jBR 8? ZR{ZjBR } {T B sj R JZ {ZA ? st js 8$ sI RZ} $B I j } {YB j$RB k js8}$K tB * RI sjj? RZA? st s js {s s }sRstIB }B jsR 8stBR }B jBR jsA$BR k }B js ts $9 B As`sAst {B $ tIB }B j sAIB8 t }s s Zt$ R {Bt B BR JZ YsA? st }sIB s jBR BA$jjBR k }s ZjjsAst jsR {BjZ8tsR 8 jsR I jBR 8ZRjBR F p sjjs I
ej $ st sYB sIB >qY * Bbt I p$st d E;H
7$t IZIs $ t t s9? Bt jBR hj? BRBPBR {ZstIB I${ t JZ tsIs R stI B } JZ K tB R$ tB R }B {B8}s s{$? Bt F 7b$P
NBR %$s` R I pZjj$% >pZjj$% :R q s% jR d 1EH
wy9JZ$ IsD et j A R $s $B Pst ? sR ${B I js {$ t{$s h{{$? Bt B{Z}st Zt } B8$t t jZ s }B RZ s8sK tB jsR { $s Z sR $ st R VJZ? js 7 s Wst{k V {Y } B s Bt$R s I js } j? {Zjs ej s sJZ I js 8Z` I x( }$ R >V s{, BP Y x( P GB8st d ;H 8BR stIB RZ tPsIB }B j {s8A$B I h Z s 5]? B8B %Bk sYB s s }Bt 8 j s` I tB{Y JZ 8 sj? B 8$ 8s $IB2 }s { R s } tRstIB
© Los autores, 2001; © Edicions UPC, 2001.
* $t Bt s e$tR $t
u!R } R t B {Y${BR s Zts I jsR { $s Z sR 8? sR $8} R$Btst R JZ `s8? sR Yskst -$R $IB RBA js Ps9 I js q$ sU j $ stBRsZ $B z$%$? B Ys{ ZtBR R R t s 8$jjBt R I sK tBR t j { ? s{${B RZ} $B u{B8 t s s RZR R ZI$st R j } BP RB JZ I$ $ js %$R$ s sj ZR B I BBjB ? s I js {$ZIsI u $ }sI I${ JZ {Bt js }$ j I Zt I$tBRsZ $B }BI ? st Ys{ R 8$j R I ABjRBR k 9s}s BR 7 T Z B JZ I tB YsA I Rs}s {$IB }B RZ {Z t s jBR YsA ? s8BR - 8$tsIB tBRB BR u -{js8s ZtB I jBR 8Z{Ys{YBR $ t sR } BR$ Z {Bt RZR -}j${s{$Bt R u {BtR Z{{$? Bt sj$9sIs }B jBR $t% R $ sIB R I j ytR $ Z B I _sj Bt BjB ? s I 7sAsI jj s }s $ I Zts %? A s YsjjsIs t js } B%$t{$s I q Z j u jBR R ZI$st R R ? st } tI$ t R I Zt j `stB Z8B } jZI$B I Zts }BR$Aj B T 8 t s JZ }s { s{ {s R {Bt j t $ ZI u A? } IB I 8? sR I R$ 8 BR I sj Z s {s t? %B B ej Z8B R {Bt%$ t Zt RB IB R Z tIB j RZ jB 8}$ 9s s 8Ajs %$A st jsR s{ $R sjsIsR }s I R =ts jjZ%$s I { $R sj R B BR {s I RI j {YB I js %sR s Rsjs O js I R{B8Ztsj }s s I Zt I Zt A$ t I Zt 8BtR ZB $ st R{B IZ{ s }Bj%B j RJZ j B I $ stBRsZ $B ej $t{Bt{ A$Aj pBI9$jjs sR RZ }sRB I %sR sIB }B qB,$B k WZ %s OB , s{sAs I jj s s s { jBts eR YB s I gRsj$ {B $ tIB NBR {s8A$BR I R{sjs Yst {BtR $ Z$IB Zt 8s {Z t t js j$ s Z s k j PBj{jB I BIBR jBR $ 8}BR * RI jBR $t PsAj R ps Ast{$ B B _s ZP R R I sjjs I$8$tZ s } B s Bt$R sR I {Z t BR $tPst $j R YsR s jBR j$j$}Z $ tR R I 7b$P }sRstIB }B j ${ B8 sR I zBj s$ B j {BjBRsj ps st ? Zs I isA js$R $ st R k YZ8stBR t 8$t$s Z s RBt jBR }BAjsIB R I 8Z{YsR Pst sR? sR js BR k j k tIsR eR{ $A isA js$RU "* } JZ K tB j PZ Bt R %sIsR s ps st ? Zs I$ {$R$ 8$j tB% {$ t sR { %s{sR }s s s tI s RZ tB 8sj { $st9s }Z R tB s }BR$Aj t{Bt s t BIB j }s? R tBI $9s {s}s9 I sj$8 t s jB IsIs js st {st $IsI I j {Y JZ t { R$ sAs et js {BtP {{$? Bt I RZ {s8$Rs R sR s Bt tB% {$ t sR %s sR I js k 8$j {$ t B {$t{B %s sR R 8}j s Bt t jsR {sj9sR * `B% t PZ t%$sIB s R ZI$s s _s ? R s jB8BR I Zts k Zs st stI {B8B R $R j Pst R k s js JZ s 8BIB I {sR{sA j R {Bj ? B jsR {s8}stsR I W| B *s8 V s{sIB s {sK tBts9BR I RI Zt {sR $jjB R JZ$ ? B jsR AsjsR I {sK t? Bt JZ R j YsA? st JZ IsIB t jBR {sA jjBR {Bt RZ } $t TJZ 8 I? s {$t{Z t s k R $R }sj8BR {Bt jsR }? ZsR Y {YsR I {Bj8$jjBR t BR I j Pst 7 {B8$? B Zts tRsjsIs I j {YZ sR I j s8sK tB I Zt tB sj k R $R } $tBR JZ t jjsR R YsA? st PZ $sIB " NsR $t{BtR$R t{$sR k -s s{$Bt R JZ R s} {$st t R $}B I js BR $ t t RZ `ZR $h{s{$? Bt t js $t t{$Btsj$IsI I j sZ B I $I${Zj$9s I$P t R sR} { BR I js sj$IsI I RZ $ 8}B {B8B R ? s s8A$? t j {sRB I FBts Yst 7b$P t jBR Ps8BRBR z$s` R I pZjj$% >pZjj$% :R q s% jR d 1EH 7 s s I Y$R B $sR JZ R t{ZsI st I t B I jB JZ R Ys IsIB t jjs8s js j$ s Z s Rs ? ${s IBtI t R {sRB j `Z B I jsR I$8 tR$Bt R } 8$ sj$9s Zts { ? ${s I %sR sIB s I jsR sI${$Bt R 8? sR s s$ sIsR k R$ ? Zst sj j { B st Zts tZ %s %$R$? Bt I tZ R B } B}$B 8ZtIB 7? s $ sR 8? sR {$ t R jsR t{Bt s8BR t jBR js BR qY qYBZRstI O s R s8Bt Y ${ BA R >d (xH I s , qbs$t IBtI R ts st jsR s% t Z sR I Zt 8 t jjs8sIB <Z{, t j $t $B I j {Z }B YZ8stB JZ YsA$ s k ej $ st sYB sIB >qY * Bbt I p$st d E;H I F p sjjs I Zts I 8Bj IB s Y$R B $s RBA j I R $tB htsj I Zt $ st YZ8stB JZ s}s { sYB sIB t Zts }jsks
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
@
_ B R t j {$t IBtI js 8BIs I jBR {s8A$BR I s8sK tB { t sIs }B RZ R} { s{Zjs $IsI t j $ st $R8B R ? s -}jB sIs YsR s js Rs{$ IsI Z{YsR } j? {ZjsR {j? sR${sR I {$ t{$s h{{$? Bt JZ s} jst s R $}B I {Z RBR {BtR $ Zk t Zt h j 4 `B I jsR PBA$sR k 8B R I Zts YZ8st$IsI JZ Ys }sI {$IB IBR Z sR 8ZtI$sj R V I$P t{$s I jsR R? s $ sR {$ sIsR jBR Z$Bt$R sR } tI t Is Zts $8s t I { I$A$j$IsI s jsR }Z R sR t R{ ts {Z $ tIB s js {$ t{$s isI$s{$Bt R 8$R $BRsR B RB } tI t R P $j$9st R RBt {sR$ R$ 8} js {sZRs I js s8}j$s{$? Bt B I js IZ{{$? Bt I R R %$%BR eR BR hj8 R I s Z8 t B R$8$js w8BtR ZBT JZ I R}$ s I RZ j s BTs s{s YZ8stBRD {BtR $ Zk t Zts PZ t $ts B sAj I { $s Z sR 8BtR ZBR sj$ t? tsR k B ? h{BR $tR { BR I Zt s8sK tB sj JZ %$Bjst jBR } $t{$}$BR 8? sR j 8 t sj R I jsR j k R I R{sjs ej sAst${B I { $s Z sR $ st R R s8}j$B k %s $sIB etT {Bt s8BR B $jsR w $t Bt >d nnHD {st `BR wV s{, BP Y ] sA BtR R >d x HD }Zj}BR wy ]s8 P B8 t s Y Y 7 s >d xxHD I$tBRsZ $BR 8Z st R wFs}? Bt As`B j B I j 8BtT R ZB >pBI9$jjs $t BP Y BtR R d x;HD Rst Z$`Z jsR wV s{, BP Y p$st N {Y R >d E(HD YB 8$ sR wNs YZ8st$IsI t } j$ B >qY 8 d x;HD s sK tsR wqs ? st Zjs >d xxHD 8st $R j$ $BRsR wej 8BtR ZB sjsIB >qY * sIjk st $R d x HD jst BR sR wqY $tt$t BP Y etI >d x HD $tR { BR %s $BR wqY ]BR8${ BtR >d xMHD e- sB I$ts $BR R R JZ }B jB t sj R$ tT t Zts R} {$sj } I$j {{$? Bt }B } R Z$ s %sj$ t R Y B? tsR 7$8}j R s Z8 t BR AsRsIBR t j st? sj$R$R I jsR 8s t$ ZI R P? R${sR $t%BjZ{ sIsR } 8$ t 8BR s js $t{Bt Z t{$s I R BR Pst ? sR ${BR R RU t js %$Is sj tZt{s }BI ? st jj s s -$R $ d d V t{$? BtU {Z$IsIB {Bt jsR YB 8$ sR
Ns sI${$? Bt 8BI ts I { $s Z sR $ st R 8}$ 9s {Bt Zts tB% js I j } Bj? h{B R{ $ B $t j? R < A p B G jjR wdMEMTd ;ED ej sj$8 t B I jBR I$BR R >qY 3BBI BP Y pBIR d (;H IBtI Zt 8$js BRB P $j$9st wjs Y s{j BPB A$s B j sj$8 t B I Zt <? {Zj RD Is jZ s s }jst sR st$8sj R k YsR s YB8A R $ st R G jjR I R{ $A ZtsR s%$R}sR JZ Yst -} $8 t sIB Zt { {$8$ t B I ZtsR n( % { RU "]ZstIB R I {$I$? B s 8 I$ js %$B JZ t? s R t s { t ? 8 BR I Zts }Zt s I j sjs s js B s k j s Z$`? Bt B{YB ej sAIB8 t YsA? s R sjjsIB }B js 8$ sI } B R $8? B js jBt $ ZI I j st$8sj I js {sA 9s sj s Z$`? Bt {B8B I ZtBR {Zs t s k {$t{B { t ? 8 BR jB JZ R {sR$ -s{ B 7ZR B`BR {B8}Z R BR st I j s8sK tB I 8Bt IsR I Zt } t$JZ " qsj R s%$R}sR $ st R tB R ? st {s}s{ R I %Bjs $ t sR JZ js RZ} h{$ I RZR sjsR JZ R } B}B {$Btsj sj {ZsI sIB I RZ s8sK tB Ys sZ8 t sIB n(1 % { R j $t{ 8 t B -} $8 t sIB }B RZ } RB } B}B {$Btsj sj {ZAB I RZ s8sK tB Ys R$IB 8Z{YB 8skB U n(n % { R w]ZsI B d dD Ns js{$? Bt t js RZ} h{$ I jsR sjsR k j } RB I js s%$R}s $ st tB R 8st $ t $ Zsj JZ t js s%$R}s tB 8sj et {BtR {Z t{$s js s%$R}s $ st tZt{s }BI ? s %Bjs G jjR %s 8? sR sjj? s t RZ Y$R B $s k tBR } R t s Zt 8ZtIB I$R B R$BtsIB IBtI j }BI I j sj$8 t B tB }Z I R {Bt BjsIB k js YZ8st$IsI R I$%$I t jBR p$ st R w{ $s Z sR JZ Yst $t $IB j sj$8 t BD k jBR _ JZ K tBR w j R B I 8B sj RD NsR YB 8$ sR 8Z st R I 8? sR I d( 8 I s8sK tB JZ s}s { t t j hj8 Ns YZ8st$IsI t } j$ B RBt j RZj sIB I js -}BR${$? Bt I YB 8$ sR {B8Zt R s js sI$s{$? Bt {sZRsIs }B jsR } Z AsR s ? B8${sR sj$9sIsR t j I R$ B I V $9Bts }B 8$j$ s R tB s8 ${stBR 7 tP t st s jBR R R YZ8stBR t Zt s%st{ $8}s sAj JZ jsR jj %s YsR s js 8$R8s {$ZIsI I
© Los autores, 2001; © Edicions UPC, 2001.
* $t Bt s e$tR $t
]ZsI B d d N k {ZsI sIBT{? ZA${s <s{ 8? sR I R R$ jBR JZ j {$ t ? h{B $ sj$stB psj$j B wdxE;TdE;1D tZt{$? B js I tB8$T tsIs JZ R sAj { jB R$ Z$ t U {ZstIB Zt BA` B { { R$t {s8A$s I PB 8s RZ RZ} h{$ sZ8 t s {B8B j {ZsI sIB I Zts jBt $ ZI {s s{ ? R ${s I j 8$R8B w}B ` 8}jB RZ sj Z sD 8$ t sR JZ j %BjZ8 t { { {B8B j {ZAB I I${Ys jBt $ ZI e-$R t } B}$ IsI R P? R${sR I Zt {Z }B JZ I } tI t I RZ RZ} h{$ k B sR I RZ %BjZ8 t NsR } B}$ IsI R JZ I } tI t I j %BjZ8 t { { t 8? sR ? s}$Is8 t {Bt j sZ8 t B I j s8sK tB JZ jsR } B}$ IsI R JZ I } tI t I js RZ} h{$ et {BtR {Z tT {$s Zts %s $s{$? Bt I j s8sK tB {B8}B s ? s s 8 tZIB I$P t{$sR tB sAj R y8s $t 8BR {B8B R 8Z R s I PB 8s RJZ 8? s ${s t js h Z s IBR 8st9stsR B8? ${s8 t R T 8 `st R Zts IBR % { R 8skB JZ js B s JZ } tI t I Zt s ? ABj ej } RB I Zts 8st9sts R $ Zsj sj } BIZ{ B I js 8sRs }B js s% IsI V RZ % 9 js 8sRs R j } BT IZ{ B I js I tR$IsI I js 8s $s I JZ R ? s {BtR $ Z$Is }B j %BjZ8 t JZ B{Z}s ]B8B j %BjZ8 t R } B}B {$Btsj sj {ZAB I j sI$B RZj s JZ s $ ZsjIsI I I tR$IsI R ws8AsR 8st9stsR }BR t js 8$R8sD k }s s Zt 8$R8B %sjB I js s% IsI j %BjZ8 t k ts }B st B j } RB I js 8st9sts 8? sR stI R Zt Ps{ B 1n 8skB JZ j I js } JZ K _B B B jsIB j } I? Zt{ZjB JZ Zt js } $8 s 8st9sts sj s ? ABj $ t s8A$? t Zt sI$B IBAj JZ j I js R ZtIs Ns {s}s{$IsI I j } I? Zt{ZjB }s s RBR t } RB R I {$ RZ R$R t{$s %$ t IsIs }B js RZ} h{$ I RZ R {{$? Bt stR% Rsj js {Zsj R } B}B {$Btsj sj {ZsI sIB I RZ sI$B VR? js R$R t{$s I j } I? Zt{ZjB 8skB R 11 % { R js I j 8 tB Ns 8st9sts stI $ t Zt } RB B{YB % { R RZ} $B sj I js } JZ K ts 8$ t sR JZ js R$R t{$s I j } I? Zt{ZjB R R? BjB {Zs B % { R 8skB U t sj ? Zt 8B8 t B js 8st9sts JZ {Bt $t? Zs { {$ tIB s{sAs ? s I PB 8s $t %$ sAj }B {s sj RZ jB !AR % 8BR {? B8B jBR sR B {sjsAs9sRD tB } tI t I RZR sjjBR R$tB P Z BR stI R w sj R {B8B 8 jBt R RstI? JZ RZ t s sR I RZ jB j k {ZsI sIBT{? ZA${s
i } R t s{$? Bt RJZ 8? s ${s I IBR 8st9stsR JZ } tI t I Zt ? s ABj B t }BR${$? Bt $t% $Is I Zt st$8sj {Bt }s sR ej BA` B 8? sR stI R $t ? tR {s8 t 8? sR I? A$j JZ j } JZ K tB
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
1n
7$ sYB s $t% $8BR js h Z s w $ s8BR js }? s $tsD }BI 8BR t Zt RJZ 8s s} B-$8sIB I Zt st$8sjU Zt {Z }B w RP sD IBtI R$I js 8skB }s I js 8sRs k ZtsR }s sR B }$ tsR w{BjZ8tsD JZ jB RBR $ t t ej st? sj$R$R I js R$R t{$s I R s AsR R t R t{$s $I? t ${B sj {sRB st $B s -{ }{$? Bt Y {Ys I JZ sYB s js {BjZ8ts I RBR ? t R Ysjjs {B8} $8$Is k tB RB8 $Is s Zts tR$? Bt V 8 I$Is JZ sZ8 t s j s8sK tB I j BA` B j } RB { { 8? sR ? s}$Is8 t JZ js R$R t{$s I RZ RB}B k s{sAs $t %$ sAj 8 t }B tB }BI RBR t js R Z{ Z s e-$R }Z R Zt s8sK tB 8? s-$8B }s s jBR BA` BR I {ZsjJZ$ 8s $sj
*BR h Z sR B8? ${s8 t R 8 `st R I s8sK tB I$P t Ns s9? Bt t jsR jBt $ ZI R I IBR R 8 t BR YB8? BjB BR {Zsj RJZ$ s I s8AsR h Z sR Zs Is Zts js{$? Bt {BtR st I tB8$tsIs Ps{ B ) _B ` 8}jB t Zts s8}j$s{$? Bt PB B ? sh{s jsR } B}B {$Bt R -$R t R t jsR I R{sjsU I$P t R }s R I j BA` B s8}j$sIB RBt jsR 8$R8sR JZ jsR I j B $ $tsj G G1 3 31
© Los autores, 2001; © Edicions UPC, 2001.
1;
* $t Bt s e$tR $t
NBR Vt j R _BI 8BR R $8s j } RB I R sR YB 8$ sR $ st R s }s $ I j s8sK tB I Zts YB 8$ s sj wI s} B-$8sIs8 t d {8D I d ]B8B j Ps{ B I R{sjs I s8}j$s{$? Bt R R sR R ? st d!(((n % { R 8? sR } RsIsR R I {$ tI ? st Zt } RB I d!((( d( 8>d {8 ) d!((( ? Bt jsIsR _Z R B JZ jsR YB 8$ sR R ? Zt R I${ RBt 8? sR PZ R JZ j YB8A 5}BI ? st R {s}s{ R RZR YB8? BjB sR $ st R I RB}B s R $t{ ? Aj } RB k }B st B I RI j }Zt B I %$R s I jsR j k R I R{sjs }BI ? s8BR s{ } s RZ %$sA$j$IsI2 =ts YB 8$ s sj }Z I j %st s YsR s R % { R RZ } B}$B } RB R I {$ }BR Zts PZ 9s js $%s $ Zsj s n $ t sR JZ }B RZ }s Zt YB8A {B8? Zt }Z I j %st s Zt } RB R 8 `st sj I RZ {Z }B R I {$ $ t Zts PZ 9s js $%s } ? B-$8s s d wsj ZtsR } RBtsR sj B 8? sR {js B } B }B ? 8$tB 8 I$B ? R R Zt %sjB s9BtsAj D 57$ t$h{s R B JZ jsR YB 8$ sR RBt 8? sR PZ R JZ j YB8A 2 _s s sj$9s R $}B I {B8}s s{$Bt R I A 8BR B A$ t IZ{$ j YB8A sj s8sK tB I Zts YB 8$ s B A$ t $t{ 8 t s jsR I$8 tR$Bt R I ? R s YsR s Zts 8 I$Is R$8$js s js I j YB8A 7$ {BtR$I s8BR R s R ZtIs }BR$A$j$IsI wYB 8$ sR sZ8 t sIsR t Zt Ps{ B I R{sjs dM( {8>d {8 ) dM(D RZj s JZ jsR YB 8$ sR $ st R $ t t R ${sR Zts PZ 9s js $%s {BtR$I sAj 8 t 8 tB $ Zsj s d>E( =t $tR { B I R sR {s s{ ? tB }BI ? s t$ st R$JZ$ s j %st s RZR }s sR }s s {s8$ts B RZ} s BAR ? s{ZjBR =ts YB 8$ s I j s8sK tB I Zts } RBts R ? s Zts { $s Z s }s ? ${s8 t B R{s $t{s}s9 I RBR t R }B R? 8$R8s Zt R s BIsR jZ{ R $t%$sAj Vj B }s {$IB j RZ{ I ? s s js $ st R{s s sK ts I js } j? {Zjs qs ? st Zjs JZ % s8}j$sIB RZ s8sK tB ZtsR d(( % { R sj R $tk { sIs {Bt Zt tZ $ t -} $8 t sj JZ {sZRs j $ st $R8B t jBR st$8sj R et qY p$st 7}$I yt%sR$Bt >d xH } j? {Zjs I t PsR BR P { BR R} {$sj R {B IsIs }B Z $j$9s Zt sZ B8? B%$j zBj,Rbs t 8BI$h{sIB }s s { s sj s ? s{t$IB $ st jsR s sK tsR 8 t I Zt s Z` B t B k s B $9st s Zts }s{? h{s }BAjs{$? Bt y8} BAsAj R $tR { BR $ st R k s sK tsR 8BtR ZBRsR } R$ Z t s8A$? t s jBR $tPB ZtsIBR YZ8stBR t j js B qY 3B B t _jst >d x;H I Z sk N $tR JZ$ t tB% js ? s s8A$? t sj ZtBR I jBR }$RBI$BR I js R $ I qz q$ s I $ st R >NstI BP p$st R d EMT (H k t js Rs s 7}$I GB jI >d M T 1H I ]Bj$t G$jRBt Ns {$ t } j? {Zjs $8${ >d H sIBj { I jBR 8$R8BR I P { BR I jsR } j? {ZjsR {Bt $tR { B $ st I jBR sK tBR {$t{Z t s s jsR JZ } tI$Is8 t }s { JZ $8$ s =ts R} {$ I $tR { BR { sIBR t Zt jsAB s B $B }s s s{sAs {Bt Zts }js s I {Z{s s{YsR {B8Zt R 8Z st {Bt%$ $? tIBR t { $s Z sR I 8? sR I IBR 8 BR I sj Z s {Bt B ? stBR } B}$BR I j YB8A {B8B }Zj8Bt R } B 8st t$ tIB jsR } B}B {$Bt R I RZR YB8? BjB sR sj R 5* JZ? j R R$ % t s R BR I R{B8Ztsj R $tR { BR ZtsR sjsR t Zt Y? sA$ s st IZ{$IB }s s RZ s8sK tB {B8B jBR ? Zt j R I j 8 B2 5]? B8B }Z I t I `s -{ 8 t BR I ZtsR {Zst sR I { tsR I ,$jBR I } RB t j {YB JZ sIB} st sI 8? sR js PB 8s I Zt {BtB $t% $IB R$t JZ R j R % t st t{$8s2 7Bt B sR st sR {Z R $Bt R JZ YsA ? s JZ I$ $ $ s jBR Z$Bt$R sR I j hj8 5eR t { Rs $B sK tsI$ sj B 8? sR s{ {s I RsR $8}BR$Aj R YB 8$ sR k s sK tsR $ st R JZ s}s { t t jsR } j? {ZjsR k tB% jsR {B8 t sIsR2 W$t Zts { I$A$j$IsI }Z I B B s R }Z R s Rs j $? Bt I $tR { BR s $ st sIBR JZ {s8} st s RZR st{YsR }B j s } Rs I jjB R$ 8} PsR{$tst 8ZtIB I js {$ t{$s h{{$? Bt NsR } B}B {$Bt R I Zt st$8sj js PB 8s I RZ {Z }B I jsR }s sR B I jsR sjsR R ? st {BtI$T {$BtsIsR }B RZ s8sK tB k RZj s ? st sARZ IsR R$ ? R {s8A$sR R$t 8BI$h{s I PB 8s sI {ZsIs
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
N
]ZsI B d 1 3Z 9s js $%s Ns PZ 9s JZ }Z I sj$9s Zt st$8sj I } tI I js R {{$? Bt stR% Rsj I RZR 8? ZR{ZjBR i {B I 8BR }B ` 8}jB JZ Zt AZ t j %st sIB I } RB I A t ZtBR A s9BR k ZtsR }$ tsR I R {{$? Bt stI * ht$8BR js PZ 9s js $%s I Zt st$8sj {B8B j {B{$ t t j } RB JZ }Z I j %st s JZ R $ Zsj s js PZ 9s JZ }Z I sj$9s k RZ } B}$B } RBU _ RB JZ }Z I j %st s 3Z 9s js $%s ) _ RB I j st$8sj *sIB JZ j tZ8 sIB I } tI I js RZ} h{$ wJZ R } B}B {$Btsj sj {ZsI sIB I Zts jBt $ ZI {s s{ ? R ${s qD k j I tB8$tsIB I } tI I j %BjZ8 t w} B}B {$Btsj s n q D RZj s JZ R {B{$ t R $t% Rs8 t } B}B {$Btsj sj s8sK tB I j st$8sj eR B R$ t$h{s JZ js PZ 9s js $%s I Zt st$8sj B I Zts R Z{ Z s w{BjZ8ts D R $t% T Rs8 t } B}B {$Btsj sj s8sK tB 7$ {B8}s s8BR jsR PZ 9sR js $%sR I IBR st$8sj R B8? ${s8 t R 8 `st R j 8? sR stI tI ? s R$ 8} Zts PZ 9s js $%s 8 tB eR }B st B 8? sR I? A$j RZ R Z{ Z s NBR YZ RBR I jBR st$8sj R stI R RBt I R} B}B {$BtsIs8 t 8? sR st{YBR k BAZR BR JZ jBR YZ RBR k 8? ZR{ZjBR I jBR st$8sj R } JZ K tBR NsR }s sR I Zt j Pst RBt 8? sR 8s{$9sR k {$sR t {B8}s s{$? Bt JZ jsR I Zt $tR { B ej Bt{B I Zt s ? ABj sIZj B R } B}B {$Btsj8 t 8? sR Z RB JZ j I Zt s ABj$ B 7$ I R s8BR sZ8 t s js PZ 9s js $%s B R$R t{$s I j R$R 8s R ? s t { Rs $B 8BI$h{s RZR } B}B {$Bt R k }B st B {s8A$s RZ PB 8s _B ` 8}jB }BI 8BR I$R K ts Zts { $s Z s I st s8sK tB 8BI$h{stIB js R {{$? Bt I jsR }s sR I Zt $tR { B }s s {BtR Z$ Zt sZ8 t B I js R$R t{$s I js R Z{ Z s I RBR ? t } B j $tR { B $ st R }s { ? s 8Zk }B{B sj B $ $tsj et js } j? {Zjs $t Bt R B8? B {B8B 8BI jB s Zt B $js I 1n( , I 8sRs k d, M( 8 I R s Z s k R sZ8 t s Bt } B}B {$Btsj8 t RZR I$8 tR$Bt R }s s { s sj B $js $ st I 13 (( , eR s 8sRs RZj s 8Zk } JZ K ts R$ I jB JZ R s sAs s I BA t Zt 8BI jB s R{sjs I B $js 7$ js { $s Z s YZA$ R R sIB {B { s8 t I$8 tR$BtsIs YsR s j s8sK tB I ZtBR dx 8 JZ }s { t t j hj8 wjB JZ } R t s Zt Ps{ B I R{sjs I s} B-$8sIs8 t B{YBU dxbd, M ) M, nD RZ 8sRs sj YZA$ R R$IB M, nn % { R 8skB JZ js I Zt B $js sj I R s Z s R$8$js s js I Zt YB8A I d, M( 8 R I {$ ZtsR gdn( Bt jsIsR =t 8BtR ZB I R sR {s s{ ? R ${sR I$P? {$j8 t }BI ? s R st s ? $j {B8B }s s R{sjs Zt sR{s{$ jBR sj {B8B R BAR %s t js 8 8B sAj R{ ts htsj I j hj8 _BR$Aj 8 t t$ st R$JZ$ s YZA$ s R$IB {s}s9 I 8st t R Z$IB ej qk sttBRsZ ZR i - JZ R j st$8sj A? } IB 8? sR stI JZ Ys -$R $IB t js q$ s } RsAs RBjs8 t gE Bt jsIsR WB R {sRZsj JZ jBR st$8sj R 8? sR stI R R t{Z t t t j 8s et j s Zs j 8}Z` I V JZ? 8 I R JZ R B}Bt s js PZ 9s I js s% IsI w} RBD k R } B}B {$Btsj sj %BjZ8 t I j BA` B RZ8 $IB `Z s Zt }s} j tB sAj w t j s$ R s PZ 9s R I R} {$sAj t {B8}s s{$? Bt {Bt j } RB IsIB JZ RZ %sjB I } tI s8A$? t I js I tR$IsI I j 4Z$IBD Ns Asjj ts s9Zj }Z I jj s s } Rs YsR s d ( Bt jsIsR 8$ t sR JZ Zt j Pst tB RBA }sRs jsR d( Bt jsIsR
© Los autores, 2001; © Edicions UPC, 2001.
-
* $t Bt s e$tR $t
3$ d d wV $AsD =ts I jsR YB 8$ sR $ st R I js } j? {Zjs Ns YZ8st$IsI t } j$ B >qY 8 d x;H } R$ Z$ tIB s js IB{ B s IPB I js $t ? }$Is } B s Bt$R s NsR - 8$IsI R I js YB 8$ s }s { t I 8sR$sIB P ? s $j R {B8B }s s RB}B s j } RB I RZ {BjBRsj {Z }B wVAs`BD Ns s sK ts I j hj8 qs ? st Zjs >qs st Zjs d xxH st j } BP RB * 8 IZ st j } B{ RB I { {$8$ t B I R8 RZ sIB
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
1
3$ d 1 =ts Y$}B ? ${s s8 ts9s JZ tB R sj
Ns Asjj ts R j st$8sj 8? sR } RsIB t {s8A$B RZR YZ RBR tB RBt } B}B {$Btsj8 t 8? sR Z RBR =ts { $s Z s I RZR {s s{ ? R ${sR tB }BI ? s %$%$ t js RZ} h{$ R * Y {YB Zts Asjj ts %s sIs t js }jsks 8B $ ? s sRh-$sIsU RZ R Z{ Z s B ?R s R ? s $t{s}s9 I RB}B s j } RB I j st$8sj eR{ $A sjjs I t RZ js B ej $ st sYB sIBU "VZtJZ jBR sjBt R R sAst }s {$sj8 t YZtI$IBR t js s ts jBR }$ R R sj9sAst s }B jB 8 tBR j IBAj I js R s Z s I jBR } R{sIB R k {B8} tI$8BR $t8 I$s s8 t JZ R j %$s ? st sYB sIB t? s js 8sRs k jsR I$8 tR$Bt R I Zts Asjj ts" et ej sj$8 t B I jBR I$BR R >qY 3BBI BP Y pBIR d EH js sIs} s{$? Bt {$t 8s B ? sh{s I js tB% js YB8? Bt$8s I G jjR s}s { Zts j $? Bt I s sR $ st R{sR s8}j$sIsR R ? Zt Zt Ps{ B I R{sjs I n( Ns } j? {Zjs 8Z R s s jsR s sR {s8$tstIB }B j RZ jB R$t t$t ? Zt } BAj 8s k sYB ? stIBR {ZstIB $t t st s s% Rs s tsIB Zt ? B ej } B s Bt$R s {B8 t s R Z ?j $8B Y {YB s Z8 t stIB JZ IsIB JZ jsR s sR Yst sZ8 t sIB I } RB R tB 8sj JZ tB }Z Ist 8st t R t j s Zs jB {Zsj R {sZRs I RZ YZtI$8$ t B eR s9Bts8$ t B R I j BIB $t{B { B }Z R B JZ R } {$Rs8 t t j s Zs IBtI j tB 8 } RB I RZR {B }s{YBt R R % I$R8$tZ$IB }B j P { B I j 8}Z` I V JZ? 8 I R 7Bt t BIB {sRB jBR s ? $j R 8B%$8$ t BR }B j RZ jB I RZR {Bt ? t R tB 8sj R jBR JZ R sR s sR $ st R R ? st $t{s}s{ R I } BIZ{$ B t? stIBR st$8sj R B }Bt R k I 8B%$8$ t BR j t BR k } RsIBR JZ j R $8} $8$ ? st ZtsR s ${Zjs{$Bt R k ZtsR }s sR tB sIs} sIsR s R s8sK tB et jBR - 8BR I js -s s{$? Bt js tZjs BAR %s{$? Bt I jsR j k R I R{sjs Ys jj %sIB s I R} B}? BR$ BR sj R {B8B jsR } j? {ZjsR RBA pBI9$jjs ZtB I jBR 8BtR ZBR {Bt } 8$RB I j B $js $t Bt 8? sR Ps8BRBR I BIBR jBR $ 8}BR 7 s s I Zt I$tBRsZ $B sthA$B 8Z st I gd1( 8 {s}s9 {B8B jBR 8$ Bj? B ${BR I s Bt R I s B`s PZ B }B RZ AB{s 7Z tB8A % R$? Bt st j${st$9sIs I j B $ $tsj `s}Bt? R pB`$ s R Zts }sjsA s {B8}Z R s I B $js k ,Z`$ s wAsjj tsD k Zt {js B ` 8}jB I js Y$js st $8s $ts{$? Bt I RZR { sIB R et j 8BtR ZB R Ysjjst sj ? B ${s8 t } R t sIBR j 8B k jsR Y $IsR s? Zt sA$ sR I Zt Fs}? Bt JZ
© Los autores, 2001; © Edicions UPC, 2001.
1M
* $t Bt s e$tR $t
3$ d n ]B8}s s{$? Bt I jsR I$8 tR$Bt R I I$P t R B st$R8BR wsIs} sIB I qs8sK tB k %$Is q V { sYBt k F q Btt d ME RBA Zt B $ $tsj I G jjR <Z-j k k G jjR d n1D I$AZ`sIBR s js 8$R8s R{sjsU d js 8skB s% %BjsIB sU j sjAs BR 1 j 8skB st$8sj {BtB{$IBU js Asjj ts s9Zj n j 8skB 8s8? P B R - $t BU sjZ{Y$ Y $Z8 ; j st$8sj R %$%B 8? sR sj BU js `$ sPs x j A? } IB I 8skB s8sK tBU qk sttBRsZ ZR - E *$}jBIB{ZR ZtB I jBR 8skB R } $j R %BjsIB RU _ stBIBt M js 8skB R }$ t - $t s jBt $ ZI I js 8skB t$s t{Bt sIs t j YB8A d( j } $j 8? sR js B %$%BU j {B{BI $jB sP ${stB dd j 8skB js s B - $t B d1 js 8skB s% - $t sU V }k Bt$R dn js 8skB 8 IZRsU ]kst s d; j 8skB js s B %$%BU j I s ? Bt I B8BIB dx B% `s dE j 8skB 8BjZR{B A$%sj%BU q $Is{ts d j 8skB } 9U j $AZ ? Bt Asjj ts dM {sAsjjB d j 8skB { ZR ? s{ BU j {st `B s sK ts 1( j 8skB R{B }$? Bt 8s $tB 1d R? sAsjB sj 11 js 8skB jst BR s 1n j 8skB 8BjZR{BU j {sjs8s $ st 1; s% R Z9 1x jBR } $8 BR n1 8 BR I j 8skB B st$R8B {BtB{$IB js R {Bks $ st RZ} }Z R BR s Zt sj { I n( 8 BR
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
$ 8}B s ? sR YsA? s RZP $IB t {s t } B}$s jsR I %sR sIB sR {BtR {Z t{$sR I IBR -}jBR$Bt R tZ{j s R ej s Z8 t B I js } $8 s } j? {Zjs
Fs}? Bt As`B j B I j 8BtR ZB
JZ R
} $ ? s YsR s js Rs{$ IsI t jsR }BR $B R t sR I js R $ R j R$ Z$ t U ZtsR } Z AsR tZ{j s R t j _s{? h{B I R}$ st I RZ j s B 8$j ts $B s js { $s Z s JZ s{ B R Z$IB R I I${s s I R Z$ BIB jB JZ R $t }Bt t RZ {s8$tB jj stIB YsR s jsR 8$R8sR {sjj R I qB,$B _B j 8B8 t B RBt dx jsR } j? {ZjsR JZ PB 8st }s I R s Rs s sZtJZ t RZ sP? st }B {${js jsR Pst sR? sR k 8$ BR I R$ 8} <BjjkbBBI s{sAs I {Z} s jsR stIst9sR I j $ st `s}Bt? R s8A$ t ? stIBjsR RB R? t eR sIBR =t$IBR wpBI9$jjs >d MHD _ R s RZR I R} B}? BR$ BR jsR } $8 sR } j? {ZjsR }BR t Zt $t tZB t{st B wpBI9$jjs R Zt s{ B {ZA$ B {Bt Zt I$RP s9 I {sZ{YB 8B%$? tIBR }B Zt I {B sIBD JZ R Ys $IB I$PZ8$tstIB t Ps%B I Zts I R{s sIs -}jB s{$? Bt {B8 {$sj I jBR } B}$BR } RBts` R { sIBR eR sR } j? {ZjsR RBt Zts 8Z R s } R t s $%s I jsR
8BtR 8B%$ R
} j? {ZjsR {Bt 8BtR ZB
jsR I tB8$tsIsR
IBtI R Ist {$ s BIsR jsR {B8A$ts{$Bt R $8s $tsAj R eR P? s{$j t{Bt s
t R BR hj8 R 8BtR ZBR JZ {B8B j 8$R8B pBI9$jjs RBA }sRst {Bt YBj Z s jBR d(( 8 I s8sK tB 8B%$? tIBR R$t I$h{Zj sI R k jZ{YstIB s ? $j8 t t R? t 8 I$B I jBR s B $9sIBR YsA$ st R I qB,$B NBR s8$ BR k t 8$ BR I js { $s Z s R ? st 8? sR sjj? s I BIs I ht${$? Bt et{Bt s8BR s pBI9$jjs tP t ? stIBR s B BR {Bj sRT8BtR ZBR {B8B j 8$R8B $t Bt t $t Bt qs$ pB`$ s >d E1H B Y s Zts }Bj$jjs $ st @ t pB`$ s qs$ B Y s >d E;H isIBt Zt } BI? s{ $jB $ st t
*s$,s$`Z ps8 s
isIBt
>d xEH O ps8 s Zts $ st R{s B Z s } Y$R ? B ${s t
>d EEH w %$R$ sIs {$ t 8 t
ps8 s
>d HD
! A$ t t sj$st9s }s s
I P tI js q$ s I B BR 8BtR ZBR {B8B Zt R{s sAs`B $ st t >d nH B Zts R} {$ I BAB {Bt BjsIB }B sj$ t? tsR s}B BR$R htsj js {BtR $ Zk Zt }s $ t Z B} B
s$`Z 7BRY$t T ,$
pB`$ s qs$ s Bt pB`$ s qs$ s B`$ s >d ;H Ns
>d EMH {Bt js }Z R s t R{ ts R$8Zj ? st s I
Bt{ 8BtR ZBR 8s {s I js Ps{ B ? s `s}Bt Rs qBYB }sI I js { $s Z s V pBI9$jjs j RZ $? B
pB B
>d EdH B $ $ts $B I js $Rjs I Ws s t y jstIs JZ R 8A s ? s j
}? st${B t j NBtI R I jBR sK tBR E( 5<sk JZ$? t I? 8? sR2
d 1
Ns P? R${s I pZjj$% U $ st R k tstBR NBR %$s` R I pZjj$% I R{ $A jBR %$s` R $8s $ts $BR
ej j$A B I FBts Yst 7b$P wdEE Td ;xD
I N 8Z j pZjj$% et ZtB I jjBR R ts st jsR } $} {$sR s{Bt {$IsR t j $tB I N$j$}Z ? ABj RD RBt st? sjB BR s jBR I tZ R B 8ZtIB IBtI BIBR jBR R R %$%BR wYB8A R st$8sj R s } B IZ{$IBR t Zt Ps{ B I R{sjs d1 wZts }Zj sIs }B }$ D R I {$ RBt ZtsR IB{ % { R 8? sR } JZ K tBR NBR j$j$}Z $ tR R $ t t Zts R s Z s I ZtBR dx {8 }B ? 8$tB 8 I$B k RBt ZtsR ${sRD I tBRB BR ej $t ? }$IB %$s` B pZjj$% %$R$ s s8A$? t j $tB ? }j${sR s R{sjs w$RB8? I BAI$t ts j }s? R I jBR $ st R IBtI BIB R ? s s8}j$sIB IB{ % { R wPs{ B I R{sjs d1D ej j$A B I 7b$P R Zts I j${$BRs R? s $ s I js %$Is I js ? }B{s j R$ jB zyyy sRjsIsIs s R BR 8ZtIBR $8s $ts $BR _ B t$ jBR I$8$tZ BR j$j$}Z $ tR R t$ jBR $ st R A BAI$t ts Z$stBR }BI ? st sj8 t -$R $ sj {B8B ? j jBR I R{ $A U "V }B{B R t ? JZ sj B %$%B R 8B%? s RBA
]B8B R {B8 t s t js } j? {Zjs j $ st R{B YZ %B I B Y s I IBtI RsjI ? st IBR js %sR {BjBRsj R $ t Zt s8sK tB JZ$%sj t sj I dxn M(( YZ %BR I sjj$ts wAsR st $tP $B s jB JZ jsR $8? s t R RZ $ tD 57 $8s $tst JZ? sRB8A BRs B $jjs2 @
© Los autores, 2001; © Edicions UPC, 2001.
n(
* $t Bt s e$tR $t
3$ d ; w8TT )ID =t $t{B8} tI$IB k ts8B sI$9B $t Bt tP t ? stIBR s jBR $t Bj st R YZ8stBR JZ tB s{ } st s $tI$%$IZBR {Bt sR BR I$P t R s js tB 8sj$IsI w8)I<*D _B RZ sjjs j k I jBR 8BtR ZBR I h{{$? BtU j $8} R$Btst pBI9$jjs Ys{$ tIB I jsR RZksR }B jsR {sjj R I qB,$B
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
nd
8$ }$ ts $9JZ$ Is k JZ s%st9stIB RZs% 8 t RBA 8$ } {YB 8 jj sAs YsR s { {s I js As A$jjs I$ $ $ tIB jBR B`BR Ys{$s sAs`B {Zst B }ZI BAR %? JZ R s sAs I Zt R YZ8stB I 8 tBR I JZ$t{ { t ? 8 BR JZ s? s t jsR 8stBR Zt s {B {Bt Zts 4 {Ys " Z{YB st R JZ 7b$P psj$j B ks YsA? s {B8} tI$IB JZ jBR 8BI jBR s8}j$sIBR B IZ{$IBR I YB8A R tB }BI? st R {B8B tBRB BR eR{ $A psj$j BU "7$ R JZ$R$ s 8st t t Zt $ st js 8$R8s } B}B {$? Bt I 8$ 8A BR I Zt YB8A tB 8sj B A$ t R ? s t { Rs $B Z $j$9s Zt 8s $sj 8? sR IZ B k PZ }s s PB 8s jBR YZ RBR B A$ t I A ? s sI8$ $ R Zts I$R8$tZ{$? Bt I RZ R$R t{$s t {B8}s s{$? Bt {Bt js I Zt YB8A I R s Z s 8 I$sU }B JZ R$ R sZ8 t sR I R} B}B {$BtsIs8 t js R s Z s {s ? s k JZ Is ? s s}jsR sIB }B RZ } B}$B } RB et {s8A$B R$ R I$R8$tZk j s8sK tB I Zt {Z }B RZ R$R t{$s tB I$R8$tZk t js 8$R8s } B}B {$? Bt t sj$IsI {Zst B 8? sR } JZ K tB R s j {Z }B st B 8? sR stI R ? s RZ R$R t{$s js $%s VR? Zt } B }BI ? s } BAsAj 8 t jj %s RBA RZ jB8B s IBR B R } BR I RZ 8$R8B s8sK tB t {s8A$B tB { B JZ Zt {sAsjjB }Z Is jj %s RBA R? t$ st RBjB s B B {sAsjjB "
<B8A R sRB8A BRs8 t {BjBRsj R ej {Z }B YZ8stB B j I Zt st$8sj }Z I sR$8$js R s Zt {Bt`Zt B I {BjZ8tsR k }Zt sj R j RJZ j B RB}B sIB }B I$% RBR {sAj R jBR 8? ZR{ZjBR k jBR tIBt R ej } RB JZ j {Z }B I A RBR t R } B}B {$Btsj s js {st $IsI I {s t k YZ RBR } R t R I {$ sj %BjZ8 t B sj {ZAB I Zts jBt $ ZI {s s{ ? R ${s wjs sj Z s }B ` 8}jBD 7$ {B8}s s8BR jsR PZ 9sR js $%sR I pZjj$% k I j $ st I BAI$t ts JZ R d1 % { R 8? sR sj B BA t 8BR JZ j $ st }BR Zts PZ 9s js $%s d1 % { R $tP $B s js I pZjj$% eR B R$ t$h{s JZ j } RB JZ j $ st RB}B s R JZ$%sj t sj JZ I A ? s s Zst s Zt YB8A {B8B pZjj$% {Bt gd1 YB8A R 8? sR t{$8s 7$ } tRs8BR JZ Zt YZ RB P? 8Z YZ8stB R B8} As`B Zt } RB I I$ 9 % { R j I Zt YB8A tBR Is 8BR {Z t s tR Z$Is JZ sj {B8B RZ{ I? s t j {sRB I jBR $tR { BR $ st R B I j 8$R8B $t Bt R sR { $s Z sR {BjBRsj R R ? st j$ sj8 t s}jsR sIsR }B RZ } B}$B } RB WB }s { }Z R JZ j {B Bt j stt$t j YZ8stB -}Z R B s{{$I t sj8 t s js sI$s{$? Bt s ? B8${s JZ { { s Zt $ 8B I d x 8 I$s $BR k R {Bt%$ t ej $ st s s{s >qY V8s9$t ]BjBRRsj st d x H Zt $ st I 8? sR I dM8 I s8sK tB t s I 8sR$sIsR }BR$A$j$IsI R }s s % t{ s jsR $t -B sAj R j k R I R{sjs qs8}B{B js ? }j${s P 8 t$ts I R RB } tI t R } B s Bt$R s I js } j? {Zjs ej s sJZ I js 8Z` I dx 8 >V s{, BP Y x( P GB8st d xMH {Zks {$ t % R$? Bt Is s I d ; $ t %$RBR I sj$IsI }B 8Z{YB JZ j $ st $R8B I R s R K tB s R s{YsJZ sj t{Z t B {Bt Zt B%t$ ,
7$ Z$ tIB {Bt js $I s I R BR Y$}B ? ${BR $ st R $8s $t 8BR sYB s {? B8B R ? s RZ s}s $ t{$s P? R${s 7Z}Bt s8BR JZ jsR 8 `$jjsR I Zt YZ8stB } R t st Zts RZ} h{$ I ZtBR 1x {81 k $ t t d{8 I BRB ]Bt Zts I tR$IsI tB 8Z{YB 8skB JZ js I j s Zs js 8sRs I jsR 8 `$jjsR RZj s R I ZtBR 1x et {B8}s s{$? Bt js 8sRs I jsR 8 `$jjsR I Zt A BAI$t ts Z$stB R ? s d1n % { R RZ} $B R I {$ I ZtBR ;n, V {sZRs I js Psj s I $ $I 9 I js {s t k s R}st BRs WB R ? s R} {$sj8 t I js sRs js {s s wk j {Z }BD I tZ R B $ st R ? Zt }s ? Bt I R ? ${s JZ I$ s8BR g_B jB 8 tBR tB R ? s jB JZ tZ R s RB{$ IsI {BtR$I s {B8B s s{ $%B WsIs JZ % {Bt jB JZ tBR $tIZ{ s { j {s j }ZAj${$ s $B I js } j? {Zjs ej s sJZ I js 8Z` I x( }$ R 5+Z? JZ Is ? s I RsR B ZtIsR k Z t R PB 8sR I js R K tB s B $ $tsj Zts % 9 {Bt% $Is t $ st 2
© Los autores, 2001; © Edicions UPC, 2001.
n1
* $t Bt s e$tR $t
_Z R BR s - s}Bjs jsR {BRsR }BI ? s8BR sI8$ $ } R s RZ P sjIsI JZ jBR $ st R R ? st R R 8Zk $t j$ t R 7 ? Zt }s { js {s}s{$IsI 8 t sj I Zt YB8A $ t JZ % tB st B {Bt j } RB I j { A B {B8B {Bt js RZ} h{$ I j 8$R8B 7$ t } $8 s s} B-$8s{$? Bt RZ}Bt 8BR JZ js {s}s{$IsI 8 t sj R } B}B {$Btsj sj {ZsI sIB I Zts jBt $ ZI {s s{ ? R ${s t Bt{ R js $t j$ t{$s I R BR $ st R R ? s 8st$h R s8 t RZ} $B s js I jBR YZ8stBR tB 8sj R qsj % 9 R B tBR } 8$ s -}j${s js $t j$ t{$s {Bt JZ jBR Z$Bt$R sR I js } j? {Zjs Yst IB sIB sj B $js $t Bt VZtJZ I }B{B }Z I R %$ j R s R BR $ st R RZ $t j$ t{$s R$ tB }Z I t {Zj $%s js {Bt }B ` 8}jB js j { Z s I j$A BR O R$ tB % st jsR I$h{Zj sI R I j R K tB stt$t j sRB8A BRB YB8A {BjBRsj {ZstIB $t t s j Zt j$A B JZ tB R 8skB JZ RZ }Zj s U j s8sK tB I jsR j sR RZj s }s s ? j st I$8$tZ B JZ t$ PB 9stIB js %$R s }Z I jj s s I R{$P s jsR 7 ? s t {B8}s s{$? Bt {B8B $t t s j Zt j$A B t 8$t$s Z s {ZksR j sR 8$I$ st Zts I? {$8s I 8$j? 8 B t jZ s I jBR d B 1 8$j? 8 BR tB 8sj R * BIsR PB 8sR jBR $ st R I A ? st Ys{ P t sI 8? sR s B BR 8Z{YBR } BAj 8sR I $}B hR$Bj? B ${B V? Zt t j {sRB I tB 8B $ }B j s}jsR s8$ t B I RZ } B}$B } RB js sRh-$s B Zts $tRZh{$ t{$s tsj s{sAs ? st {Bt RZ %$Is $ t sR JZ js {st $IsI I `$IB { jZjs {Bt t { R$IsI I B-? tB { { {Bt j {ZAB I js jBt $ ZI s 8 I$Is JZ R sZ8 t s I s8sK tB js {s}s{$IsI I sARB {$? Bt }B }s I jBR }Zj8Bt R R } B}B {$Btsj s js RZ} h{$ I jBR 8$R8BR k }B st B sj {ZsI sIB I js jBt $ ZI NsR t { R$IsI R %$ sj R I B-? tB I j B st$R8B tB R ? st Rs $RP {YsR k R } BIZ{$ ? s js 8Z }B sRh-$s =t s9Bts8$ t B R$8$js R s}j${sAj s jBR $K tBt R JZ s{ ? Zst {B8B hj BR Rst Z? t BR Ns {s}s{$IsI I hj sIB I j $K tB ?t I } tI I js jBt $ ZI k I js RZ} h{$ I RZ R Z{ Z s ZAZjs 8$ t sR JZ j %BjZ8 t I Rst R } B}B {$Btsj sj {ZAB I j s8sK tB Nj sIBR s R }Zt B }BI 8BR } Zt s tBR {Z? sj R ? s js sj Z s 8? s-$8s JZ }Z I jj s s t Zt YB8A z s8BR {? B8B jsR j k R I R{sjs tBR } 8$ t t{Bt s Zts {B s RZ} $B 7Z}Bt s8BR JZ js sjjs 8? s-$8s I Zt $tI$%$IZB %$ t j$8$ sIs }B RZ {s}s{$IsI }s s j %st s jsR }$ tsR I j RZ jB =t $ st I s8sK tB 8skB tB }BI ? s sj$9s R s R t{$jjs B} s{$? Bt k }B st B }BI 8BR } RZ}Bt JZ tB R ? s Zt R %$sAj ej } RB I jsR }$ tsR } R t s sj I IB I Zt dx0 I j } RB {B }B sj Ns PZ 9s js $%s I j $ st {s}s9 I j %st s sj 8 tBR R } RB R ? s (, dx 7$ sIB} s8BR Zt %sjB 8? t$8B I (, x }s s Zt YB8A j s8sK tB I j $ st R ? s t Bt{ R (, xb(, dx % { R js sj Z s I Zt YB8A w {B I 8BR JZ js PZ 9s }Z R BA t 8BR }s s j $ st Zt js $%s R $t% Rs8 t } B}B {$Btsj sj s8sK tBD VR? sj Z s 8? s-$8s I ZtBR E 8 YsA$ tIB {BtR$I sIB Zts sj Z s I d, M( 8 }s s j YB8A 7$ {BtR$I s8BR Zt %sjB 8? sR j %sIB }s s js PZ 9s js $%s I Zt YB8A d }B ` 8}jB t Bt{ R js sj Z s 8? s-$8s I j $ st R R$ Zs ? s sj I IB I jBR d1 8 zsjB ? B ${s8 t }BR$Aj } B 8Zk sj `sIB I jBR 1, ( 8 JZ 8 I? s iBA GsIjBb j YB8A 8? sR sj B JZ Ys -$R $IB I j {Zsj JZ Is {BtR st{$s w3$ d xD ]Bt R BR R$8}j R s Z8 t BR I$8 tR$Btsj R }BI 8BR {Z R $Bts js sj$IsI P? R${s I js 8skB ? s I RBR R R {BjBRsj R {$ {ZtR{ $A$? tIBjBR s js sj ? s I 8$ BR I j { jZjB$I R$t t$t ? Zt k tZt{s 8 `B I${YB RBR ? t sj q sR jB JZ s{sAs8BR I I {$ 5}BI ? s8BR jj s s js {Bt{jZR$? Bt I JZ }B ` 8}jB jBR {BjBRBR I q$ s I $ st R Zts Ps8BRs R $ I qz I jBR sK tBR R R t s R s ? st s sR ? stIBR }B j RZ jB R$ tB 8Z BR }B s}jsR s8$ t B2 WB t { Rs $s8 t 7$ {B8B -}j${s yRss{ VR$8B%
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
nn
3$ d x iBA GsIjBb 8 I? s 1, ( 8 s js IsI I % $t sK tBR 7Z }sI JZ s}s { s RZ jsIB t js PB B sP? s t? s Zts sjjs I d, M( 8 =ts I$RPZt{$? Bt I js j? stIZjs }$ Z$ s $s }Z I sIZ{$ R t {sRBR I $ st $R8B {B8B ? R ej { {$8$ t B -s sIB R 8st$h R s I Zts PB 8s 8? sR {js s t js {sA 9s k t jsR }$ tsR wsIs} sIB I qs8sK tB k %$Is q V { sYBt k F q Btt d MED
© Los autores, 2001; © Edicions UPC, 2001.
n;
* $t Bt s e$tR $t
j Z$Bt$R s I js R $ PZ R Zt sZ B {B8} t I js BR I {$ t{$s h{{$? Bt sI% $ ? s s jBR j %$I t R JZ jBR YZ RBR I jBR $ st R RBt I s{ B B I {ZsjJZ$ B B 8s $sj R$R t JZ js s% IsI I j }jst s IBtI R I Rs Bjjs js s8s R $tP $B s js R B JZ RZR 8? ZR{ZjBR PZt{$Btst I 8st s I$P t s jBR tZ R BR ]js B R ? s JZ R B tB R {B8 t s tZt{s et j 8ZtIB I jBR R R stI R R I {$ I s8sK tB {B8}s sAj sj I Zt R YZ8stB js PZ 9s I js s% IsI j } RB R js R}BtRsAj I BIBR jBR P { BR {B8 t sIBR V tI$ tIB s jsR j k R I R{sjs R I R} s JZ jBR YsA$ st R I 8ZtIBR {Bt s% IsI R I$P t R s js R }BR st PB 8sR k s8sK tBR s8A$? t I$P t R e` 8}jBR $jZR s $%BR jBR t 8BR t jBR 8 R,j$t$ sR I js tB% js $R$? Bt I s% IsI > $RR$Bt BP p s%$ k d xnH I <sj ]j 8 t k t jBR {Y js I <Z %B I I s ? Bt >* s Bt:R e d M(H I iBA 3B bs I IBtI js j %sIs s% IsI I RZR }jst sR ts sj R $8}Bt JZ R st R R I } JZ K ts sjjs k I PB 8sR sjs sIsR k s}jstsIsR et NsR ts% R I j $ 8}B >qY q$8 7Y$}R d xH I 7 }Y t s- R I R{ $A js -$R t{$s I Zts s9s I R{ tI$ t I js YZ8sts jBR 8B jB{,R 1 YsA$ st R I j $t $B I Zts RP s I *kRBt t B s{$? Bt eR sR { $s Z sR YZ8stB$I R } R t st Zts R s Z s st B 8skB {Zst B 8? sR sj `sIsR R t{Z t st I j {ZsIB I js RP s IBtI js s% IsI R js $%s8 t ZjB nD 8? sR stI w]s}?
<B8A {$jjBR $t{ ? Aj 8 t 8 t ZsIBR _ R sj jBsAj BA` $%B JZ st$8s js -} I${$? Bt I j JZ$}B JZ 8} tI Zt Pst ? sR ${B %$s` }B j $t $B I j {Z }B YZ8stB t j hj8 z$s` sjZ{$tst >3st sR ${ zBks d EEH B j 8 tBR $t{BtP RsAj I j {$ t ? h{B JZ IZ{ s 8 I$s IB{ ts I YB8A R k 8Z` R }s s t {B8}sK t? s YZ8sts I ABjR$jjB t V s{, BP Y _Z}} _ B}j >d xMH js IZ{{$? Bt YsR s s8sK tBR } JZ K tBR R}j? tI$Is8 t $jZR sIs t R BR hj8 R }jst s tZ %BR } BAj 8sR z s8BR s {Bt $tZs{$? Bt sj ZtBR I jjBR t ${B s tBRB BR sZtJZ I Zt s8sK tB d1 % { R ]ZstIB Zt j$j$}Z $ tR w {B I 8BR Zt R $I? tB ? B t JZ s{sAs I Is R Zt AsK tB jj %s sIY $Is RBA RZ }$ j Zts $tP $B D Rsj I j } JZ K I j sIs } j? {Zjs I s Zs JZ }BI 8BR RZ}Bt Zt$PB 8 8 t }s $Is }B BIB RZ I$8$tZ B {Z }B et R sR 8$R8sR {BtI${$Bt R js {st $IsI I s Zs JZ Zt AsK t$R s I tZ R s sjjs - s }Z I R $8s R t Zt {Zs B I j$ B eR s 8sRs I s Zs } R t s sj I IB I Zt (!x0 I j } RB I j {Z }B _s s j j$j$}Z $ tR t {s8A$B js {st $IsI I s Zs - s? Is } B}B {$Btsj s 1 RZ RZ} h{$ {B }B sj R d1 % { R $tP $B 8$ t sR JZ j } RB I RZ {Z }B R Ys IZ{$IB t Zt Ps{ B d1n t js{$? Bt sj I j YZ8stB I sjjs tB 8sj eRs 8 tB {st $IsI I s Zs } R t s tB BAR st }s s ? j Zt E0 I RZ } RB eR {B8B R$ {sIs % 9 JZ Rsj$8BR I j s Zs jj %? sR 8BR t{$8s j JZ$%sj t t s Zs sj } RB I js B}s I sA $ B $t% tsj wsA $ B ` R kR AB sR D 57 ? st t Bt{ R tZ R BR 8B%$8$ t BR st s ? $j R2 5WB 8} 9s ? s8BR s t {$ sR I$h{Zj sI R }s s 8B% jsR s ${Zjs{$Bt R2 3$`? 8BtBR t js 8BR{s JZ $t{sZ s8 t {s t Zts s9s jj ts I {sP? ]ZstIB R js - s I js 8$R8s Zts R$8}j B s I j? JZ$IB R RZh{$ t }s s 8st t s} $R$BtsIB sj $tR { B
7 R JZ ks s}s {? st t js tB% js I < A p G jjR Ns 8? sJZ$ts I j $ 8}B >qY q$8 s{Y$t dM xH k I js {Zsj js tB% js I s- } tI R Zts {Bt $tZs{$? Bt
1
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
nN
3$ d E =ts 8st s I sZ8 t s js 8sRs I j {Z }B t {Z R $? Bt R$t {Z $ s 8s $sj R I$P t R I R$R t{$s 8skB U {s8A$s jsR } B}B {$Bt R s 8 I$Is JZ { { j s8sK tB B I tstIB j 8s $sj I Zts PB 8s 8? sR P { $%s _B ` 8}jB {ZstIB R {B8}s st st$8sj R I I$P t R s8sK tBR I Zts 8$R8s R} {$ R BAR %s JZ js jBt $ ZI k j BRB I jBR YZ RBR tB sZ8 t s I 8st s } B}B {$BtsjU sj sZ8 t s j s8sK tB js st{YZ s I jBR YZ RBR I jsR }s sR { { t 8skB } B}B {$? Bt JZ js jBt $ ZI NBR YZ RBR I jBR st$8sj R I 8skB R I$8 tR$Bt R RBt 8? sR Z RBR k {B8}s s $%s8 t 8 tBR js BR JZ jBR I jBR st$8sj R } JZ K tBR Y {YB ? R ks s}Zt sIB }B j } B}$B psj$j B 7$ I R s8BR R Z$ } tRstIB t js -$R t{$s I $ st R tB tI 8BR 8? sR 8 I$B JZ 8} 9s s AZR{s R R {Bt Zts s}s $ t{$s {B8B j I js h Z sU Zt $ st YZ8stB I d( Bt jsIsR I } RB I$R K tsIB 8st t$ tIB j 8s t I R Z $IsI }s s js } R$? Bt RBA jBR YZ RBR I RZ RJZ j B st I YsA R sIB ej $ st $ t Zts R s Z s 8? sR Bj sAj I n 8 w t jZ s I jBR d( 8 JZ j {B R}BtI ? R{sjsIB } B}B {$Btsj8 t D Zts st{YZ s I ZtBR x 8 k ZtBR 1, x 8 I } BPZtI$IsI 7 sR 8 `s }B{B s Zts } RBts
© Los autores, 2001; © Edicions UPC, 2001.
n-
* $t Bt s e$tR $t
NsR t { R$IsI R sj$8 t ${$sR I Zts { $s Z s I Rst {sj$ t }Z I t I 8$ts R I PB 8s s} B-$8sIs t$ tIB t {Z t s j {sjB I R} tI$IB s s%? R I js }$ j w} BIZ{$IB }B jsR s{{$Bt R JZ? 8${sR JZ $ t t jZ s t j $t $B I j B st$R8BD JZ R } B}B {$Btsj s js RZ} h{$ I j {Z }B 7$ {B8B R K tsjs 7b$P Zt YB8A {B8B pZjj$% }Z I %$%$ ZtB B IBR I? sR {B8$? tIBR Zts }s s I {B I B k Zts YB s9s I }st 5{Z? sj R R ? st jsR t { R$IsI R I sj$8 t B I Zt j$j$}Z $ tR 2 NBR YB8A {$jjBR I j $tB I N$j$}Z $ t t Zts RZ} h{$ {B }B sj t d;; d11 % { R $tP $B s js I pZjj$% 7ZR JZ $8$ t BR sj$8 t ${$BR RBt }B st B s8A$? % { R 8 tB R _ B BIB t RZ 8ZtIB R ? s IZ{$IB t Zt Ps{ B d1 I 8st s JZ jsR }s sR I {B I B k jsR YB s9sR I }st I N$j$}Z $ t t Zt %BjZ8 t d1n % { R $tP $B * A ? st {B8 R }Z R Zts IB{ ts I {sIs R$ I R st R s st A$ t sj$8 t sIBR {B8B pZjj$% gy8s ? t tR sj$9s d1 {B8$IsR I$s $sR NBR j$j$}Z $ tR R }B st B I A ? st R R R $tJZ$ BR s s sIBR st B t js A? ZRJZ Is I sj$8 t BR {B8B t RZ } }s s{$? Bt }s s js } ? B-$8s $t R s sZtJZ {Bt Zts tB sAj Ps{$j$IsI I } { sYB sIBR t j s Zs ]s s{ ? R ${sR JZ } R t st 8Z{YBR 8s8? P BR } JZ K tBR {B8B }B ` 8}jB jBR s Bt R !AR % 8BR {? B8B t js ts Z sj 9s tB -$R t st$8sj R I Rst {sj$ t 8Z{YB 8? sR } JZ K tBR JZ j s ? Bt W { R$ st Zts st {st $IsI I sj$8 t B t {B8}s s{$? Bt {Bt RZ } RB k R B $8}Bt PZ R R ${{$Bt R et js{$? Bt {Bt RZ } RB Zt st$8sj stI {BtRZ8 8 tBR sj$8 t BR JZ ZtB } JZ K tB =t YB8A P B 8? sR } JZ K tB js 8ZRs sK ts $t $ dbx( I RZ } RB }s $IB t R {B8$IsR I$s $sR ej 8s8? tsts {Bt Zt } RB JZ tB RBA }sRs jBR 1, x {B8 {Bt $tZs8 t Zts {st $IsI I sj$8 t B $ Zsj s ZtsR {Zst sR % { R RZ } RB ej R YZ8stB I R s Z s 8? sR } JZ K ts _sZj$t ZR R 8 I? s n( {8 t j 8B8 t B I RZ B s jBR d sK tBRD { {$? B RBjs8 t nd {8 7Z sjjs ts{$8$ t B *Z st RZ {B s %$Is w8Z $? I sIZj s PZ I Ed {8 e-{ } B t {sRBR - 8BR k s BR {B8B ? R j s8sK tB I j YB8A tB }Z I R s8}B{B 8Z{YB 8? sR } JZ K tB JZ js sjjs tB 8sj e-$R t st$8sj R I s8sK tB $tP $B } B tB RBt R 8 `st R sj YB8A * js 8$R8s 8st s JZ Zt YB8A sZ8 t sIB YsR s ZtBR {Zst BR 8 BR R ? s {B8B Y 8BR R K tsjsIB 8Zk P ? s $j k {Bt Zts PZ 9s js $%s } JZ K ts Zt YB8A IZ{$IB YsR s sj ZtsR I { tsR I { t ? 8 BR R ? s I 8sR$sIB BAZR B k RZ} 8ZR{ZjsIB ]ZstIB 7{B ]s k R $tP { sIB }B Zts - sK ts tZA k 8}$ 9s s I$R8$tZ$ I s8sK tB I PB 8s j t s } B $t -B sAj {Bt%$ $? tIBR t ej $t{ ? Aj YB8A 8 t Zst >qY yt{ I$Aj 7Y $t,$t st d x H k sj{st9s Zts R s Z s I sj ZtBR }B{BR I {? 8 BR RZR 8? ZR{ZjBR I A ? st s{sAs }B I R B9s RZ } B}$B {Z }B VZtJZ st R R Z s8 t B BR } BAj 8sR hR$Bj? B ${BR YsA ? st IsIB ks AZ ts {Z t s I ? j i IZ{$IB t Zt Ps{ B I R{sjs (, d j %BjZ8 t I RZ {Z }B R ? s d3((( % { R $tP $B 8$ t sR JZ js RZ} h{$ I RZR }Zj8Bt R j R ? B8s B js R {{$? Bt I jsR s $sR { YsA ? s I$R8$tZ$IB R? BjB d(( % { R ej $ 8B 8 sA? Bj${B I RZ {Z }B R ? s d( % { R RZ} $B sj tB 8sj ]Bt BIs } BAsA$j$IsI j -{ RB I {sjB } BIZ{$IB jB {BtIZ{$ ? s s js 8Z VZtJZ s % { R R } JZ K tB }Z I t {$ sR % t s`sR Vtsj${ 8BR js R$ Z$ t P sR I j stR js P? R${s RZAks{ t k tB $t t t } $ j -} $8 t BDU hR$? BjB B FBYt 7 <sjIst w{ ? "7$ R I `s {s Zt s ? Bt t j $t $B I Zt }B9B I d(( 8 I } BPZtI$IsI {ZstIB jj s sj PBtIB s} tsR RZP Zts j$ s {Bt ZR$? Bt k R{s}s =ts s s } BAsAj 8 t 8B $ ? s t js {s? Is sZtJZ RsjI ? s $j Rs sR {s I Zt ZtI? {$8B }$RB Zt YB8A } { ? s R$t IZIs sj Zts k Zt {sAsjjB RZj s ? s s}jsR sIB }B j $8}s{ B" =t BA` B t {s? Is j$A t Zt 4Z$IB {B8B j
© Los autores, 2001; © Edicions UPC, 2001.
d Â&#x20AC;$t Â&#x20AC;Bt YB8AÂ&#x201E;Â&#x201A;R 8Â&#x201A;t Zst Â&#x201A;R k Zt$%Â&#x201A;Â&#x201E;RBR Â&#x201A;t Zts B s IÂ&#x201A; s Zs
n
3$ d wVÂ&#x201E;Â&#x201E;$AsD ej I$8$tZ B }Â&#x201E;B s Bt$R s IÂ&#x201A; ej $t{Â&#x201E;Â&#x201A;? AjÂ&#x201A; YB8AÂ&#x201E;Â&#x201A; 8Â&#x201A;t Zst Â&#x201A; >qYÂ&#x201A; yt{Â&#x201E;Â&#x201A;I$AjÂ&#x201A; 7YÂ&#x201E;$t,$t st d x H jZ{YstIB }BÂ&#x201E; RZ RZ}Â&#x201A;Â&#x201E;%$%Â&#x201A;t{$s {Bt Zts sÂ&#x201E;sK ts wVAs`BD _sZj$tÂ&#x201A; ZR Â&#x201A;Â&#x201E;R {Bt sj ZÂ&#x201E;s IÂ&#x201A; Ed {8 s Zts Â&#x201A;IsI sIZj s Â&#x201A;R Â&#x201A;j RÂ&#x201A;Â&#x201E; YZ8stB IÂ&#x201A; sjjs 8? sR }Â&#x201A;JZÂ&#x201A;K ts IÂ&#x201A;j {Zsj RÂ&#x201A; $Â&#x201A;tÂ&#x201A; {BtR st{$s
Š Los autores, 2001; Š Edicions UPC, 2001.
nM
* $t Bt s e$tR $t
s$ sj{st9s js % jB{$IsI j? 8$ {ZstIB RZ } RB $ Zsjs s js PZ 9s I R$R t{$s JZ B}Bt j s$ sj s%st{ I j 8$R8B eR s R$R t{$s I } tI }s s } JZ K tsR % jB{$IsI R I js RZ} h{$ I j {Z }B k I RZ % jB{$IsI R} { B I j 4Z$IB * 8st s JZ {B8B j } RB R I$ { s8 t } B}B {$Btsj s js 8sRs k }B st B sj %BjZ8 t I j {Z }B RZj s JZ js % jB{$IsI j? 8$ R } B}B {$Btsj sj s8sK tB ]Zst B 8 tB R s j BA` B st B 8 tB R ? s js % jB{$IsI {Bt js JZ ? R s $9s ? s t j RZ jB WB Ysk tsIs {B8B R } JZ K tB }s s RBA %$%$ s jsR {s? IsR _ B jB $ t t t {s8A$B jBR YB8A {$jjBR IZ{$IBR I js } j? {Zjs * ]k{jB}R >d ;(H AsRsIs t j js B *B{ B ]? {jB} >* ]k{jB}R d ;(H I < t k Z t R$ } tI t RBA %$%$ sj {Bt ZtI t B{ RB I j s 8s JZ R s} R st s I$R}s s R ? Zt }Z I % R t js h Z s d M i RZj s P? s{$j %sjZs js % jB{$IsI I B{ RB JZ -} $8 t s ? s j PZR$j Zts % 9 I$R}s sIB ks JZ }s s j R$R 8s {BtR $ Z$IB }B j PZR$j k js Asjs }Z I s}j${s R j } $t{$}$B I {BtR %s{$? Bt I js {st $IsI I 8B%$8$ t B w t sZR t{$s I PZ 9sR - $B R j } BIZ{ B I jsR 8sRsR I jBR BA` BR }B RZR % jB{$IsI R } 8st { {BtR st D _s s Zt PZR$j I ; , k Zts Asjs I 1( JZ R $8}ZjRsIs s ZtBR n(( 8bR RZj s Zts % jB{$IsI I B{ RB I d, x 8bR ej P { B RBA js } RBts JZ jB I$R}s s I } tI I js 8sRs I js 8$R8s k I j $}B I {Bj$R$? Bt JZ -} $8 t {Bt I${Ys s 8s 7$ js 8sRs I jBR YZ8stBR IZ{$IBR Ys I$R8$tZ$IB } B}B {$Btsj8 t s Bt I d1 js sjjs I jBR 8$R8BR R ? s I ZtBR RZ s8sK tB w}s s Zt Ps{ B I R{sjs I IZ{{$? dx { t ? 8 BR 8$ t sR JZ RZ 8sRs R ? s I ZtBR ;( s8BRD j $8}s{ B {$A$IB }B jBR YB8A {$jjBR }BI ? s R 8B sj qsj % 9 s{sAs ? st {Bt j 8sj%sIB IB{ B qYB , j {sZRst I RZ R sIB s{ Zsj } B R ? s s {BR s I RZ } B}$s %$Is
*$? sjB BR t $ st R k tstBR Ns %$R$ s I j sZIs9 %$s` B pZjj$% s jBR $tBR I N$j$}Z k BAI$t ts }jst s s8A$? t } BAj 8sR P t R s js {B8Zt${s{$? Bt NsR {Bt% Rs{$Bt R t pZjj$% k jBR R? ZAI$ BR I R BR $tBR tB }BI ? st P { Zs R 8 I$st j YsAjs NsR {Z IsR %B{sj R I jBR st$8sj R $t{jZ$IB j YB8A RBt } JZ K tBR 8? ZR{ZjBR {Zks tR$? Bt }Z I %s $s R s %BjZt sI Vj sA $ R B { s R }s {$sj8 t } BIZ{ t jsR %$A s{$Bt R I j s$ JZ Ist jZ s sj YsAjs B s js 8$R$? Bt I RBt$IBR et } $8 s s} B-$8s{$? Bt }Z I t sR$8$js R s Zts {Z Is I Zts jBt $ ZI I 8$tsIs RB8 $Is s Zts {$ s tR$? Bt =ts % 9 h`sIs js tR$? Bt k js I tR$IsI I js {Z Is js P {Z t{$s I %$A s{$? Bt I js 8$R8s JZ R $ Zsj s js I j s$ JZ js BI s RZj s R $t% Rs8 t ? } B}B {$Btsj sj {ZsI sIB I RZ jBt $ ZI eR s R ? s js{$BtsIs {Bt Zts jBt $ ZI {s s{ ? R ${s {B8B }B ` 8}jB j s8sK tB I j st$8sj _ R s js R t{$jj 9 I R 8BI jB jsR P {Z t{$sR JZ R BA $ t t {Bt{Z Ist I 8st s {Zsj$ s $%s {Bt js I jBR RBt$IBR 8$ $IBR }B AZ ts }s I jBR st$8sj R 7 Ys BAR %sIB JZ {Zst B 8skB R j st$8sj st B 8? sR s% RZj s R RZ %B9 et j YsAjs YZ8sts js s st s k jsR {s%$IsI R AZ{sj k tsRsj s{ ? Zst {B8B R Z{ Z sR RBtst R JZ R t{s st I Rsj s ZtsR P {Z t{$sR k I s tZs B sR IstIB jZ s s Zts tB sAj %s $ IsI I RBt$IBR Ns P {Z t{$s PZtIs8 t sj I js %B9 YZ8sts R I ZtBR dx( <9 t j YB8A k I 1x( <9 t js 8Z` 7 ? Zt R BR RZj sIBR 5{Z? sj R R ? st jBR } BAj 8sR I {B8Zt${s{$? Bt -$R t R t pZjj$% k jBR I$8$tZ BR j$j$}Z $ tR R2 7$ {B8}s s8BR jsR P {Z t{$sR PZtIs8 t sj R I jsR %B{ R I pZjj$% Zt YZ8stB tB 8sj k I Zt j$j$}Z $ tR sR } JZ K tB JZ pZjj$% D R ? Zt 7b$P Zt YB8A {$jjB I ZtBR dx { t ? 8 BR wd1 % { R 8? BA tI 8BR }s s ? R Z ?j $8B Zts P {Z t{$s PZtIs8 t sj I 8$R$? Bt I RBt$IBR d1 % { R
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
n
3$ d M et Zt jsAB s B $B R { B I j _ ? Z j IB{ B Vj -stI qYB , j -} B t t ? s s ? B8${s Z $j$9s Zt {BtI tRsIB I sI$B }s s {Bt% $ t 8$t? ZR{ZjBR tstBR s jBR {BjsAB sIB R JZ R YsA? st t sIB s }s ${$}s t RZR I$sA? Bj${BR } Bk { BR Bt$ s PB 8s I IZ{$ tZt{s 8 `B I${YB s jBR {Bt R s s $BR * js } j? {Zjs * ]k{jB}R >d ;(H
© Los autores, 2001; © Edicions UPC, 2001.
;(
* $t Bt s e$tR $t
RZ} $B s js I pZjj$% eR I {$ d1
$t %sjB I sZI$A$j$IsI I Zt YZ8stB {B8B pZjj$% ks JZ jsR P {Z t{$sR JZ j B? IB YZ8stB }Z I } {$A$ }s s Zt t$% j I $t tR$IsI I j RBt$IB RZh{$ t R R$ ? Zst t 1( k 1(!((( <9 i RZj s }Z R JZ R? BjB jBR st$8sj R I s8sK tB {B8}s sAj sj I j j$j$}Z $ tR {B8B s Bt{$jjBR }? s`s BR B 8Z {$? js BR R s ? st t I$R}BR${$? Bt I B? jB {ZstIB YsAjs ]js B JZ R B s8A$? t I } tI I js {s}s{$IsI sZI$ $%s k tB R? BjB I j s8sK tB ej 8$R8B P { B R } BIZ{$ ? s {ZstIB Zt $ st I j $tB I BAI$t ts $t t sR $t${$s
dx( <9 ) 1d E(( <9 !
eR s P {Z t{$s {s PZ s I j
Zts {Bt% Rs{$? Bt {Bt pZjj$% *sIB JZ j Ps{ B I R{sjs I s8}j$s{$? Bt R d1 R BR $ st R sR As`s JZ js I I ZtBR 1d 8 BR I sj Z s 8$ $ ? st RBt$IBR I Zts P {Z t{$s d1 % { R 8? Zt YB8A {B $ t {B8B pZjj$% sj I IB I d Y 9$B RZj stIB }B st B $tsZI$Aj R 7$ pZjj$% I {$I$ R I$ $ $ R s jsR Is8sR I N$j$}Z js R$ Zs{$? Bt j `BR I 8 `B s R % ? s 8} B sIsU jsR P {Z t{$sR I jBR RBt$IBR 8$ $IBR }B jsR j$j$}Z $ tR R R ? st s? Zt 8? sR sj sR JZ jsR I RZR {B8}sK t BR 8sR{Zj$tBR zB{ R I 8sR$sIB s ZIsR t Zt {sRB B I 8sR$sIB s% R t B B {B8B }s s RZj s sZI$Aj R }s s pZjj$% BI jBR 8? sR sj$R sR 8Z R st JZ t j } B{ RB I j YsAjs k I js sZI${$? Bt I jBR YZ8stBR $t %$ t t B sR P {Z t{$sR I tB8$tsIsR s 8? Bt${BR sI 8? sR I js P {Z t{$s PZtIs8 t sj 7$t 8As B jBR RZj sIBR BA t$IBR tB 8BI$h{st js {Bt{jZR$? Bt I JZ tB -$R t$t Zts }BR$A$j$IsI I {B8Zt${s{$? Bt B sj n t pZjj$% jBR tstBR I N$j$}Z k jBR $ st R I BAI$t ts et js } j? {Zjs
ej {Y$} } BI$ $BRB
>ytt R}s{ d M H j P { B stsj$9sIB R $ t t {Z t s s
8 I$sRU j {s8A$B I P {Z t{$s {Bt j s8sK tB RZj s s} {$sAj t jBR YZ8stBR IZ{$IBR s js 8$ sI I j s8sK tB tB 8sj jBR {Zsj R YsAjst {Bt Zts %B9 8? sR s ZIs WB R sR? t j {sRB I j YZ8stB IZ{$IB s Zts R{sjs 8${ BR{? B}${s ej 8B $%B R BA%$B * R sR? jBR R} { sIB R I j hj8 R ? st $t{s}s{ R I B? jB JZ I${ eR js 8$R8s j${ t{$s I Z$? Bt JZ {sA s $AZ$ s jBR %sj$ t R $}Zjst R I j 8${ BR{? B}${B RZA8s $tB
_ B ZR I z$s` sjZ{$tst U
RZR %B{ R {s ? st
PZ s I j st B JZ RB8BR {s}s{ R I R{Z{Ys w}B 8Zk RBhR ${sIBR JZ R st jBR P { BR I RBt$IB I js Rsjs I } Bk {{$? Bt I j hj8 D et sj$IsI js 8skB }s I js } j? {Zjs I A ? s R 8ZIs }s s jBR R} { sIB R YZ8stBR et js R{ ts htsj I js } j? {Zjs
Ns 8BR{s >qY 3jk d xMH
j t tI B {Bt js {sA 9s IZ{$Is I j {$ t ? h{B VtI ? * js8A k j {Z }B I 8BR{s }$I RB{B B {Bt Zt BtB I %B9 st sj B JZ s} tsR R j t $ tI qs8A$? t j t sj * {, {s8A$s RZ %s Bt$j %B9 }B B s 8? sR s ZIs sR R 8$t$s Z $9sIB }B jBR $8} ZBRBR sj$ t? tsR I
s R V s{,R
>d EH _BR$Aj 8 t tB R st jsR %B{ R JZ sj8 t I A ? st {B R}BtI j R s
tB I js I } tI t{$s t js P {Z t{$s k j s8sK tB stsj$9sIs st $B 8 t } B } 8$ $jZR s s js } P {{$? Bt j P t? B8 tB _B Zts % 9 jBR Z$Bt$R sR $ tI t s s`ZR s R s js sj$IsI ej P { B {Bt s $B I A ? s s} {$s R s8A$? t t j }B t BRB A s8$IB I Zt B $js $ st {B8B $t Bt 8Z{YB 8? sR s% I {B8B R tBR } R t s t js } j? {Zjs
* Y {YB t tZ R B 8ZtIB jBR $tR Z8 t BR 8ZR${sj R R {BtR Zk t I s8sK tBR I$P t R }s s JZ }Z Ist 8$ $ RBt$IBR t I$P t R $t %sjBR I P {Z t{$s * t B I Zts 8$R8s Ps8$j$s I $tR Z8 t BR jBR 8? sR } JZ K tBR } BIZ{ t R$ 8} RBt$IBR I P {Z t{$sR RZ} $B R ]B8}? s tR }B ` 8}jB Zt %$Bj? t {Bt Zt {Bt sAs`B B Zt Rs-BP? Bt RB} stB {Bt Zt Rs-BP? Bt As`B n
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
;d
3$ d *$? sjB B I RB IBR
VZtJZ jBR } BAj 8sR I sZI$A$j$IsI I pZjj$% }ZI$ R t R RZ} sIBR - tI$ tIB I sj Zts 8st s RZ {s}s{$IsI sZI$ $%s }s s I { s j YsAjs I jBR j$j$}Z $ tR R k A BAI$t ts Z$stBR B}s ? s8BR {Bt B B {Bt s $ 8}B ]ZstIB Zts } RBts } BtZt{$s Zts P sR {B s {B8B }B ` 8}jB " Z tBR I? sR" 8}j s { {s I d R ZtIB I $ 8}B t 8$ $ BIsR jsR %$A s{$Bt R RBtB sR JZ PB 8st jsR IBR }sjsA sR =t $ st I BAI$t ts Z $j$9s jsR 8$R8sR %$A s{$Bt R R? BjB JZ I P {Z t{$s 8? sR As`s }s s s ${Zjs js P sR 7$ Z$ tIB {Bt j R t{$jjB 8BI jB sIB} sIB 8}j s ? s }s s jjB Zt } $BIB d1 % { R 8skB }Z R B JZ P {Z t{$s k } $BIB RBt $t% Rs8 t } B}B {$Btsj R ej $ st tBR I %Bj% ? s j RsjZIB 8s $tsj t d;; R ZtIBR {sR$ IBR 8$tZ BR k 8 I$B $ t sR tBRB BR j 8BR t %B9 sj s R s j? t s I - B t ZtBR {$t{B R ZtIBR j $ st $t% $ ? s d1 8$tZ BR =t js}RB I $ 8}B RZh{$ t {B8B }s s s{sAs {Bt jsR AZ tsR $t t{$Bt R I {ZsjJZ$ s I {Bt $tZs js {Bt% Rs{$? Bt {Bt j $ st ej } BAj 8s R ? s s8A$? t tB sAj {ZstIB pZjj$% sR I$ $ $ R s Zt j$j$}Z $ tR {Bt j AZ tBR I? sR I $ B R} sR js R}Z R s JZ I${ st jsR tB 8sR I js AZ ts IZ{s{$? Bt 7$ Yst R{Z{YsIB sj Zts % 9 Zt I$R{B I nn }8 s ;x }8 }BI ? st t Zts {$ s $I s I jB JZ RZ{ I ? s d n z $t 8$j j ZsR I %$s` RZA8${ BR{? B}${B
V? Zt }BI 8BR $8s $ts $s8 t {js B R Z$ IZ{$ tIB j s8sK tB WBR sI t s8BR t Bt{ R t j PsR{$tst 8ZtIB I jsR } JZ K tsR I$8 tR$Bt R ej RZA8s $tB I js } j? {Zjs z$s` sjZ{$tst R IZ{$IB `Zt B {Bt RZ $}Zjs{$? Bt sj s8sK tB I Zts As{ $s st R I R $tk { sIB g t js {B $ t Rst Z? t s I j R$R 8s s $sj I Zt R YZ8stB Ns 8$t? ZR{Zjs $}Zjs{$? Bt $ t js 8$R$? Bt I I R Z$ Zt {B? s ZjB jB{sj$9sIB t j { A B I Zt $8}B st {$ t ? h{B et j js B tB% jsIB I js } j? {Zjs yRss{ VR$8B% R{ $A U "_B JZ j {B? s ZjB I j { A B tB }Z I R sj{st9sIB I RI PZ s Os j YsA? s I${YB R B _B {BtR$ Z$ t 8$t$s Z $9s 8BR Zt RZA8s $tB jB $tk { s 8BR t Zts s $s k {Bt j {s}$ ? st !b tR t jsR 8? sJZ$tsR k kB {B8B
© Los autores, 2001; © Edicions UPC, 2001.
;1
* $t Bt s e$tR $t
]ZsI B d n 5_B JZ? jsR YB 8$ sR tB Yst IB8$tsIB js q$ s2 et Zt I$% $IB s ? {ZjB j ts Z sj$R s 3 $ R G G t wd EMD sj$9s Zts {B8}s s{$? Bt t jBR R R YZ8stBR k jsR YB 8$ sR ej sZ B I${ JZ tBR R }s st I jsR YB 8$ sR 8Z{YsR {BRsR } B JZ j s8sK tB R Zts I$P t{$s 8Zk $8}B st }B jsR {BtR {Z t{$sR JZ s{s s NBR s Z8 t BR JZ R$ Z t $jZR st R ? Zt j sZ B }B JZ? jsR YB 8$ sR tB Yst jj sIB s 1*& JIT j 8ZtIBU 6 jsR YB 8$ sR tB }Z I t Ys{ ZRB I j PZ BU T j s8sK tB { ? ${B I Zts YB Z s R 8skB JZ j s8sK tB 8 I$B I Zts YB 8$ s wsj I IB I d {8D T tB }Z I t sK tsI$ {B8AZR $Aj }s s 8st t %$%s js YB Z s 6 jsR YB 8$ sR tB }Z I t Z $j$9s s 8sR t$ ZRs Y s8$ t sRU T jsR jst9sR k jsR 4 {YsR }$ I t P { $%$IsI {ZstIB R IZ{ t s Zt s8sK tB st } JZ K tB T Zt 8s $jjB } JZ K tB }BR Zts t ? s {$t? ${s $tRZh{$ t }s s Y$t{s Zt {js%$ B 6 jsR YB 8$ sR tB }Z I t j j$A BR I RZ sjjsU T jsR YB`sR R ? st I 8sR$sIB I j sIsR {B8B }s s }BI R }s s jsR w P { B I jsR PZ 9sR I {BY R$? BtD T }BR t }B{sR {? jZjsR { A sj R 6 jsR YB 8$ sR tB }Z I t PZ8s t$ YsAjs U T tB }BR t }Zj8Bt R }s s sARB A j YZ8B k tB }Z I t t{ tI PZ B T tB {$ {Zjst }B RZ $t $B {B $ t R I s$ JZ } B{ I t R I RZR }ZjT 8Bt R s{ $% t RZR {Z IsR %B{sj R
]Z R $? Bt I sjjs
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
;n
6
jsR YB 8$ sR tB }Z I t js%s R U T jsR B sR I s Zs I js IZ{Ys R ? st {B8B } Bk { $j R }s s RZR } JZ K tBR {Z }BR T RZ {Z }B R ? s $8} tsIB I
JZ$ $ts
RZAR st{$s JZ } j j s Zs
T tB }Z I t Rsj$ I j s Zs {ZstIB {s t t Zts AsK t s jj ts t$ }Z I t R {s R {Bt Zts BsjjsU JZ Is ? st sIY $IsR t RZR hA sR {B8B RZ{ I {Bt jsR B sR I s Zs {ZstIB tBR R {s8BR
_BI 8BR I {$ {B8B }Zt Zsj$9sAs t d 1M j hR$? BjB B A $ ? st${B FBYt JZ t 8BR j s8sK tB `ZR B sI {ZsIsR
7 <sjIst
eR I {$ JZ {sIs R %$%B $ t jsR I$8 tR$Bt R 8? sR
}$jB B %$s`s 8BR YsR s j {B? s ZjB Vjj? *Z%sj k RZ skZIst $RR _ RBt sj$9s ? st js B} T s{$? Bt" NsR $8}j${s{$Bt R 8$j$ s R I Zt } B{ I$8$ t B P { $%B I IZ{{$? Bt RBt P? s{$j8 t $8s $tsAj RU "et } $t{$}$B }BI 8BR IZ{$ Zt YB8A sj s8sK tB I Zts As{ $s I Zt q ? B ${s8 t js 8$t$s Z $9s{$? Bt tB $ t j? 8$ _BI ? s8BR IZ{$ Zt
%$ ZR I Zt s ? B8B
`? {$ B {Bt BIBR RZR YB8A R k RZ JZ$}B I 8BIB JZ {Z}$ st I t B I Zts {s`s I { $jjsR q ? B ${s8 t }Z R }BI ? s8BR t%$s R s {s`s I { $jjsR sj jZ s {Bt% t$ t k }Bt j `? {$ B t s{{$? Bt I R}Z? R I I %Bj% j s RZ s8sK tB ts Z sj $ t R B2" 5]B8} tI j sj{st{ JZ
] $s Z s wh{{$? BtD pBI9$jjs p$ st I BAI$t ts <B8A {BjBRsj Z` {BjBRsj $t Bt <B 8$ s $ st qs ? st Zjs $ st <B8A 8 t Zst N$j$}Z $ tR
qs8sK tB d1( 8
] $s Z s w sjD qk sttBRsZ ZR i iBA GsIjBb pB $js <B 8$ s {B8? Zt V sK ts s ? st Zjs _sZj$t ZR R
qs8sK tB 8
1d 8 dM 8 1, 8 d, M 8 (, 1 E
dx 8 dx 8 d( 8
M8 1( {8
1 {8
M {8
Ed {8
dx {8
qsAjs d d qs8sK tBR I I$P t R R R %$%BR I js h{{$? Bt {$ sIBR t j - B {BtP Bt sIBR {Bt jBR I RZR YB8? BjB BR sj R ej s8sK tB I R BR IZ{$IBR R R YZ8stBR R I j B I t I Zts I? {$8s I 8${ s eR I {$ JZ I$ 9 8$j YB8A {$jjBR I RZ sjjs I$R}Z R BR ZtB t{$8s I j B B 8 I$ ? st Zt 8$j? 8 B qst B jsR I$8 tR$Bt R I j RZA8s $tB {B8B jsR I jBR YZ8stBR R YsA ? st IZ{$IB t Zt Ps{ B I R{sjs d 8$jjBt R wd U d
d( D _s s jjBR BIB t j $t $B I j RZA8s $tB }s { tB 8sj
-
8$ t sR JZ PZ s I ? j BIB s}s { sZ8 t sIB t Rs 8$R8s {st $IsI * `stIB sj 8s t t sR t {Z t s JZ PZ BIsIs s 8$ sI I jBR jBR tB sAj R P { BR %$RZsj R I js } j? {Zjs w ?
© Los autores, 2001; © Edicions UPC, 2001.
;;
* $t Bt s e$tR $t
3$ d d( ej RZA8s $tB 8$t$s Z $9sIB k j JZ$}B I {$ t ? h{BR I js } j? {Zjs z$s` sjZ{$tst >3st sR ${ zBks d EEH %$% t Zts - sB I$ts $s BI$R s t j $t $B I j {Z }B YZ8stB sK tBR R R t s {ZstIB j {BtB{$8$ t B I j $t $B I j {Z }B YZ8stB s Zts R{sjs 8${ BR{? B}${s I$R sAs 8Z{YB I j s{ ZsjD k jsR s% t Z sR %$%$IsR }B jBR 8$t? ZR{ZjBR 8${ BtsZ sR {Bt j? BAZjBR Ajst{BR k As{ $sR {Bt% $IBR t $tRBR} {YsIBR t 8$ BR 8Z{YBR RBt jBR } BAj 8sR JZ Ys{ t $t%$sAj Zt %$s` I R sR {s s{ ? R ${sR _ BAj 8sR $ RBjZAj R $t{jZRB }s s Zt R{ $ B I js sjjs k {Z RBR I VR$8B% {B8B ? j 8$R8B Ys {BtB{$IB et j 8ZtIB I jsR } JZ K tsR I$8 tR$Bt R sIJZ$ t j %st{$s PZ 9sR JZ s} tsR $ t t $8}B T st{$s t tZ R B 8ZtIB 8s{ BR{? B}${B ej 8ZtIB I jBR B st$R8BR } JZ K tBR R ? s BA tsIB }B jsR PZ 9sR I s s{{$? Bt t 8Bj? {ZjsR I tB8$tsIsR PZ 9sR I {BY R$? Bt JZ $ t t Zt B $ t j? { ${B et Zt j? JZ$IB Zts 8Bj? {Zjs JZ R t{Z t s j `BR I js RZ} h{$ k I jsR }s I R I j {$}$ t JZ jB {Bt $ t t R s s? Is }B j R B I jsR 8Bj? {ZjsR JZ js BI st NsR 8Bj? {ZjsR R$ ZsIsR t js RZ} h{$ R? BjB RBt s s? IsR }B jsR % {$tsR k }B jsR JZ R tT {Z t st I As`B k $ t t tI t{$s s I R}js9s R Ys{$s j $t $B I j j? JZ$IB NsR 8Bj? {ZjsR RZ} h{$sj R -} $8 t st t {Bt`Zt B Zt s s{{$? Bt Ys{$s I t B I j j? JZ$IB I A$Is s jsR B sR eR B Ys{ JZ js RZ} h{$ j$A I jBR j? JZ$IBR R {B8}B {B8B R$ R s sR I Zts 8 8T A sts j? sR ${s Ns PZ 9s }B Zt$IsI I jBt $ ZI RZj st R I tB8$ts tR$? Bt RZ} h{$sj Ns tR$? Bt RZ} h{$sj $ tI s {Bt s js RZ} h{$ I jBR j? JZ$IBR k R js R}BtRsAj t B BR P { BR I JZ jsR B sR } JZ K tsR I Zt j? JZ$IB $ tIst s sIJZ$ $ PB 8s RP? ${s; NBR
ej s8sK tB 8? s-$8B JZ }Z I t jj s s t st R I {s jsR B sR I s Zs JZ R PB 8st t Zts B s I } tI I js js{$? Bt t j } RB JZ jsR 8}Z`s s {s k js tR$? Bt RZ} h{$sj JZ jsR 8st $ t sIY $IsR sj {YB et js q$ s j sI$B 8? s-$8B JZ }Z I t Zts B s st R I {s I j {YB R $tP $B s (, x {8 ;
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
;N
BA` BR } JZ K tBR tB $ t t Zt } RB RZh{$ t }s s B8} R s 8 8A sts k }Z I t I Rj$9s R RBA js RZ} h{$ j? JZ$Is wtB 4B st }B JZ R$ jBR RZ8 $? R 8BR tB }BI ? st Rsj$ D Ns PZ 9s JZ R 8st$h R s {B8B js tR$? Bt RZ} h{$sj t Zt $tR { B JZ } 8st { RBA Zt j? JZ$IB R$t YZtI$ R R } B}B {$Btsj sj } ? 8 B I RZR }s sR t js 9Bts I {Bt s{ B {Bt j j? JZ$IB 7 s s I Zts PZ 9s JZ I } tI I j s8sK tB ej I$? s8 B JZ I A ? s t Zts }js sPB 8s {$ {Zjs I } RB I R} {$sAj }s s JZ js tR$? Bt RZ} h{$sj I j s Zs PZ R {s}s9 I RBR t j } RB I Zt YB8A I A ? s R gI ZtBR n ,8 Vj tsIsIB JZ R 9s8AZjj t j s Zs tB j RZj s I$P? {$j % t{ js tR$? Bt RZ} h{$sj V RZ Ps%B `Z st j } RB I RZ {Z }B k js } JZ K ts RZ} h{$ JZ } R t s {ZstIB {Bt s{ s {Bt j j? JZ$IB =t s% 8s $ts {B8B j } j? {stB s} B% {Ys }s s } R{s js $t {$s {BtR Z$Is w} RB k % jB{$IsID t j %Z jB t }${sIB } t stIB t j s Zs k RZ8 $? tIBR s js } BPZtI$IsI t { Rs $s 5+Z? RZ{ I ? s {Bt Zt $tR { B {B8B Zts 8BR{s JZ $t t sR BA t RZ sj$8 t B jst9? stIBR sj s Zs {B8B jB Ys{ Zt } j? {stB2 N R ? s I j BIB $8}BR$Aj s s% Rs js j? sR ${s RZ} h{$ I j j? JZ$IB 5+Z? 8 I${ t }Z R I jBR RPB 9sIBR 8${ BtsZ sR I js } j? {Zjs2 5_BI ? st s s% Rs st P? s{$j8 t js RZ} h{$ I js Rst j? JZ$Is }s s }sRs sj s$ I j }Zj8? Bt2 eR ? s {js B JZ tB V RZ I$8$tZ s R{sjs js tR$? Bt RZ} h{$sj R ? s st stI JZ j R $8} I$ ? s s s% Rs js RZ} h{$ I R }s s{$? Bt t s8ABR 8 I$BR gk sI$? BR } j? {Zjs NsR t { R$IsI R I j Z$? Bt BAj$ st s8A$? t s }sRs }B sj B B BR P { BR ej RZA8s $tB 8$T { BR{? B}${B _ B ZR R I R}js9s }B j B t Rst Z? t B sj {B8B jB Ys ? s ZtB I s8sK tB tB 8sj }B j PBtIB B{ ? st${B eR B R ? s {$ B R$ jsR 8Bj? {ZjsR PZ R t $tht$ s8 t } JZ K tsR _ B jsR 8Bj? {ZjsR I js Rst RBt {B8}s sAj R sj s8sK tB I j RZA8s $tB 7Z I R}js9s8$ t B R % ? s s s? Zt 8? sR s{ t ZsIB t sP { sIB }B st B }B j jjs8sIB 8B%$8$ t B A Bbt$stB w j P { B R ? jBR $}Zjst R JZ Rsj t I j RZA8s $tB k tsIst t j 4Z$IB Rst Z? t BD ej 8B%$8$ t B A BbT t$stB R j 8B%$8$ t B ? s ${B sj s B $B JZ } R t s Zt BA` B } JZ K tB t j R tB I Zt 4Z$IB I A$IB sj AB8As I B {Bt $tZB I jsR 8Bj? {ZjsR I ? R 3Z I R{ZA$ B }B j AB ? st${B R{B{? R iBA Bbt t j sK tB dM1 $ t sR R ZI$sAs jBR stBR I }Bj t BAR %? B {? B8B ZtBR {Zst BR stBR t RZR} tR$? Bt t s Zs R 8B%? st k BR{$jsAst sj s9s ej P? R${B P st{? R F st s t d (M I R P t? B8 tB i sj$9stIB } {$RsR 8 I${$Bt R {Bt _ $t wdM (ud ;1D R B{Z}s ? }s ? {ZjsR RZR} tI$IsR t s Zs {B8} BA? B jsR {Zs{$Bt R k {B BAB ? B jsR -}j${s{$Bt R I j } BAT j 8s JZ YsA? s } B}Z R B VjA e$tR $t t d (x _B RZ sAs`B _ $t {$A$ ? s j } 8$B WBA j I P? R${s t d 1E 57 $8s $tst tsIstIB t R sR {BtI${$Bt R {$A$ tIB j $8}s{ B I {ZjsRD JZ jjZ % t I BIsR }s R2 } Bk { $j R I { {s I Zt { t ? 8 B I s8sK tB wjsR 8Bj? _ BAj 8? s ${B RZj s ? s s8A$? t j s%st{ I j 8${ BRZA8s $tB }B j 4Z$IB Rst Z? t B ej I R}js9s8$ t B I Zt BA` B B I Zt st$8sj t j R tB I Zt 4Z$IB ws Zs s$ D %$ t I 8$tsIB }B js js{$? Bt -$R t t jsR PZ 9sR I $t {$s wI } tI$ t R I js 8sRs k I js % jB{$IsI I j BA` BD k jsR PZ 9sR %$R{BRsR wPZ 9sR I P ${{$? Bt JZ s}s { t t jsR {s}sR Zst RBA j 8$R8B 7 Ys {B8} BAsIB JZ j %sjB I j {B{$ t t s8AsR I 4Z$IBD JZ s{ ? PZ 9sR I tB8$tsIB t? Z8 B I i ktBjIR w {$A R tB8A t YBtB I j $t t$ B A $ ? st${B !RAB t i ktBjIR wdM;1Td d1D }$Bt B t jBR R ZI$BR RBA j 8B%$8$ t B I jBR 4Z$IBRD I } tI I j s8sK tB I jBR st$8sj R NsR s% R jBR } { R stI R k jBR 8s8? P BR 8s $tBR }BR t t? Z8 BR I i ktBjIR stI R NBR B st$R8BR } JZ K tBR wAs{ $sR R} 8s B9B$I R D t
© Los autores, 2001; © Edicions UPC, 2001.
;-
* $t Bt s e$tR $t
{s8A$B $ t t t? Z8 BR I i ktBjIR As`BR eR B R$ t$h{s JZ t j 8ZtIB I jBR R R } JZ K tBR jsR PZ 9sR %$R{BRsR RBt 8? sR $8}B st R JZ jsR $t {$sj R =ts As{ $s tB }Z I 8B% R t j s Zs {B8B jB Ys{ Zts Asjj ts * $ Zsj PB 8s Zt 8BRJZ$ B tB }Z I }jst s {B8B Zt s ? Z$js =t YB8A JZ tsIsR t j s Zs t jsR {BtI${$Bt R t JZ jB Ys{ Zt R} 8s B9B$I tI ? s R $sR I$h{Zj sI R }s s I R}js9s R U gR ? s {B8B $t t s tsIs t Zts }$R{$ts jj ts I 8$ j B 8 js9s {Bt js $8}BR$A$j$IsI sK tsI$Is I tB }BI 8B% t$t Zts }s I j {Z }B s 8? sR I Zt { t ? 8 B }B 8$tZ B 7$ t RsR {BtI${$Bt R {BtR$ Z s%st9s ZtBR }B{BR 8 BR t Zt }s I R 8stsR }Z I {jsR$h{? s R j t jBR 8 `B R tsIsIB R I As`B t? Z8 B I i ktBjIRN _s s JZ j RZA8s $tB _ B ZR I z$s` sjZ{$tst 8BI jB s R{sjs d U d 8$jjBt R I Zt RZA8s $tB sj R I R}js{ RZ8 $IB }B j 8$R8B 8 I$B I js 8$R8s PB 8s t JZ jB Ys{ ? R I A ? s 8B% R s Zts % jB{$IsI d 8$jjBt R I % { R RZ} $B eR I {$ R$ j RZA8s $tB I s8sK tB B}${B I A ? s I R}js9s R s tB 8sj R 8Z % s Zts % jB{$IsI I d1 ,8>Y j RZA8s $tB 8${ BR{? js $t{ ? Aj % jB{$IsI I g1(( 8$jjBt R I ,8>Y e-$R t B BR } BAj 8sR 8 tB R Y? sA$j8 t RZ j BR t js tB% js _B ` 8}jB 5{? B8B R}$T s ZtsR 8Bj? {ZjsR I s$ - $B tB {Bt s? IsR JZ }BR t Zt s8sK tB I sj ZtBR 8$j? 8 BR }s s jBR $t ? }$IBR } B s Bt$R sR2 5{? B8B sR$8$jst R sR tB 8 R 8Bj? {ZjsR RZR IZ{$IBR }ZjT 8Bt R2 sR s I$R}Bt I Zt 8 {st$R8B {B8B j I j RZA8s $tB 8${ BR{? B}${B JZ } 8$ IZ{$ {ZstIB Ys{ Psj s j s$ YsR s j s8sK tB t { Rs $B }s s JZ R s R}$ sAj V s% Rs {Bt Ps{$j$IsI {B8B Ys{ ZtB I jBR } B s Bt$R sR jsR htsR 8 8A stsR I jBR ZABR {s}$js R }s s s{{ I sj }Zj8? Bt -$ Zt RPZ 9B 8Z{YB 8skB JZ j JZ R tBR 8Z R s t j hj8 e- sB I$ts $s8 t I j sIsR R sR 8 8A stsR }BR t }s s j t{B $IB 8${ BtsZ s Zt R} T RB JZ$%sj t I ZtBR ;( 8 et js tB% js s VR$8B% R s {$P s j }s {? s I 8sR$sIB j %sIs sR? JZ I j$A sIs8 t js IZ`B s ZtBR 8? sR Bj sAj R {Zst BR 8 BR et B s R{ ts I js } j? {Zjs $RR _ RBt R s s{sIs }B st ${Z }BR 7 s s I 8Bj? {ZjsR I } B ? tsR JZ VR$8B% $8s $t? B {B8B } JZ K tBR {B}BR A $jjst R I ZtBR {$t{B { t ? 8 BR I st{YZ s s js R{sjs I jBR 8${ BtsZ sR qs8sK tB ? R R? 8? sR s{B I {Bt jB R} sIB ej htsj I js Y$R B $s t js } j? {Zjs w} 8? stBR I R% js j R { BD RZj s }s sI? B`${B ej RZA8s $tB k j s$IB I js -} I${$? Bt RBt t Zjj$IBR }B Zt j Z{B{$ B w j? BAZjB Ajst{B I js Bt {BtR$ Z Rsj$ I j {Z }B YZ8stB t JZ Yst %$%$IB Rst D 8$ t sR j R B I js $}Zjs{$? js 8? sR $t{ ? Aj I jsR s% t Z sR t j 8B8 t B `ZR B t JZ 8}$ 9st s {Z} s RZ sjjs tB 8sj et AZ ts j? B ${s R 8$R8B } B{ RB I A ? st R Z$ jB s8A$? t }B 8Zk I$R} RBR JZ R BR R t{Z t t jBR $tPB ZtsIBR R BR I j 8sj%sIB }$jB B ${Ys jR k I j RZA8s $tB JZ } 8st { t t j $t $B I j {Z }B y 8$R$Aj 8 t j }s{$ t RZj s ? s 8Z B k I tsIs YsA ? st R %$IB jBR RPZ 9BR }B I RYs{ j j {B? s ZjB { A sj WsI$ R I$B {Z t s I jjB VPB ZtsIs8 t VR$8B% {s8A$? B t js tB% js R htsj $t t$? stIBR jsR }s s Rs{s I j }s{$ t j j Z{B{$ B {Bt j 8sjB k j RZA8s $tB t Zjj$IBR V Z8 t BR R$8$js R s}s { t t js tB% js z$s` sjZ{$tst yyU I R $tB j { A B >3st sR ${ zBks yyU * R $ts $Bt s$t d M H {Bt $tZs{$? Bt I js {B8 t sIs s8A$? t R{ $ s }B yRss{ VR$8B% k t js %$R$? Bt 8BI ts I js } j? {Zjs st $B ej {Y$} } BI$ $BRB
zsjB R s} B-$8sIBR I j t? Z8 B I i ktBjIR {B R}BtI$ t s I$P t R B st$R8BR JZ tsIst t s ZsU Asjj ts d(M tsIsIB YZ8stB d(; R} 8s B9B$I d( ; As{ $s d( E N
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
;
qs8sK tB RZA8s $tB
_ B ZR
d( d,
$RR _ RBt s $s sB s wI$? s8 BD s Z`s Y$}BI? 8${s wI$? s8 BD j? BAZjBR B`BR As{ $s BRB 8 8A sts R }s s{$? Bt %$ ZR st ${Z }B 8Bj? {Zjs I s$
w 8D
eJZ$%sj t{$s ? Zt j I d(( ,8 I I$? s8 B ? Zt j I d( ,8 I I$? s8 B AZJZ sZ BA? ZR Z Rs }s I I ;( 8 } jB s I AsjBt8stB {st${s }Zj s
d( 1 d( n
d( d(
d(
d( M d( d( d(
d( x d( E d( E
qsAjs d 1 ]B8}s s{$? Bt I {? B8B % t jsR {BRsR jBR 8${ BtsZ sR I z$s` sjZ{$tst >3st sR ${ zBks d EEH V -{ }{$? Bt I j RZA8s $tB k I RZ $t $B BIsR jsR I$8 tR$Bt R I j R B I j Zt$% RB j R }s { ? st 8Zj $}j${sIsR }B Zt Ps{ B I R{sjs I d 8$jjBt R _s s t Zts $I s I j s8sK tB js $%B I jBR BA` BR JZ tBR BI st }BI 8BR t jsR R$ Z$ t R js{$Bt R s} B-$8sIsRU Zt %$ ZR R s Zt YB8A {B8B ? R s js q$ s Zt ? s B8B R s Zt YB8A {B8B ? R s js ? B A$ s I js q$ s sj I IB I j 7Bj Zt j { ? Bt R s Zt YB8A {B8B ? R s js I$R st{$s I js q$ s s js R jjs 8? sR } ? B-$8s
=t$% RBR RZA8${ BR{? B}${BRU 8ZtIBR I t B I B BR 8ZtIBR _BI 8BR R Z$ RZ8 $? tIBtBR t j 8${ B8ZtIB sj{st9stIB sYB s jsR R{sjsR RZAs ? B8${sR Ns $I s R 8Bt s s js ? }B{s I jBR sAs`BR }$Bt BR I P? R${BR {B8B e iZ Y PB I k W BY t B BR RBA js ts Z sj 9s I j s ? B8B et jBR sK tBR % $t I R R$ jB sj ZtBR gYsA$ sIBR I R{ $ B R {BtR$I s Bt sj s ? B8B {B8B Zt R$R 8s RBjs t 8$t$s Z s AsR? stIBR t jBR 8BI jBR {$ t ? h{BR t AB s I js ? }B{s {Bt jBR j { Bt R t j }s} j I }jst sR js 8$R8s 8st s JZ j 7$R 8s 7Bjs tB R ? s 8? sR JZ Zt R$8}j s ? B8B I j Zt$% RB isk ]Z88$t R Zt } Bj? h{B R{ $ B {Bt {$ BR {BtB{$8$ t BR {$ t ? h{BR wtB t %stB PZ R { s $B I j 8$R8B qYB8sR V eI$RBt IZ st {$t{B sK tBRD I Rs Bjj? B R sR $I sR t
I B B >qY p$ j $t Y pBjI t V B8 d d H k _ $t{ RR BP Y V B8 >d 1 H =ts I B s JZ R $ s k t{B s jBR } RBts` R s %BjZt sI Ps{$j$ s js {Bt -$? Bt t jBR IBR 8ZtIBR Fs8 R j$RY t q tR$? Bt RZ} h{$sj >7Z Ps{ q tR$Bt d x1H } R t s Zts 8Z` 8${ BR{? B}${s { sIs t? ${s8 t Z{YB st R t dMxM 3$ 9 F !: $ t YsA? s s%st9sIB js $I s I js -$R t{$s I Zts }BR$Aj s9s I YB8A R 8${ BR{? B}${BR et
Ns {Y${s I j s ? B8B
Ns j t I I$s8st >qY *$s8BtI N tR dMxMH
I R{ $A jsR %${$R$ ZI R I Zt 8${ BA$? BjB B jB{s8 t ts8B sIB I Zts 8Z` st I$8$tZ s JZ st R? BjB R %$R$Aj s s%? R I j 8${ BR{B}$B k JZ YsA$ s t Zts B s I s Zs Vj 8s t I jBR } BAj 8sR }jst sIBR }B jBR {s8A$BR I R{sjs JZ Y 8BR % t$IB {B8 t stIB % s8BR s {Bt $tZs{$? Bt s JZ? B BR } BAj 8sR I A ? st Ys{ P t jBR Y? B R RZA j { ? Bt${BR I ]Z88$t R et R $}B I js BR R $ tB s j Y {YB I JZ Zts IZ{{$? Bt I s8sK tB {B8}B s s8A$? t Zt {s8A$B t js IZ s{$? Bt I js %$Is k I RZ $ 8B NBR st$8sj R } JZ K tBR sR I } $Rs j %$% t 8 tBR JZ j YB8A k $ t t Zts -$R t{$s 8Zk s{ $%s w R}$ st 8Z{YB 8?
© Los autores, 2001; © Edicions UPC, 2001.
;M
* $t Bt s e$tR $t
{B s9? Bt j R js 8? sR ? s}$IB 8Z % t jsR sjsR B jBR 8$ 8A BR s 8? sR % jB{$IsID _B ` 8}jB j $ 8B {s I$s{B I j s ? Bt R I E(( js $IBR }B 8$tZ B j I j s B d1( j I j YB8A 1 j I j j Pst t n( k ;( j I js Asjj ts t dx k 1( 7$ R sAj { 8BR {B8B IZ s{$? Bt I Zts %$Is j JZ$%sj t s d ((( 8$jjBt R I js $IBR I j {B s9? Bt BAR %s 8BR JZ Zt s ? Bt %$% ZtBR n sK tBR Zt s B dx k Zt j Pst 8? sR I E( sK tBR 7$ Z $j$9s8BR I${Ys js{$? Bt -} $8 t sj }s s jBR R R YZ8stBR I A ? s8BR %$%$ st R? BjB ZtBR gn( sK tBR _B PB Zts tBR Rsj$8BR I js tB 8s V}s t 8 t }Z R jBR st$8sj R } JZ K tBR %$% t R ? Zt Zts R{sjs I $ 8}B 8? sR {B s JZ jBR st$8sj R stI R 7$ - s}Bjs8BR R s tI t{$s sj 8ZtIB RZA8${ BR{? B}${B k Bt {js BD tBR Is 8BR {Z t s {BtR$I s8BR JZ jBR j { Bt R RBt sj8 t 8ZtIBR w}Z s h{{$? JZ js %$Is RZA j { ? Bt${s I A ? s R - sB I$ts $s8 t {B s * ht$8BR j sK tB j { ? Bt${B {B8B j $ 8}B JZ s Is Zt j { ? Bt t sj$9s Zts %Z j s {B8}j s sj t? Z{j B s ? B8${B et j 8BI jB I iZ Y PB IT BY }s s j s ? B8B I Y$I ? B tB j j { ? Bt JZ B A$ s sj I IB I Zt t? Z{j B JZ {Bt $ t Zt } B ? Bt P { ? Zs ZtsR d(dE %BjZ{$Bt R {sIs R ZtIB 7$ R sAj { 8BR {B8B }s ? Bt I {B8}s s{$? Bt js IZ s{$? Bt I j sK tB R jj s8BR s js {Bt{jZR$? Bt I JZ js sR I } $Rs JZ t tZ R B 8ZtIB 8s{ BR{? B}${B %$Is RZA j { ? Bt${s stR{Z ZtsR d(1n % { R 8? et R R t $IB j $ 8}B }Z I {BtR $ Z$ R t Zts As s s? Zt 8? sR I$P? {$j I RZ} s JZ j 8$R8B R}s{$B _s { {js B }Z R JZ s t$t ? Zt Y? B I {$ t{$s h{{$? Bt j R %$ ? s I 8Z{YB P { Zs 8? sR I IBR %$R$ sR R Z$IsR sj 8$R8B 8ZtIB RZA8${ BR{? B}${BU R$ t js R ZtIs %$R$ s R} sAs t{Bt s s jBR s8$ BR B s js s8sIs JZ I `? B sR j } $8 {Bt s{ B RZ I { }{$? Bt R ? s 8sk? ZR{Zjs st R? BjB t{Bt s ? s s RZR j `stBR j `st? R$8BR I R{ tI$ t R O RB sZtJZ YZA$ R %Z j B sR Zt A % js}RB I $ 8}B I R}Z? R I RZ } $8 s %$R$ s =tBR 8$tZ BR }s s j %$s` B } R t st 8$j R I 8$jjBt R I sK tBR j { ? Bt${BR e-$R s? Zt Zt } BAj 8s sI${$Btsj JZ {BtI${$Bts R BR Y$}B ? ${BR %$s` R V }s I t{Bt s Zt 8 {st$R8B }s s ts% s }B j %s{? B R}s{$B $t tZ{j s wsj 8 tBR jBR } B s Bt$R sR I z$s` sjZ{$tst I$R}Bt? st I j RZA8s $tB _ B ZR k I Zt 8 I$B {B8B js Rst }s s I RT s jB{sj$9s j 8ZtIB j { ? Bt${B {Bt% t$ t t jBR d(1n ? s B8BR wt? Z8 B I }js9s R D Psj s ? V%B sIBD JZ -$R t }B {sIs 8Bj I RZAR st{$s w t j {sRB I j Y$I ? B tB d 8Bj JZ$%sj Z8 B I R jjsR t tZ R s sjs-$s R I ZtBR {$ t 8$j s d s8B I R j 8 t BD ej t? 8$jjBt R k j I sjs-$sR JZ }Z Ajst j Zt$% RB {BtB{$IB R R $8s s8A$? t t {$ t 8$j 8$jjBt R e-$R t }B st B d(11 R jjsR t tZ R B Zt$% RB t? Z8 B s? Zt $tP $B sj I s B8BR -$R t R t Zt 8Bj I RZAR st{$s 5]? ? B8B B $ t s R t Zt Zt$% RB st tB 8 2 NBR s8st R I jsR 8B{$Bt R PZ R k I jsR s8sR I j$ st R }Z I t t{Bt s $tR}$ s{$? Bt t jBR js BR 7ZA8${ BR{? B}${B >7ZA8${ BR{B}${ d ndH k RZ R {Z js VbjB I =j8 >VbjB BP =j8 d ndH R{ $ BR }B j {s}$ ? st 7 _ , t jBR JZ R ts s js BI$R s I ]BZ t k eIbs IR Zt {$ t ? h{B s8 ${stB t %$s` I -}jB s{$? Bt }B j 8ZtIB RZA8${ BR{? B}${B I =j8 ej {Z $BRB I$R}BR$ $%B I %$A s{$? Bt j { ? Bt${s I R{ $ B t js tB% js JZ } 8$ IZ{$ j s8sK tB I BA` BR k R R %$%BR R AsRs R ? Zt j sZ B t JZ j 8B%$8$ t B I jBR j { Bt R sj I IB I j t? Z{j B s ? B8${B tB R {$ {Zjs R$tB Ts ? s tR T gs 8? Bt${B R$8}j ]Bt R? BjB TgR? BjB T s8B $ Zs sj %$A s{$? Bt R {BtR$ Z t{B j s8sK tB I js 8s $s _Z R BR s I$%s s j } B s Bt$R s I {$I s8A$? t -} $8 t s {Bt js s8}j$h{s{$? Bt I js %$A s{$? BtU {B8B RZj sIB sIJZ$ Zts Zt jsR j k R I R{sjs } B sjjs j IBAj I js YsA$ Zsj k Zt } RB I gx;( , w{B { B R ? 5I I? BtI Rsj$? B js 8sRs - s2D q sR B8s RZ } Bk { B B $ $tsj $t%$ js R{sjs k t{B
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
;
3$ d dd =ts YsA$ st I j 8ZtIB RZA8${ BR{? B}${B s js R} s I Zt I R sIB {Bt s{ B {Bt YsA$ st R I tZ R B 8ZtIB t{B t{B YsR s I t {B8}j s8 t j 8B%$8$ t B } $? BI${B I jBR j { Bt R wR$t JZ ? R BR {js B R ? s R } {$}$ t {Bt s j t? Z{j B s ? B8${BD I R{ZA $ tIB sR? j 8${ B $tB I =j8 j Zt$% RB I 8 tB s8sK tB }BR$Aj VY? R tsIs WB {Bt t B {Bt jsR $t{ ? Aj R stIst9sR }B R 8${ B8ZtIB j {$ t ? h{B $t%$ j } B{ RB I t{B $8$ t B k Rs s RZ 8ZtIB tB 8sj }s s %Bj% I tZ %B s =j8 k t{Bt s s VbjB RZ s8sIs 5_Zt ? s B {Z R $? Bt I RZ 2 O 5JZ? }sR? B {Bt j $ 8}B {s}$ ? st ,2 VZtJZ Zts % 9 R Ys s{ } sIB j sA st 8 {st$R8B I t{B $8$ t B jB I 8? sR }s { P? s{$j gqBIB j 8ZtIB sj 8$t$s Z $9sIB
]B8B Y 8BR %$R B js $t R $? Bt I Zt P $j$9st 8s s%$jjBRB B js -}BR${$? Bt s js sI$s{$? Bt }s { t R RZh{$ t R }s s {Bt% $ s Zt R tB 8sj t Zt $ st * `stIB sj 8s t js tB 8 tBR - sB I$ts $s I B s t{B IB s }s s IZ{$ I s8sK tB RZj s $8} R{$tI$Aj I$R}Bt I sj ? Zt I$R}BR$ $%B 8$t$s Z $9sIB $ t sR JZ jBR $ st R I G jjR B jsR YB 8$ sR s $ stT sIsR I Ns YZ8st$IsI t } j$ B BA $ t t j RZ}j 8 t B I 8sRs t { Rs $B {Bt js $t R $? Bt R sR Z ?j $8sR sj ? Zt YZ8stB I R} % t$IBD t jsR IZ{T I {B8$Is w$t{jZ$IB t j {sRB I ? {$Bt R I s8sK tB RZj s j? {$ B } Zt s R s I? BtI PZ s }s s js 8sRs RBA st VR? }Z R 5I s{Z IB {Bt JZ? 8 {st$R8B I A ? s PZt{$Bts Zt Y$}B ? ${B 8$t$s Z $9sIB 2 i {B I 8BR JZ R$ IZ{$8BR s Zts } RBts }B ` 8}jB YsR s js 8$ sI I RZ sj Z s t Bt{ R RZ %BjZ8 t R ? s B{YB % { R $tP $B sj %BjZ8 t $t${$sj ]st $IsI t js JZ R YsA ? s IZ{$IB s8A$? t RZ 8sRs et } $t{$}$B R 8? BIBR } 8$ t IB s I Zts {$ s AsR P? R${s jsR Y$}B ? ${sR I$R8$tZ{$Bt R I s8sK tBU T s} jB Bts8$ t B 8skB I jBR s ? B8BR I j {Z }B
© Los autores, 2001; © Edicions UPC, 2001.
N
* $t Bt s e$tR $t T I Rs}s ${$? Bt I Zts }s I jBR s ? B8BR I {sIs }B {$? Bt I j {Z }B T {Bt s{{$? Bt I jBR } B}$BR s ? B8BR
NsR IBR } $8 sR }BR$A$j$IsI R }Z I t R ? s}$Is8 t I R{s sIsR et j } $8 } B{ RB jsR sj sR } R$Bt R $t%BjZ{ sIsR s{sAs ? st {Bt js %$Is I j $tPsZR B YB8A {$jjB st R I sj{st9s j s8sK tB I R sIB O R B R$t t t {Z t s j P { B I Zts IZ{{$? Bt I js RZ} h{$ et {Zst B s js I jBR }$ R RBA js {Zsj I R{stRs 8$ t sR R {BtR %s j } RB I j {Z }B
R ZtIs }BR$A$j$IsI }Z I t s}Zt s R s Z8 t BR I $}B A$Bj? B ${BU Zt YB8A I j s8sK tB I Zt s ? Bt tI ? s Zt { A B I s ? Bt 57 Z$ ? s {BtR %stIB BIs RZ $t j$ t{$s2 Ns { s }BR$A$j$IsI R js JZ R Z $j$9s t js } j? {Zjs k sj RZA8s $tB
z$s` sjZ{$tst }s s IZ{$ s jBR } B s Bt$R sR
_ B {ZstIB jBR s ? B8BR R t{B t 5JZ? RZ{ I {Bt RZ 8sRs2
WB Y 8BR
{BtR Z$IB B s {BRs JZ sRjsIs j } BAj 8s s js R{sjs s ? B8${s yRss{ VR$8B% Z$Bt$R s k sZ B I j j$A B AsRsIB t js } j? {Zjs }jst s tZ %s8 t IBR }BR$A$j$IsI RU ? B8BR R 8st $ t t $t%s $sAj R sD jsR 8sRsR I jBR s AD jsR 8sRsR R IZ{ t } B}B {$Btsj8 t sj %BjZ8 t
et jsR {BtI${$Bt R I j s}s sIB sD js I tR$IsI I Zt j$j$}Z $ tR }B ` 8}jB I dx {8 I sj Z s R ? s d1
n % { R RZ} $B s js I Zt R YZ8stB JZ }BR Zts I tR$IsI j$ s8 t
RZ} $B s js I j s Zs ej %sjB RZj st R ? s 8Zk sj `sIB I jsR I tR$IsI R ? }${sR I jBR 8s $sj R {BtB{$IBR w$tP $B R s ZtsR $t s % { R js I tR$IsI I j s ZsD O tB I$ s8BR ks R$ tBR s{ {s8BR s s8sK tBR 8${ BR{? B}${BRU js 8sRs R {Bt{ t s ? s t Zt %BjZ8 t st } JZ K tB JZ tI ? s8BR Zts 8s $s I$P t I js B I$ts $s wR$8$js s js JZ }Z I t{Bt s R t R sI$BR s%st9sIBR I js %BjZ{$? Bt I sj ZtBR $}BR I R jjsRD s $s st - sB I$ts $s8 t I tRs JZ j
8${ BYZ8stB R YZtI$ ? s s s% RstIB js {B 9s R } PB stIB st R j } {YB I j WB }s { }Z R Zts AZ ts 8st s I Ys{ R } JZ K tB Ns Z ? j $8s
$t{BtR{$ t pZjj$%
{BtI${$? Bt s8A$? t } R t s $t{Bt% t$ t R =ts IZ{{$? Bt I 8sRs R$ t$h{s JZ ? R s R }$ I 5V I? BtI %s s }s s }Z R2 7? BjB {BtB{ 8BR Zts 8st s I JZ js 8sRs I Rs}s 9{s k R JZ R stRPB 8 t t ? s eR s {Bt% R$? Bt I 8sRs t t ? s R - sB I$ts $s8 t h{$ t k {BtR $ Zk js AsR I jsR AB8AsR s ? B8${sR et R B R t jB JZ } BAsAj 8 t R {Bt% $ ? s tZ R B YB8A {$jjB IZ{$IB
qBIBR R BR } BAj 8sR RBt $ tB sIBR t js } j? {Zjs {$ sIs et js % R$? Bt tB% jsIs R s{ } s R s Z ? j $8s }BR$A$j$IsI {Bt j sK tsI$IB I RZ}Bt JZ t j } B{ RB I {Bt s{{$? Bt js 8sRs %s s }s s 8B8 t ? st s8 t s Zts R} {$ I
Y$} R}s{$B I IBtI %Z j% {ZstIB R B ts sj g Zk 8sj VJZ? $ t t ZR I R js AsR }s s >qBB sI d M H Zts % 9 8? sR
s8sK tB tB 8sj 7 ? Zt VR$8B% % tI ? s s R }B{B 8? sR B 8 tBR sZtJZ t Zt t$% j I$P t {B8B IZ{$ Zts PB B sP? s 8st$}ZjstIB j t R B ?} ${sR {BtR Z$ R Zt 8$t$s Z $9sIB {sR B et j js B I j %sjB I Zts {BtR st Zt$% Rsj wjs
yRss{ VR$8B% } B}Bt Zt 8 {st$R8B sj ts $%B }s s I$R8$tZ$ I s8sK tB Ns 8BI$h{s{$? Bt
{BtR st I _jst{, JZ s}s { $t%BjZ{ sIs t BIBR
Bt I Zt jBR } B{ RBR ts Z sj R s R{sjs 8${ BR{? B}${sD } 8$ t R {sRB js 8$t$s Z $9s{$? BAB JZ R $t BIZ{$IB t j $t $B I j {Z }B I Zt {$ t ? h{B }s s }BI $t % t$ jB JZ$ ? Z ${s8 t Ns sj s{$? Bt I j %sjB I jsR {BtR st P? R${sR } 8$ jZI$ I Zts PB 8s j st k RZ $j jsR I$h{Zj sI R }jst sIsR }B jBR 8? BIBR I R{ $ BR 8? sR s $As VZtJZ
ts Z sj8 t VR$8B% tB tBR I R% js j } B{ I$8$ t B w{ZkB R { B }s { YsA R jj %sIB
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
N@
{BtR$ B sR RZ {$ t Psjj {$8$ t BD ej 8$t$s Z $9sIB 8}j sIB t js } j? {Zjs ej {Y$} } BI$ $BRB Zts % R$? Bt t }jst {B8 I$s I z$s` sjZ{$tst PZt{$Bts s AsR I Ys{ $ s 8Zk ? s}$Is8 t j BA` B JZ R JZ$ IZ{$ Zt RZA8s $tB 8BtB}js9s {BtR$ Z$ tIB JZ BIsR RZR }s R $t{jZ$IB j } B s Bt$R s JZ jB }$jB s R IZ9{st j s8sK tB RZh{$ t {B8B }s s %$s`s R$t } BAj 8sR }B j $t $B I Zt {Z }B YZ8stB Ns ? s}$Is B s{$? Bt }s { } B%B{s j P { B I 8$t$s Z $9s{$? Bt I R sIB sj Ps{$j$ s j {Bjs}RB I j BA` B yI s ? Bt s ]B8B {ZsjJZ$ s JZ R RZAs s Zts s s{{$? Bt $ s B $s I P $s B I }s JZ I s s{{$Bt R }Z I {B8} BAs js tI t{$s }B 8Zk ? s}$IB JZ R s j $ B tB R } {$Rs8 t s {s Ys{$s j ` I $ B R$tB s R $8}ZjRsIB }B P { B { t ? PZ B t R t $IB {Bt s $B {Bt s j sR$ t B V? Zt t j {sRB I JZ j 8s $sj I j RZA8s $tB PZ R {s}s9 I R$R $ jsR 8 tIsR PZ 9sR $t%BjZ{ sIsR t js B s{$? Bt JZ Is s t tI js } j? {Zjs tsIs {BtR Z$ ? s8BR {Bt R } B{ I$8$ t B I IZ{{$? Bt BIB jB 8? sR js {Z} s{$? Bt I j }$jB B t Zt R sIB 8? sR JZ stR t j {s}? ZjB 1 jBR } BAj 8sR I $%sIBR I js -}BR${$? Bt I Zt R YZ8stB js8 t sAj w%? s Zts j %sIs s{ j s{$? BtD
d ;
? sJZ$tsR k s $jZ $BR I ? R k B BR 8ZtIBR
isR{s{$ jBR }$ ? s8$I R k 8Bt sK tsR "T Z tBR I? sR TI${ Zts {? sj$Is %B9T Ns 8} s Z s - $B }B R$ j $t Rs s sj Z$ t R I 1M 0 ] Ns }BAjs{$? Bt I YBk I js BtZ A ddE R I MMd ddx {Bt Ld(1 {Bt R} { B s sk k Ld; dM {Bt R} { B sj } $t{$}$B I sK tB" ]B j sK tB 1nMd ? sR I M(( ((( } RBtsR R {Bt{ t st t ZtBR R$t Zjs R I$h{$BR jsR 8BtZ A eR sR I$h{s{$Bt R R ? st Y {YsR I YB 8$ ? Bt RZ} tRsIB k R ? st {BtR Z$IsR sj I IB I Zt ` { t sj I R %${$BR I 1(( 8 {Bt ZtBR {$8$ t BR JZ R - $ tI t YsR s jBR ;(( 8 I } BPZtI$IsI et {sIs }jst s %$% t d1( Ps8$j$sR t s}s s8 t BR I Zts RBjs }$ 9s {BtR $ Zk tIB t? Z{j BR sZ BRZh{$ t R I x B E }jst sR PB 8stIB {$ZIsI R I ;( }jst sR ]sIs 8BtZ A R ? s PB 8sIs }B d ((( }jst sR wR$ RZ}Bt 8BR ZtBR n 8 }B }jst s BA tI 8BR Zts sj Z s I n ,8 }s s R s I$h{s{$? BtD 7Bt 8ZtIBR { sIBR R$t s} tsR {Bt s{ B {Bt j - $B {Zks } $t{$}sj PZ t I t ? s R js {B8AZR $? Bt I jBR I R {YBR R? Bj$IBR } BIZ{$IBR k IBtI j -{ I t {sjB ? h{B t sIB }B js $t t 8sRs YZ8sts JZ YsA$ s j I$h{$B R Z $j$9sIB y8} R$Btst 53${{$? Bt2 7? eR s I R{ $}{$? Bt } B{ I I js tB% js ej 8ZtIB $t $B >qY GB jI ytR$I d dH I iBA 7$j% A 5_ B tB RBt jBR sR{s{$ jBR I <Bt,T Bt IBtI R Ys{$ts js }BAjs{$? Bt t IZ{$IBR {ZA? {ZjBR Zts ? }j${s s Zts R{sjs 8Z{YB 8? sR 8BI R s I R sR I$h{s{$Bt R2 Ns RBjZ{$? Bt JZ }jst s js tB% js }s s j PZ Z B I Zts q$ s RZ} }BAjsIs R js {BtR Z{{$? Bt t }s s j 8st t$8$ t B I Zts {jsR I$ $ t }Z R B JZ ? R s YsA$ s t jBR % ${sj w s8A$? }$RBR RZ} $B R B $t{jZRB 8? sR s $As s? Zt {B8B t j js B ? sR sjj? s I jsR tZA R I *B8$t B R ${sR2 ]ZstIB s8}j$s8BR s R{sjs 7st BRD 5eR }BR$Aj {BtR Z$ I$h{$BR I sj R {s s{ ? Zt R$R 8s {ZsjJZ$ s js {s s JZ RB}B s RZ AsR sZ8 t s {Bt j } RB k }B st B {Bt j {ZAB I Zts jBt $ ZI {s s{ ? R ${s et {s8A$B js R$R t{$s I js R Z{ Z s sZ8 t s {Bt js RZ} h{$ R I {$ {Bt j {ZsI sIB I Zts jBt $ ZI eR B RZj s {$ B }s s BIB R$R 8s P? R${B k tB R? BjB {B8B Y 8BR %$R B }s s jBR st$8sj R NBR I$h{$BR }Z I t R 8Zk sj BR }B JZ
© Los autores, 2001; © Edicions UPC, 2001.
N
* $t Bt s e$tR $t
jBR 8s $sj R {Bt JZ R {BtR Zk t RBt 8? sR R$R t R JZ tZ R BR YZ RBR RZR PB 8sR RBt I$P t R k sI 8? sR tB R 8Z % t et {B8}s s{$? Bt js AsR I Zt sR{s{$ jBR R 8? sR stI JZ js I jsR PB 8sR % sj R ts Z sj R I R Z{ Z s R$8$js {B8B Zts {sK ts B Zt `Zt{B _B ` 8}jB R$ Zt I$h{$B {B8B j e8}$ 7 s {Bt RZR nMd 8 I sj Z s PZ R Zt 8BI jB s8}j$sIB I Zts R Z{ Z s % sj ZAZjs {B8B Zt sjjB I $ B js st{YZ s I RZ AsR R ? s g$tP $B s jBR 1 8
-
ej YB8A sj $ Zsj JZ js ts Z sj 9s Z $j$9s t RZR {BtR Z{{$Bt R IBR R s $sR }s s {BtT s R s jBR JZ $8$ t BR I jsR j k R I R{sjs t Zt sZ8 t B I s8sK tBU sD e8}j s 8s $sj R 8? sR R$R t R VZtJZ R B s8A$? t } R t s sj ZtsR j$8$ s{$Bt R WB -$R t I$h{$BR I 8? sR I 1( 8 {BtR Z$IBR ? t s8 t I 8sI s jBR {BtR Z$IBR t }$ I s t {Bt sIBR {sRBR RZ} st jBR d(( 8 8$ t sR JZ jBR sj$9sIBR {Bt s{ B 8s {st jBR j ? 8$ R I j s8sK tB I jsR {BtR Z{{$Bt R s{ Zsj R wqB 7 s R I ]Y${s B ;;n 8 qB R 8 jsR I _ BtsR I Zsjs NZ8}Z ;xd, 8D AD *$R K ts R Z{ Z sR YZ {sR }s s IZ{$ j } RB B js {s s JZ I A t RB}B s NsR
{? Z}ZjsR js PB 8s I jsR %$ sR jBR s RBtsIBR { $8$ st jsR ? {t${sR JZ js ts Z sj 9s Ys I Rs BjjsIB }s s IZ{$ js {s s 8st t$ tIB js R$R t{$s I js R Z{ Z s wI RI jsR %? A sR I Zt } 9 YsR s jBR sjjBR I Y$ As B js PB 8s $t $B I Zt }$8$ t BD
NBR s RstBR k sAs`sIB R 8stZsj R I RI Ys{ $ 8}B RsA t JZ }s s {BtR Z$ sj B 8skB tB AsR s {BtR Z$ {sIs }s {Bt Zt s8sK tB } B}B {$Btsj8 t 8skB WB }Z I PsA ${s R
Zt AZ t As {B 8 {st B8stIB Zt AB I 8BR k s8}j$stIB R$8}j 8 t {sIs Zts I RZR }s R d(( % { R 8? sR ]ZstIB sZ8 t s j s8sK tB sARBjZ B I {ZsjJZ$ {BRs Ysk JZ 7$t 8As B tB R$ 8} jBR {BtR Z{ B R Yst
$t BIZ{$ t j I$R K tB {s8A$BR RZAR st{$sj R t$IB t {Z t s R BR
I sjj R
O R B $t{jZRB t P {YsR js $%s8 t {$ t R et Zts ? }B{s
t JZ j 8BI js` I As {BR s? Zt R Ys{? s I 8st s $t Z$ $%s Zt B t j I$R K tB I j 8skB AZJZ I j? t s stRB{ ? st${s I RZ $ 8}B j }BR$A$j$IsI R I j 8sR BI? Bt ${B ts%? B
p s esR t
wR$ jB y D I$B sj sR {Bt jsR
_ R s R s IB sIB I Z IsR I }sj sR Zts Y? j${ k
% jsR sZ-$j$s R RZ s8sK tB s -{ R$%B }s s js }B t{$s JZ I Rs BjjsAsU s st j t B JZ tB tI? s jB RZh{$ t }s s {BR s j {B8AZR $Aj JZ {BtRZ8? s ! B stRs j? st ${B Ps8BRB j
q$ st${ $tR$ t$s I j } B RB 8sJZ$t$R s JZ %$%? s j 8ZtIB I Rs BjjsIB s } $t{$}$BR I R$ jB k R ? 8ABjB I Zts ? }B{s t JZ jsR 8? sJZ$tsR 8} 9sAst s $t%sI$ jB BIB RZP $? B j tsZP s $B 8? sR Bt {? j A I js Y$R B $s w {$ t 8 t { sIB t js RZ} } BIZ{{$?
q$ st${
>d HD Ns tB{Y
I j d; I sA $j I d d1 8$ t sR ts% sAs t %$s` $tsZ Z sj t s ZsR I j V j? st ${B j {sR{B I j As {B B9? B Ps sj8 t {Bt js }s RZ8 $Is I Zts tB 8 8Bt sK ts I Y$ jB "gV ? sR
BIs k {sK ts s AsAB " YsA? s B I tsIB j Bh{$sj I Zs I$s {ZstIB PZ s%$R sIB j ${ A s 8 tBR I E(( 8 t Zt $t t B I R R} sIB I RB s j } j$ B qBIB PZ $t? Z $j eR $8}BR$Aj I t t st {B B R}s{$B s Zt As {B I ;E ((( Bt jsIsR I R}js9? stIBR s ZtBR ;( ,8 Y wjs
>
_B B B jsIB jBR stI R I$h{$BR RBt 8? sR RA j BR k R $j$9sIBR t RZR } B}B {$Bt R JZ jBR I$h{$BR 8? sR } JZ K tBR _B ` 8}jB js AsR I Zt sR{s{$ jBR R t {B8}s s{$? Bt 8? sR R {Ys JZ js I Zts {sRs ]B8B R K tsjs j s JZ$ { B i Bt R sR I$P t{$sR t js PB 8s BA I { t s JZ $8$ t BR I PZt{$Btsj$IsIU t jsR {sRsR R I R sAj JZ j 8skB t? Z8 B }BR$Aj I jsR YsA$ s{$Bt R t s %$R sR sj - $B jB {Zsj %$ t s $t{ 8 t s js RZ} h{$ I js }jst s -
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
xn
$t {$s 5 {Z Ist2D
*BR YB sR k 8 I$s I R}Z? R j As {B R $As s }$JZ R$t 8 I$B
et
j {? Z8ZjB I I RsPB ZtsIsR {$ {ZtR st{$sR JZ B $ $ts Bt js {s ? sR BP sj R {B8B Zt }$jB s` 8 s $B s BIs 8? sJZ$ts IZ st js tB{Y t Zts 9Bts {Bt } R t{$s I ${ A R {sA I R s{s {B8B {sZRs Z ? j $8s I j YZtI$8$ t B js }BA 9s k 8sjs {sj$IsI I j s{ B 8}j sIB t js {BtR Z{{$? Bt I j AZJZ t {Bt sR {Bt j jZ`B k BR t s{$? Bt {Bt JZ PZ Bt PsA ${sIBR jBR {s8s B R k jsR RsjsR I { B }s s j }sRs` wI } $8 s {js BD 7 ? Zt }s { js sj s{$? Bt
I s{ B I As`s {sj$IsI 8}j sIs }BI ? s YsA R %$R B 8Zk sP { sIs }B js ts% s{$? Bt t s ZsR Y jsIsR -} $8 t stIB Zts 8 8s t RZ R$R t{$s ejjB YsA ? s } B}${$sIB j ? s}$IB
YZtI$8$ t B I j As {B sR js {Bj$R$? Bt 7 { JZ Zt s{ B I 8 `B {sj$IsI sZtJZ tB YZA$ R %$ sIB j s{{$I t IsIsR jsR {$ {ZtR st{$sR t JZ ? R R } BIZ`B R ? }BI ? s YsA sRsIB j YZtI$8$ t B IstIB $ 8}B sj }sRs` }s s sAstIBts j AZJZ ]Bt RZR 1E 8 I RjB s
wR? BjB nd 8 8 tBR JZ js B e$& jD PZ Zts I jsR 8skB R {BtR Z{{$Bt R I js ? }B{s yt{jZRB Zts I jsR {Y$8 t sR s PsjRs R %? s RBjs8 t {B8B B I % t $js{$? Bt k skZIsAs s Is j Zt s$ 8? sR 8s` R ZBRB $8}Bt t ]s ? sR BP R {$ t R {B8B js I j stRAB IsIB R}s{$sj tB s8 ${stB
]Ysjj t
t d ME R s{Ys{st s8A$? t s PsjjBR tB st B 8 {? st${BR R$tB I
{BtR Z{{$? Bt I j $t t$B
O R JZ Rsj%stIB jsR I$R st{$sR }s { {Z8}j$ R sJZ j {BtB{$IB
sPB $R8BU "_B Zt {js%B R } I$? B Zts Y sIZ s }B Zt Y sIZ s R } I$? B Zt {sAsjjB "
]Bt jB I${YB s 8 tBR JZ R I R{ZA st tZ %BR 8s $sj R I {BtR Z{{$? Bt 8? sR R$R t R JZ j s{ B k j YB 8$ ? Bt B R s%st{ 8? sR t jsR ? {t${sR I I$R K tB I$P? {$j8 t R jB s ? st {BtR Z$ sR{s{$ jBR {B8B jsR
8BtZ A
I n ,8 I sj Z s I R{ $ sR }B iBA 7$j% A }B
8Z{YB JZ R Ysks s%st9sIB t s JZ$ { Z s $t t$ ? s I js {BtR Z{{$? Bt t j R$ jB yz _B j 8B8 t B j R YZ8stB tB Ys {BtR Z$IB tsIs JZ 8$Is Zt ,$j? B8 B I RI js AsR YsR s js {? ZR}$I NsR B R 8 jsR I _ BtsR I Zsjs NZ8}Z js {s}$ sj I sjsR$s
{BtR Z$IsR {$ t 8 t BR t st t js s{ Zsj$IsI j } $%$j $B I R jBR I$h{$BR 8? sR sj BR I j 8ZtIB ]Bt RZR MM }jst sR RBt IBR I$h{$BR 8 jBR {Bt { sIBR }B Zt }Z t s? B t jBR }$RBR ;d k ;1 JZ R sj9st $8}Bt t R YsR s jBR ;xd, 8 z IsI sR $RjsR t j {$ jB {sIs Zts I RZR AsR R t PB 8s I R jjs B{Z}s Zts RZ} h{$ I 1dn! x( 8
w j JZ$%sj t s x(
${s t j } Bk { B I I$h{$BR I st sj Z s R j sZ8 t B {s8}BR I P? Z ABjD Ns 8s t$ ZI { ? I js RZ} h{$ -}Z R s sj %$ t BU IZ}j${s js sj Z s JZ$%sj s 8Zj $}j${s }B dE j P { B I jsR BR{$js{$Bt R js sj R I j I$h{$B {sZRsIsR }B j %$ t B R$ tB R sZ8 t s js $ $I 9 I js R Z{ Z s _s s IZ{$ R P { B R sR 8 s R Z{ Z sR s{BR Z8A st s I$R K ts R t PB 8s I YZRB } B R$%B Ys{$s js {$8s
e-$R t sI 8? sR B BR } BAj 8sR ? {t${BR tB 8 tBR $8}B st R
7Bt t { Rs $sR AB8AsR ? sR sjj? s
}BI BRsR }s s RZA$ j s Zs I RI js AsR I j I$h{$B YsR s jBR }$RBR RZ} $B R
I jBR n( 8 I sj Z s js - $t{$? Bt I $t{ tI$BR k js %s{Zs{$? Bt I } RBtsR 8 I$st {B{Y R I AB8A BR {Bt R{sj s RZj s $8}BR$Aj ej ZRB I YB 8$ ? Bt I sj s R$R t{$s I tZ %BR s{ BR R$R t R k jsR s8}j$sR {$8 t s{$Bt R JZ BAj$ st s JZ R sR 8 s R Z{ Z sR B{ZT } t %s $sR 8st9stsR RBt sj ZtBR I jBR JZ $8$ t BR ? {t${BR t { Rs $BR }s s j %st s sj R 8Bj R JZ B9st jBR j ? 8$ R I jsR }BR$A$j$IsI R s{ Zsj R qsj % 9 js j tIs $s
qB I sA j
tB PZ R sAstIBtsIs }B RZR s B st R {BtR Z{ B R st js $8}BR$A$j$IsI I t tI$8$ t B {sZRsIs }B js $t % t{$? Bt I$%$ts R$tB JZ R$8}j 8 t sj{st9? B j j? 8$ I js R$R t{$s I jBR 8s $sj R {Bt JZ R {BtR Zk? B RZ AsR
© Los autores, 2001; © Edicions UPC, 2001.
x;
* $t Bt s e$tR $t
et js h{{$? Bt t{Bt s8BR s8A$? t B sR RBjZ{$Bt R tB 8 tBR RB } tI t R =tsR h{ ${$sR {B8B jBR I$h{$BR I R{ $ BR t js tB% js ZtIB st$jjB >i$t bB jI d (H I Ns k W$% t _BR t ZjB 1D jB JZ j R } 8$ 8st t R 4B stIB RZR } B}$BR t sIB R st $ s%$ s B $BR w]s}? }B t{$8s I js R? Bj$Is {B 9s I RZ 8ZtIB s $h{$sj ? BIB $I? Bt B }s s j$8$ts jsR R ZtIsR R$I t{$sRU j AjBJZ I }$RBR }Z I sRjsIs R s %BjZt sI sj jZ s 8? sR {Bt% t$ t w{js B R ? s JZ }s s jjB Ysk JZ {Bt s {Bt Zts {B8Zt$IsI I % {$tBR A$ t s% t$IsD ! s }BR$A$j$IsI RBt jBR M( t$% j R {BtR Z$IBR }s s sjB`s js 8sJZ$ts $s I js - $t s s9s sj$ t? ts , jj YsA$ st I j }jst s Vj s$ yz I _jst s } BY$A$IB >3B A$II t _jst d xEH JZ R - $ tI t As`B $ s YsR s Zts } BPZtI$IsI I 1( 8$jjsR WB 8BR I }sRB JZ R Is B R {Bt sI${ B $B et ZtB I jBR I$? sjB BR R I${ JZ js 8sJZ$ts $s , jj k jsR }jst sR I t ? s B{Z}st Zt {ZAB I 1( 8$jjsR I jsIB R I {$ 1( 1( 1( ) M!((( 8$jjsR {? ZA${sR wZtBR n1!M(( ,8n D et B B R R K tsjs JZ js st 8? sJZ$ts BA $ t RZ t ? s I 1(( s{ B R 8BtZ{j s R t sIBR s Zts } BPZtI$IsI I x( 8$jjsR 5et JZ? JZ Is8BR R K tB Z$Bt$R s2 eR s RBjZ{$? Bt I {BtR Z$ jBR I$h{$BR Ys{$s jsR t sK tsR I js q$ s s8A$? t R Z $j$9sIs t j hj8 3B sj 9s $tP tsj >3B RR d 1H et R {sRB R s s I Zts } $R$? Bt I sj s R Z $IsI Ns {BtR$ ts }BI ? s R U R$ {BtR Z$ Ys{$s s $As $ t RZR j$8$ s{$Bt R k I jB JZ R s s R I 8$t$8$9s j R}s{$B I$R}Bt$Aj RBA js RZ} h{$ R }Z R Ys ? s8BRjB Ys{$s sAs`B * B} s }B R s sj ts $%s Ysk JZ t t {Z t s R$t 8As B JZ js 8} s Z s sZ8 t s ZjB xD s 8 I$Is JZ I R{ tI 8BR Ys{$s jsR } BPZtI$IsI R R R w{B8B % 8BR t j {s}? et Z ?j $8B - 8B R$ 8} }Z I {Z $ R s ZtBR AZ tBR s JZ$ { BR sZtJZ R st I B $ t - s R et js } j? {Zjs 7 s s >d EH R R} {Zjs {Bt js }BR$A$j$IsI I JZ jsR 8s t? h{sR }$ ? s8$I R I j zsjj I p$9 Y t e $} B PZ st {BtR Z$IsR }B Zts s9s sj$ t? ts JZ %$R$ ? B js q$ s Ys{ ZtBR {Zst BR 8$j R I sK tBR Ns R$8ABjB ? s I js 8$ BjB ? s $}{$s st $ Zs R ? s Zts } R t s{$? Bt sj ? B ${s I R BR $jZR R %$R$ st R eI$h{sIs Ys{$s j sK tB 1E(( st R I ] $R B js }$ ? s8$I I j Ps s? Bt B}R {Bt RZR 1 E 8$jjBt R I AjBJZ R }? BR I ZtsR 1 x Bt jsIsR {sIs ZtB k Zts sj Z s I d;E 8 R % js {B8B Zts I jsR 8? sR $8} R$Btst R BA sR s JZ$ { ? Bt${sR {BtR Z$IsR }B j YB8A eR js Z ?t${s I jsR 7$ 8s s%$jjsR I j 8ZtIB st $ ZB JZ } 8st { s? Zt t }$ _ R s JZ sj ZtsR %B{ R Yst JZ $IB % t js {BtR Z{{$? Bt s I js ? }B{s I jsR }$ ? s8$I R Zts 8stB tB YZ8sts PZ Bt R$t jZ s s IZIsR js {tBjB ? wZRB I s8}sR { D k Zts sAZtIst 8stB I BA s jBR s ? h{ R I R 8$j ts $B 8BtZ8 t B R? 8ABjB I j }BI I Zt Ps s? Bt JZ R {BtR$I sAs s R? 8$R8B {B8B j I$BR I RZ }Z AjB et } j? {ZjsR {B8B <st s dM >d M(H k t js {BtB{$Is 1((d Zts BI$R s I j R}s{$B >1((dU V 7}s{ !IkRR k d EMH R }$ j 8s I Zts $t % t{$? Bt sj$ t? ts t j }sRsIB JZ YsA ? s $t4Z$IB t j I Rs BjjB I js YZ8st$IsI ]BtR Z$ R{ ts $BR sj$R sR }s s 8ZtIBR h{ ${$BR B $8s $ts $BR JZ$ s8A$? t B8s t {BtR$I s{$? Bt jsR j k R I R{sjs JZ % t$8BR {B8 t stIB 5* 8sR$sIB sAs`B }s s jBR
i? BR I $t s R$ Z t {B $ tIB RBA j 8s I jBR st $ ZBR sR BtsZ sR t jsR }ZAj${s{$Bt R }R ZIB{$ t ? h{sR }s s I j${$s I jBR s8st R I R sR Pst sR? sR ws jsR JZ {sA s s t B sR jBR I$AZ`BR B8? ${BR I js Z$tsR I Ws9{s t _ ? Z B jsR R{Zj Z sR t }$ I s I js yRjs I _sR{ZsD k tB sABtsIB }s s R} {ZjsIB R I BIs sj s g+Z? }B{s {Bthst9s }s { t t R sR } RBtsR t js {s}s{$IsI YZ8sts }s s t JZ {Z $ s js $t % t{$? Bt - s R
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
NN
3$ d d1 =ts $ st R{s Z A I j sK tB 1((( js {$ZIsI I ? B}Bj$R 7Z s}s t BR t BR$IsI B{Zj s jsR }s sIB`sR I Zt } B RB {tBj? B ${B JZ R? BjB A t h{$s s ZtBR }B{BRU Zts }BAjs{$? Bt RZA ? st s PZtIs8 t sjT 8 t I BA BR 8st $ t jsR 8? sJZ$tsR JZ } B}B {$Btst t ? s s js {$ZIsI 8$ t sR JZ t js RZ} h{$ %$% Zts ? j$ BI sIs I jZ`B k R}j tIB * j hj8 ? B}Bj$R > B}Bj$R d 1EH ? 8} BABR Z$Bt$R sR k {BtR Z{ B R I R{ ts $BR k I {B sIBR2 z s8BR {? B8B Ps{$j$ s j R js s s NsR 8Bt sK tsR I js q$ s tB RZ} st js j %s{$? Bt I M, M ,8 I j 8Bt e% R t js {B I$jj s I j <$8sjsks _BI 8BR } Zt s tBR R$ s8A$? t -$R Zt j? 8$ }s s RZ sj Z s _s s R$8}j$h{s RZ}B s8BR JZ Zts 8Bt sK ts R Zt AjBJZ I I$? B-$IB I R$j${$B JZ } 8st { t{$8s I Zts RZ} h{$ }jsts I j 8$R8B 8s $sj Ns sj Z s I js 8Bt sK ts I } tI ? s I js {s}s{$IsI I RB}B JZ t s RZ AsR ej %sjB 8? s-$8B R sj{st9s {ZstIB j 8s $sj I js AsR $t{s}s9 I RB}B s 8? sR } RB 8}$ 9s s PZtI$ R 7 s s I Zts {B8} ${$? Bt t IBR P { BRU js PZ 9s I js s% IsI }B Zt jsIB k js $ $I 9 I j 8s $sj }B B B ]Bt R 8BI jB }Z I BA t R Zts {B s RZ} $B }s s js sj Z s 8? s-$8s JZ }Z I t t 8Bt sK tsR I jsR 8$R8sR {s s{ ? R ${sR t Zt }jst s I s% IsI h`sIs _s s js sj Z s I jsR 8Bt sK tsR R R R ? s I dx ,8 %sjB s9BtsAj R$ R $ t t {Z t s js R$8}j${$IsI I j 8BI jB ej T RZj sIB R} sIB }s s jsR 8Bt sK tsR I Zt }jst s {B8B Vj s$ yz RZ}Z R s8 t {BtR $ Z$IsR }B Zt 8s $sj I {s s{ ? R ${sR R$8$js R sj R k jZ s IBtI R I Rs Bjjs js s{{$? Bt I j hj8 _jst s } BY$A$IB R ? s I ZtBR d ,8 NsR {B I$jj sR 8Bt sK tBRsR I R }jst s I h{{$? Bt R ? st 8? sR j %sIsR JZ jsR R R {B8B R ? s I R} s t Zt jZ s I 8 tB Zt {B8 t st jBR -} I${$Bts $BR s RZ jj sIs sj s% IsI w(, M % { R js s% IsI R R ? }jst sD et <Z %B I * s ? Bt j h{ ${$B YB s ts sj I jBR {Y js I js tB% js YB8? Bt$8s I
© Los autores, 2001; © Edicions UPC, 2001.
N-
* $t Bt s e$tR $t
3$ d dn g7$ R JZ ks jB I {? s kB t? s8BR JZ YsA Z $j$9sIB 8s $sj R I } $8 s {sj$IsI
iBA 3B bs I js - sB I$ts $s s% IsI } 8$ R? BjB R Z{ Z sR JZ tB RBA }sR t jBR dx 88 I sj Z s ej }jst s s {Bt Zts s% IsI I s} tsR ( nM js R sjA s js PB 8s{$? Bt B{BRs 8? sR sj s I j 7$R 8s 7Bjs U j !jk8}ZR BtR Zt $8} R$Btst %Bj{? st I 1; ,8 I sj Z s w t {B8}s s{$? Bt j 8skB %Bj{? st I js q$ s j sZts NBs t jsR yRjsR <sbs$ R sj9s $8}Bt t s ZtBR 8BI R BR M ,8 I sj Z s RBA j t$% j I j 8s D ,
V }B{B JZ Ysks8BR BAR %sIB js s}s $ t{$s I jsR {BRsR JZ tBR BI st B Ysks8BR %$R B PB B sP? sR I BA` BR sR Bt? B8${BR tBR YsA 8BR IsIB {Z t s s8A$? t I JZ js PB 8s I jsR B{sR B I jsR 8Bt sK tsR R {s} ${YBRs 8$ t sR JZ js I BA` BR 8Z{YB 8skB R {B8B jBR }jst sR R ? s A$ t I ht$Is NsR PZ 9sR s%$ s B $sR RBt I? A$j R s } JZ K ts R{sjs wjsR I$R st{$sR RBt } JZ K tsR sZtJZ s8A$? t jB RBt jsR 8sRsR $t%BjZ{ sIsRD } B s {sZRs I RZ {s ? s{ R$ 8} s s{ $%B RZ P { B R s{Z8Zjs k jj st s IB8$ts s st R{sjs RBA js B s PZ 9s $8}B st t tZ R B 8ZtIB 8s{ BR{? B}${BU js PZ 9s j? { ${s e-$R Zt s8sK tB { ? ${B }B t{$8s I j {Zsj jsR } $8 sR } IB8$tst RBA jsR R ZtIsR Ns PB 8s I js }$ I sR B I jBR }jst sR R}BtI s R Y {YB Ns I$8 tR$? Bt R R$ ? Zs t jBR d( k jBR d(( ,8 k {B R}BtI sj I$? s8 B I Zt } JZ K tB sR B$I _B I As`B I R s sjjs j {Z }B $ t Zts {BY R$? Bt I B $ t j? { ${B k }Z I sIB} s {ZsjJZ$ PB 8sU }$ I sR B{sR $t{jZRB 8Bt sK tsR } R t st PB 8sR $ Zjs R _B t{$8s js {BY R$? Bt R I B $ t s%$ s B $B k j {Z }B $ tI s sIB} s Zts PB 8s RP? ${s {B8B jBR }jst sR k jsR R jjsR et js tB% js I V YZ ] ]js , NsR PZ t R I j }s s? RB >qY 3BZt s$tR BP _s sI$R d H Zt ? P ${s s s%? Ps8BRB $t t$ B Ys R$IB {s}s9 I tI Zt }Z t t eZ B}s k V R I j R {YB I p$A sj s *BR B R 8 jsR % IsI sR B R I <? {Zj R R$ ZsIsR Zts P t s B s t dx ,8 I R}s{$B %s{? B RBR $ t t js R Z{ Z s s n ,8 }B t{$8s I jsR s ZsR IBtI {Bt4Zk t j I$ ? st B k j V j? st ${B WB {Bt t B {Bt R B sAB Is ? s Zt } Bk { B s8A$? t
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
N
{BjBRsjU {BtR Z$ Zt sR{ tRB JZ Zts js RZ} h{$ R {Bt Zt Rs ? j$ R$ ZsIB t B ? A$ s B R s{$Bts $s s ZtBR nE!((( ,8 w]s}? ZjB 1D i sj8 t Zts {BjZ8ts B Zt {sAj tB }Z I t {ZsjJZ$ sj Z s B jBt $ ZI }s s Zt BRB I 8$tsIB Ns R sA$j$IsI I Zts {BjZ8ts % ${sj I } tI I jsR } B}$ IsI R j? sR ${sR I j 8s $sj I RZ I tR$IsI k I RZ I$? s8 B _B ` 8}jB Zts {BjZ8ts I s{ B I x 8 I I$? s8 B tI ? s Zts sj Z s 8? s-$8s I ZtBR ;(( 8 8$ t sR JZ Zts I 8sI s IZ s k Zt$PB 8 I j 8$R8B I$? s8 B s} tsR sj{st9s ? s jBR n(( 8 wjs R {Bks $ st Zt s ? ABj I jBR ABRJZ R I ]sj$PB t$s }Z I jj s YsR s sj Z sR I dd( 8 k }BR Zt Bt{B I ZtBR d( 8 I I$? s8 BD _s s {BjZ8tsR {BtR Z$IsR {Bt j 8$R8B $}B I 8s $sj js I } tI t{$s I js sj Z s I js {BjZ8ts {Bt j BRB R $I? t ${s s js JZ } R t st jsR R Z{ Z sR B ?R sR I jBR st$8sj RU j {ZAB I RZ sj Z s R } B}B {$Btsj sj {ZsI sIB I RZ I$? s8 B =t s ? ABj {B8B Zt Bj$%B sj{st9s Zt %sjB $tP $B sj JZ R BA tI ? s }s s js sj Z s I Zts {BjZ8ts I BRB Zt$PB 8 et {s8A$B s ? ABj R {B8B j sA B }Z I t t s8sK tBR RZ} $B R s jBR I js {BjZ8ts % ${sj {B R}BtI$ t ejjB R I A s js PB 8s I j s ? ABjU j Bj$%B {Bt{ t s js 8skB }s I RZ 8sRs j `BR I j RZ jB k }B st B RZ R Z{ Z s R 8? sR M $t R sAj JZ js I Zt sA B {Zks 8sRs R t{Z t s 8? sR { {s I RZ AsR Vj $ Zsj JZ R K tsj? sAs8BR t j {sRB I jBR I$h{$BR I st sj Z s s tB R JZ R I$R}Bt s I Zt 8s $sj I {s s{ ? R ${sR I$P t R I$P? {$j8 t }BI ? st {BtR Z$ R {BjZ8tsR 8? sR sjj? s I Zts {$ s sj Z s ]js B JZ t js tB% js ]js , s%st9s Y? sA$j8 t js -$R t{$s I ZtBR 8s $sj R RZ} R$R t R I tB8$tsIBR Y$} hjs8 t BR _ BAj 8s RZ j B V Psj s I j 8$R8B t js sj$IsI $t t$ BR k s JZ$ { BR Yst I Rs BjjsIB RZ $t t$B }s s jj %s s {sAB BA sR I $t t$ ? s {$%$j {BjBRsj R et js s{ Zsj$IsI j 8skB }Z t {Bj st I j 8ZtIB R j I V,sRY$ s$,kB JZ {Bt { s js $Rjs I 7Y$,B,Z {Bt Fs}? Bt q$ t Zts jBt $ ZI I n! d( 8 k Zts jZ9 { t sj I {sR$ 1 ,8 eR ? s RBR t$IB }B IBR B R I 1Mn 8 I sj Z s % IsI BR sR{s{$ jBR I d(( 81 I }jst s *BR Z RBR {sAj R 8st $ t t js R Z{ Z s I j }Z t RZ` s s R sR B R ]sIs {sAj R ? s PB 8sIB }B Zt t9sIB I 1 ( {B IBt R {sIs ZtB I jBR {Zsj R {Bt $ t s RZ % 9 d1 sjs8A R I Zts sj s{$? Bt I s{ B {Bt R$j${$B ]sIs 8$j? 8 B {ZsI sIB BtD ]Bt j sjs8A 8}j sIB I {sAj R {s}s9 I RBR t dM( , w R$R t{$s s js s{{$? }BI ? st Is R 8? sR I %Z j sR s js q$ s 7 t{Z t s t } Bk { B j }Z t I R$ts JZ Zt$ ? s 7${$j$s {Bt y sj$s t j sK tB 1((E {Zks jZ9 { t sj R ? s I n, n ,8 _BI 8BR RZ8$ jsR $I sR YsR s sJZ? -}Z R sR {Bt jsR }sjsA sR I j } B}$B psj$j BU "_B jB JZ ks R Ys I 8BR sIB }BI 8BR % {js s8 t js $8}BR$A$j$IsI I $t{ 8 t s j s8sK tB I jsR {BtR Z{{$Bt R I j s B I js ts Z sj 9s YsR s jj s s I$8 tR$Bt R $tht$ sR Vt? sjB s8 t R }Z I % js $8}BR$A$j$IsI I {BtR Z$ As {BR }sjs{$BR B $ j R$sR I stI R } B}B {$Bt R I 8st s JZ RZR 8BR }s $BR %$ sR }$ 9sR I Y$ B k t RZ8 t BIsR jsR }s R R st R R 8st t st `Zt sR W$ js ts Z sj 9s }Z I {BtR Z$ s ? ABj R I s8sK tB - sB I$ts $B }B JZ RZR s8sR R B8} ? st As`B RZ } B}$B } RB VR? R ? s s8A$? t $8}BR$Aj PB 9s jsR R Z{ Z sR BR sR I j YB8A I jBR {sAsjjBR k I jBR B BR st$8sj R I 8st s JZ R 8st Z%$ R t `Zt sR ?
Ns t { R$IsI I B} $8$9s js jZ9 RBjs }s s sj$9s js PB BR? t R$R I 8$ts js PB 8s I jsR {B}sR I jBR s ? ABj R et jBR ABRJZ R B}${sj R $ t t PB 8sR s}jstsIsR }Z R B JZ jBR skBR jZ8$tBRBR $t{$I t % ${sj8 t et {s8A$B t jBR ABRJZ R AB sj R IBtI js $t{$I t{$s I js sI$s{$? Bt jZ8$tBRs R 8? sR sRst jsR {B}sR I jBR s ? ABj R sIB} st PB 8sR {? Bt${sR w{B8B jBR sA BRD et {$ B R t $IB js jZ9 8BjI s RZ PB 8s
M
© Los autores, 2001; © Edicions UPC, 2001.
NM
* $t Bt s e$tR $t
k {Z8}j$ R t RZR PZt{$Bt R tB 8sj R R$ R BR st$8sj R Z%$ R t JZ $t{ 8 t s RZR sj Z sR }B JZ R $t{ 8 t B I sj Z s R {BtR Z$ ? s R? BjB Z $j$9stIB Zt 8s $sj 8Z{YB 8? sR IZ B k PZ JZ j ZRZsj B sZ8 t stIB j s8sK tB I RZR YZ RBR k {s8A$stIB I R s 8st s RZ h Z s YsR s JZ js PB 8s k js s}s $ t{$s I jBR st$8sj R RZ $ $ R t Zts 8BtR ZBR$IsI qsj % 9 PZ R R B jB JZ } tRsAs tZ R B }B s {ZstIB sj I R{ $A$ s Zt tB 8 $ st I {? sU
eR $8}BR$Aj {sj{Zjs RZ sj Z s * 8st s JZ RZ s8sK tB -{ I {ZsjJZ$ 8 RZ s "
? sJZ$tsR }s s YB 8$ sR 7$ sAstIBts8BR R sR R Z{ Z sR {BjBRsj R }s s sI t s tBR t jsR tB 8 tBR RB } tI t R { s{$Bt R YZ8stsR I jB 8Zk } JZ K tB tBR B}s 8BR t R Z$Is {Bt js 8${ B j { ? Bt${s ej $tB I jB I$8$tZ B R ? s IB8$tsIB }B Rs {tBjB ? s JZ tB I `s I RB } tI tBR {Bt $T tZs8 t k JZ R js R t{$s I 8Z{YBR I jBR I$R}BR$ $%BR st {B8Zt R YBk t I? s {B8B jBR B I tsIB R B jBR j { BIB8? R ${BR ]B8}Bt t R j { ? Bt${BR {B8B jBR stR$R B R sj{st9st ks js R{sjs 8${ B8? ${s R I {$ js 8$jjBt? R$8s I 8 BU d( - 8 $j R I jjBR R $8}jst st RBA js RZ} h{$ I Zts 8$t? ZR{Zjs js8$t$jjs I R$j${$B {BtR $ Zk tIB jsR }sR $jjsR B 8${ B{Y$}RU jBR % IsI BR { A BR B {B s9Bt R I jBR B I tsIB R O js {s s }B js 8$t$s Z $9s{$? Bt R ? s s? Zt I Rs Bjj? stIBR FZt B s R s 8${ B {tBjB ? s j { ? Bt${s R ? s js 8${ B8 {? st${s s? Zt $t{$}$ t JZ R sPsts }B I Rs Bjjs 8? sJZ$tsR I$8$tZ sR 7 Yst PsA ${sIB ks 8${ B8B B R }j${sR 8$t$s Z $9sIsR I jsR sR}sR I Zt 8Bj$tBD I dn( 8${ ? B8 BR I I$? s8 B {Bt B B w ? 7? Yst j ? IB A$ t dn( d( - 8 R I {$ Zts I? {$8s I 8$j? 8 B =ts I { ts I R sR 8? sJZ$tsR {sA ? s t j $t $B I js j s B NsR s}j${s{$Bt R } %$R sR sj R {B8B }$t9sR 8${ BR{? B}${sR RBtIsR }s s js I {{$? Bt I R K tsj R t %$BRsR Zts % 9 sjB`sIsR t j { A B }? jIB sR $t j$ t R JZ $tk { st IBR$R sI {ZsIsR I 8 I${s8 t BR t j {Z }B I Zt }s{$ t { }s { t 8? sR } B}$sR I js h{{$? Bt _s s R $8Zjs s? Zt 8? sR RBR RZ K tBR JZ Z? st j I Rs BjjB {tBj? B ${B j $tPB 8? s ${B e ${ * -j RZ $ $? B t d E js }BR$A$j$IsI I Is Zt Rsj B {Zst $ s $%B sj {Bt 8}js 8? sJZ$tsR I j s8sK tB I 8Bj? {ZjsR eR I {$ I 8} 9s s } tRs t js tstB {tBjB ? s jj stIB sj sJZ$tsR JZ }BI ? st sAs`s B I t I 8s t$ ZI I js 8$j 8$jjBt? R$8s I 8 B d( 8 ? I$ { s8 t RBA jBR s ? B8BR * -j $8s $ts RZA8s $tBR I s8sK tB tstB8? ${B w{B8B j st I t B RZA8s $tB _ B ZR I z$s` sjZ{$tst D {Bt BjsIBR }B tstBB I tsIB R JZ {sA ? I jBR s{ Zsj R stR$R B R I R$j${$B JZ %$s`s ? st }B j B t Rst Z? t B Z $j$9stIB {B8B {B8AZR $Aj j B-? tB k js jZ{BRs I js Rst w t Zt } B{ RB R$8$js sj R Z$IB }B jsR 8$ B{BtI $sR jsR P? sA ${sR I } BIZ{{$? Bt t ? ${s I jsR {? jZjsRD _BI ? st I R Z$ %$ ZR j$8$ts I }? BR$ BR I sRs I j R$R 8s {$ {Zjs B $B sj$9s $t % t{$Bt R JZ$ ? Z ${sR jB{sj R R${s i${Ys I _ 3 kt8st t 9BtsR I j${sIsR w{B8B j { A BD et d x j } 8$B WBA j I P? wd dMTd MMD $8s $tsAs Zts RZ{ R$? Bt I 8? sJZ$tsR } B R$%s8 t 8? sR } JZ K tsR JZ R ? st {s}s{ R I PsA ${s s B sR I R{sjs $tP $B qsj % 9 }BI ? s R ? R s js %? s }s s {BtR Z$ R BR I$8$tZ BR $t t$BR V R sR R{sjsR }s { JZ js $t% R $ s{$? Bt {$ t ? h{s %s }B I jst I js $8s $ts{$? Bt I js {$ t{$s h{{$? Bt }Z R B JZ }B{BR RBt jBR sZ B R k Z$Bt$R sR JZ R Yst s{ {sIB sj 8s {B8B
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
N
sj sZtJZ t sj ZtsR BA sR I {$ t Ps{ Z s js tstB {tBjB ? s PB 8s ks }s $t st I j sRPBtIB {tBj? B ${B I j PZ Z B et j js B V YZ ] ]js , I R{ $A j ZRB I R $}B I {tBjB ? s t js PsA ${s{$? Bt I Y s8$ t sR }s s
NBR } ? B-$8BR $tJZ$j$tBR >qY W - q tst R d xEH s Ys sAB IsIB j
Zts {BjBt$s I 8$ sR s jsR JZ } B R$%s8 t R jsR IB s I js }sjst{s k I j $t B Y {YB JZ }Bt t {Z R $? Bt j j$I s9 B I js R} {$ YZ8sts qs8A$? t p 8s t RZ tB% js
? ZR${s t js Rst >+Z t BP Vt jR d (H
et jjs R ts st jBR } BAj 8sR
I Zt {$ t ? h{B JZ Z $j$9s I Zts PB 8s $j? {$ s Zts {tBjB ? s AsRsIs t
{Y$}R A$Bj? B ${BR }s s
stRPB 8s jsR 8Bj? {ZjsR I *WV I RZ B st$R8B t {B8}Z sIB R A$Bj? B ${BR Ns s}s ${$? Bt I 8$j R I 8$jjs R I } JZ K tsR {Bt{$ t{$sR t RZ $t $B Zt Zt$% RB I $t j$ t{$sR I t B I R? } 8$ t sj sZ B R} {Zjs RBA j Y {YB I JZ jBR R R YZ8stBR RBt 8? sR I$P? {$j R I I R{ $A$ JZ js P? R${s B js {$ t{$s JZ jjBR 8$R8BR I Rs Bjjst et j 8$R8B p
s R 8Z % > B%$t s R d nH WstBI s8R >d xH {$ t
s $t BIZ{ ZtBR 8${ B BAB R JZ RBt Z $j$9sIBR }s s sIs} s j {Z }B
YZ8stB s js %$Is t s et ZtB I jBR js BR JZ s}s { t
{B}$js{$? Bt I "tstBY$R B $sR" I j I$ B ej Bt ejj$B R YsAjs I j I Rs BjjB I tstB8? sJZ$tsR {s}s{ R I }s s jBR `$IBR YZ8stBR j R$BtsIBR }B Zts Asjs Ns tstB {tBjB ? s IB8$ts js {BtB8? s I j _ $8 ZtIB t Zts q$ s I Zt PZ Z B { {stB t _ s{ d H I FB <sjI 8st Ns
_s9 $t 8$tsAj >3B % tstBP s Zs Zts 8? sJZ$tsT}s sT BIB } 8$ { s {ZsjJZ$
I$R}BR$ $%B s }s $ I 8s $sR } $8sR ej _ $8 ZtIB R? BjB } 8$ JZ R s $jZ $B Rsj s I RZR P Bt sR Ys{$s }s? R R I j q { ZtIB s {s8A$B I JZ ? R BR s{{ Ist s Zts }Bj? ${s BA I$ t k s8$R BRs et R sR {BtI${$Bt R j {Bt4${ B R ? s R %$IB
ej YB8A Ys R$IB {s}s9 I {BtR Z$ }Z t R I$h{$BR k As {BR I stI R I$8 tR$Bt R O {B8T }Bt t R j { ? Bt${BR k 8 {? st${BR - sB I$ts $s8 t } JZ K tBR 8 { I s js 8${ B {tBjB ? s k } Bt B ks s js tstB {tBjB ? s qBIBR jjBR R$t 8As B j `BR I t I$8 tR$Bt R JZ R st 8? sR I I$ 9 B {$ t 8$j % { R 8? sR stI R B 8? sR } JZ K tBR JZ RZ } B}$B s8sK tB WZ %BR 8s $sj R tZ %sR {tBjB ? sR tZ %BR s%st{ R {$ t ? h{BR t I ht$ $%s } 8$ $ ? st RBA }sRs R sR {B sR ej PZ Z B Ys ? s JZ js {Bt% $ R t {B $I$sts sj$IsI
AZ ts
{$ t{$s h{{$? Bt sAstIBt j }? B I
h{{$? Bt
}s s
? sJZ$tsR }B R$ 8} 8$R $BRsR NBR stI R jB BR s JZ$ { ? Bt${BR $t t$ $j R I js YZ8st$IsI I RI jsR }$ ? s8$I R YsR s jBR sR{s{$ jBR }sRstIB }B jBR }Z t R {Bj st R k jsR stI R } RsR tI ? st s AZ t R Z B RZ {Bt $tZs{$? Bt t j R}s{$B NsR R s{$Bt R B A$ sj R }B ` 8}jB k jsR PZ Z sR AsR R jZts R {BtR $ Zk t ks jBR } $8 BR }sRBR AsjAZ{ st R t R s I$ {{$? Bt Ns R$ Zs{$? Bt I $t s%$I 9 t Zt {sRB k Zts s% IsI 8 tB t B B RZ}BtI ? st Zts skZIs $t R $8sAj }s s RBj% t s jsR R ${{$Bt R JZ js PZ 9s I js s% IsI $8}Bt s jsR {BtR Z{{$Bt R R R sZtJZ jjB R$ T t$h{s ? s s8A$? t js s}s ${$? Bt I B BR } BAj 8sR w{BtI${$Bt R sI% RsR } R$Bt R I$P t R D WB R I - sK ts JZ st PsR{$tst R } %$R$Bt R Yskst {sZ $%sIB k jB R$ st Ys{$ tIB s jBR R{ $ B R I {$ t{$s h{{$? Bt eR}s{$B}Z BR {$ZIsI R B A$ sj R B ts% R t s{$Btsj R PB 8st ks }s $t st I js 8$tBjB ? s I js {$ t{$s h{{$? Bt {Bt %$RBR I {Bt% $ R t sj$IsI sj tB R 8? sR JZ Zts - s}Bjs{$? Bt I jsR }B t{$sj$IsI R I js {tBjB ? s s{ Zsj ? sR $8s $T ts{$? Bt I B{Yst jsR I R{ $}{$Bt R I RsR stI R {BtR Z{{$Bt R s jsR JZ js 8stB I j YB8A R s` ts 7 s s I jB JZ j tB% j$R s _Y$jj$} *${, Ys IsIB t jjs8s
$ *Z8} !A` { RU
© Los autores, 2001; © Edicions UPC, 2001.
-
* $t Bt s e$tR $t
t$ 8? s ${sR R Z{ Z sR {BtR Z$IsR t sj8 t }B 8$R $BRsR s9sR - s R R s%stT 9sIsR k ks - $t Z$IsR JZ RBt I R{ZA$ sR t j R}s{$B B t B BR }jst sR }B $t ? }$IBR -}jB sIB R YZ8stBR =tBR YZ8stBR JZ 8Z R st RZ RB } Rs RZ $8}B t{$s k RZ P ZR s{$? Bt st $t t$BR {ZkB BA` B B htsj$IsI RBt $t{s}s{ R I sI$%$ts t$ st R$JZ$ s $t Z$ k 8Z{YB 8 tBR {B8} tI NBR ` 8}jBR tZ8 BRBR }BR t R R t $IB I js 8s s%$jjs JZ {s s{ $9s s js AZ ts {$ t{$s h{{$? Bt =tB I jBR 8skB R BA` BR s $h{$sj R `s8? sR $8s $tsIB R j %sR B 8ZtIB st$jjB Zts {BtR Z{{$? Bt stZjs 8 ? sj${s JZ B{Z}s Zts B ? A$ s }jst s $s t B tB s Zt RBj ]Bt RZR { {s I 8$j 8$jjBt R I ,$j? B8 BR I {$ {ZtP t{$s R s t$ 8? s ${s BA s $t t$ $j R I Y {YB j { t B JZ }Bjs $9s js s t{$? Bt I js tB% js ZtIB st$jjB I Ns k W$% t IBtI R ts st jsR s% t Z sR I Zts {Z $BRs -} I${$? Bt 8 9{js I R R k sj$ t? tsR t%$sIs }s s $t% R $ s js ts Z sj 9s k PZt{$? Bt I j s Ps{ B et q$ ? st >d H I FBYt zs j k Zt JZ$}B I sR BtsZ sR I js WV7V t RZ %$s` Ys{$s 7s Z tB I R{ZA Zt 8ZtIB s $h{$sj t PB 8s I Z Is I d!n(( ,8 I I$? s8 B YsA$ sIB }B Zts I$%$t$IsI p s { sIB s I j 8$R8B ]s} Z sIs js ts% IBR I RZR $}Zjst R 8} tI t Zt %$s` }B j $t $B Ys{$s j { t B I js Z Is _ $}jB JZ j R jj %s ? s s %$%$ s% t Z sR R$t {Z t B t Zt - sK tB jZ s IBtI js $8s $ts{$? Bt I RsPB sIs I RZ sZ B R$ ? Zs s RZ sj$R sR { $s Z sR sj R {B8B {st Z BR I R $R }s sR Rsj{Y${YsR %BjsIB sR { t sZ BR B AB8AsR %Bjst R JZ RBt B st$R8BR %$%BR et ]$ s {Bt is8s >i tI 9%BZR b$ Y is8s d nH I V YZ ] ]js , t 8BR Zt s Ps{ B I s8sK tB $tP $B sZtJZ tB 8 tBR $t{B8} tR$Aj 7 s s I Zt {$j$tI B I n( ,8 I js B Zts R} {$ I tB 8 ts% JZ $ Z8} t j 7$R 8s 7Bjs Ns -} I${$? Bt R t%$sIs }s s -}jB s R 8ZtIB I R$8 ? s {$j? tI ${s } R t{$s ? s {? B8B sj s{ {s R sj 7Bj 4B { 8B8 t ? st s8 t js %$Is s $h{$sj t RZ $t $B _ B j s Ps{ B R RPZ8s ? s jj %? stIBR {Bt B-$8s t s gB RB { ? s8BR D ? j RZ 8$R $B wYsR s js } ? p s{$sR sj $t ? R RZR{$ sIB t jBR j { B R k s jsR }BR$A$j$IsI R t %$R sR }B jBR htsj R sA$ BR I I${YsR tB% jsR BIsR jjsR Yst IsIB }$ s RZR R} { $%sR {Bt $tZs{$Bt R VR? W$% t Ys R{ $ B NBR $t t$ BR I j ZtIB st$jjB >i$t bB jI et $t R d H k i$t bB jI qY Bt >d EH 8$ t sR JZ zs j k k ]js , Yst R Z$IB `Z stIB {Bt j 8$R $B JZ t%Z j% s RZR $t t$BR ej } $8 B t Ns Y {Y$9 s >G$9s I d M(H k * 8Bt >d M;H ej R ZtIB t {BjsAB s{$? Bt {Bt p t k N t is8s yy >d M H ej `s I? t I is8s >qY ps I t BP is8s d dH k is8s % jsIs >is8s i % sj I d ;H FZt B s R sR BA sR PZtIs8 t sj R RBA j Bt t 8s JZ tBR B{Z}s {sA sK tsI$ js tB% js e? Bt >eBt d MxH wJZ $ t RZ {Bt $tZs{$? e t$IsI >e t$ k d MMHD I p s IBtI R I R{ $A Zt 8ZtIBTZt$% RB sj ts $%B I R{ZA$ B t Zt sR B$I YZ {B JZ R s{ {s s js q$ s eR sR 8s tsR BA sR I $t t$ ? s R}s{$sj RBt RZ} sIsR t s8sK tB }B jsR RP sR I *kRBt JZ R I R{ $A t t tB% jsR {B8B ! A$ R%$jj >d xH I BA 7Ysb 3s Y R 7 s >d xH I 3 I $, _BYj k Fs{, G$jj$s8RBt B NsR ts% R I j $ 8}B I 7 }Y t s- et js tB% js ej YB8A t j jsA $t B >qY st $t Y s9 d E H I iBA 7$j% A js s{{$? Bt stR{Z t Zt st $ ZB }jst s N 8tBR
s`B R s $8s $ts $%s $I s }Z I t jBAs R js { t{$s }R ZIB{$ t ? h{s RBA j B $ t -T s R I js jZts 8s {$sts 3BABRU RZ - sK ts PB 8s $ Zjs w ? }${s I Zt BA` B I s8sK tB s I RZ B ? A$ s sj }jst s YsA ? st {Bt $AZ$IB s PB `s RZ RZ}Z R B 8 I$B I ZtBR 1( ,8D k js { {st? B $ t s $h{$sj
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
-@
sAstIBtsIB }B Zts - sK ts k I R{BtB{$Is s9s I Rs}s {$Is Ys{ 8$j R$ jBR 7? BjB JZ Ist I jjs R BR PBR$j$9sIBR I YZ RBR P s 8 t BR I 8? sJZ$tsR k Zt t$ 8? s ${B sZ BRZh{$ t }j B I s8}sR 8B sj R I$sA? Bj${B k R$t R t $IB jsA $t B ]ZstIB Zts {tBjB ? s s` ts s js YZ8sts JZ R R$ % I 8s $sj R I R{BtB{$IBR I } B}$ IsI R RB } tI t R R ? s I ? sR I R sR 8s tsR R Z{ Z sR sj$ t? tsR }B{B }Z I I {$ R 8? sR JZ I R s JZ }B jB 8 tBR jsR j k R P? R${sR ? R sR R? Zt$% Rsj R R R$ st % $h{stIB 7$ t js{$? Bt {Bt R 8s tB Y 8BR {$ sIB t$t Zts BA s P? j8${s R }B JZ t R 8 I$B -$R t B tB sj 8$R8B Zt %s{? B } ? s{ ${s8 t sARBjZ B +Z$9? sR j Z ?t${B ` 8}jB {BtR Z$IB R s js 8sJZ$ts $s sj$ t? ts JZ s}s { t j hj8 _jst s } BY$A$IB NBR } BAj 8sR JZ }jst st s tZ R s $8s $ts{$? Bt js {Bt{ }{$? Bt I s8sK tBR s Ps{ BR }s { t R s8A$? t js } $t{$}sj I$h{Zj sI }s s jj %s jBR s js }st sjjs }B }s I jBR JZ$}BR {$t 8s B ? sh{BR I P { BR R} T {$sj R ? s-$8 {ZstIB {B8B t jsR tB% jsR {$ sIsR j ` { t sj I js Y$R B $s tB RBt st B jBR } RBts` R JZ s}s { t {B8B j } B}$B BA` B t R? w j ` 8}jB I ]$ s {Bt is8s R A$ t {js BD yt{jZRB }s s js 8s $s I j {$t R BR I R8 RZ sIBR $t t$BR RZj st RB Zts I R8 RZ s
!A` B wh{{$? BtD
qs8sK tB d(@ ,8 d( ,8 nE!((( ,8 d!n(( ,8 n( ,8 dx ,8 n ,8
eRP s I *kRBt ZtIB st$jjB VR{ tRB R}s{$sj q$ ? st is8s _Z t I p$A sj s BtZ AR
!A` B w sjD p st Z sjjs {Y$ts _Z t V,sRY$ s$,kB qB R I _ BtsR qB e$& j q$ st${ _$ ? s8$I I B}R ]BY RB%$? ${B _ B ? Bt eR s{$? Bt B A$ sj $ ${ B8B B R ${ B{Y$}R
qs8sK tB
E!n(( ,8 n, ,8 ;xd, 8 n(( 8 1E 8 d;E 8 E( 8 1x 8 n(( d( - 8 d( - 8
7ZA8s $tB
_ B ZR
d( - 8
qsAjs d n ]B8}s s{$? Bt t jBR s8sK tBR I jsR {BtR Z{{$Bt R YZ8stsR B sj$ t? tsR I js h{{$? Bt {$ sIsR t j - B k jBR jB BR YZ8stBR sj R
_$RsIsR sj$ t? tsR t js B $jjs R Ns 8skB ? s I jsR % { R js {tBjB ? s - s R { sIs }B jBR PsA ${st R I RZ K tBR tB I R s{s } {$Rs8 t }B RZR I$8 tR$Bt R R$tB }B RZ }B t{$sj 7$t 8As B ? R s R$ Z RZj stIB t$ 8? s ${s $t{B8} tR$Aj 7$ 8Z{YBR I jBR s}s s BR k 8? sJZ$tsR {Bt jBR JZ Bt j? PBtBR 8? B%$j R B I tsIB R D RZj s ? st s $jZ $BR {Bt%$%$8BR YBk t I? s w j %$R$? I$sA? Bj${BR }s s tZ R BR st }sRsIBR ws % { R s8A$? t }s s tBRB BR 8$R8BRD 5{? B8B tB %s s R - sK ts 8$R $BRs $8} t sAj Zts {tBjB ? s I Rs BjjsIs }B R R 8? sR s%st9sIBR {Bt B sR htsj$IsI R t B BR 8ZtIBR2 O R$ t{$8s t$ st R$JZ$ s t 8BR { {s s RZR { sIB R
© Los autores, 2001; © Edicions UPC, 2001.
-
* $t Bt s e$tR $t
3$ d d; V $jZ $BR I ZRB {B $I$stB {ZkB PZt{$Bts8$ t B s IZ sR } tsR {B8} tI 8BR
}s s JZ tBR skZI t s Z $j$9s js }Z R ks tBR I$ ? st et j js B - tI$IB s tB% js _? {t${ - s R >_$,t$, ts BAB{Y$t d 1H I V {sI$ k B $R 7 Z s R,$ R { s Zts 8$R $BRs
9Bts t ]stsI? s IBtI }Z I t Ysjjs R s Ps{ BR t$ 8? s ${BR sAstIBtsIBR {B8B R$ PZ R t I R} I${$BR I Zt }${Tt${ }B Zts s9s sj$ t? ts et js } j? {Zjs 7 sj, >d H AsRsIs t R s tB% js t jZ s I jBR tR R sj$ t? tsR R ? s js <sA$ s{$? Bt Zt jZ s IBtI jBR 8? sR {? BtI$ BR I R BR }Z I t sj$9s R _s s sj{st9s js ZtB I A sI t s R t Zt jZ s } BY$A$IBU js Bts PB B shsIs t {BjB t {Bt sR {Bt js I RBjsIs 9Bts $tIZR $sj {$ {ZtIst hj8sIs s I Zts =t$? Bt 7B%$? ${s t t Ajst{B k t B wk IBtI sj ZtBR Yst JZ $IB % Zts sj B ? I R{B8}BR${$? BtD =tBR s B 8 t sIBR k 8? R BR $tI$%$IZBR I tB8$tsIBR R sj, JZ 8sj%$% t s AsR I % tI jBR BA` BR t{Bt sIBR t js 8$R8s R$ % t I Z? sR et js tB% js _? B ${B >ps bsk d H I 3 I $, _BYj js YZ8st$IsI I R{ZA Zts R} {$ I AsR R}s{$sj {BtR Z$Is t Zt sR B$I B t? Z{j B {B8 s $B }B Zts 8$R $BRs R} {$ - s R I Rs}s {$Is 8 I$B 8$jj? Bt I sK tBR s ? sRU jBR Y {Y 7ZR ts% R sZ B8? s ${sR $t s{ sR } 8$ t s sJZ jjBR JZ I {$I t } BAs RZ }s $ Ys{$s 8ZtIBR I R{BtB{$IBR Ns PB Zts B js 8Z j R s Zs Ist _? B ${B R j tB8A JZ {$A R s }Z s sA$ s s js $t8 tR$IsI I jBR }s s? RBR $th tBR JZ R{BtI j {BR8BR =ts {B8}sK t? s js ]B }B s{$? Bt R t{s s I -}jB s jsR ts% R R}s{$sj R sAstIBtsIsR }B jBR Y {Y "O I {B8 {$s I Rs Bjjs B Z $j$9s {B8B {Bt% t s jBR s Ps{ BR 8 {st{? sR 8s $sR } $8sR Z B sR {BRsR I %sjB I R{ZA$ sR }B 8 I$B I R sR ts% R" Ns R $ R {B8}j s }B j 8B8 t B {Bt R t sR 8? sR JZ } BPZtI$9st t jBR 8$R $BR JZ BI st s R s s9s - s R wq sR j $t{$ B YB $9Bt > kBtI Y jZ e% t <B $9Bt d M(H ej t{Z t B >< {Y i tI 9%BZR d M;H k NBR stsj R I jBR < {Y R >qY VttsjR BP Y < {Y d M HD et j js B Ns YB 8$ s $ st >qY p$st Vt d EdH I <Bbs I 3sR R I R{ $A Zts R} {$
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
En
I YB 8$ sR I 8 I$B 8 B I s8sK tB {ZkB ? B s- sjA s Zt { } ? s{ZjB {Bt I$% RBR Z tT R$j$BR $tR Z8 t BR Pst ? sR ${BR JZ }s { t {s { I R t $IB }s s jBR RB } tI$IBR YZ8stBR JZ jsR R ZI$st Ns ts Z sj 9s $t% BR? 8$j I R sR { $s Z sR jj %s s jBR {$ t ? h{BR s B{Zj s RZ 8 s -$R t{$sU gtsI$ j R Is ? s j 8 tB { ? I$ B eRs $t{s}s{$IsI 8st$h R s }s s RsA j BA` B k htsj$IsI I jBR s $jZ $BR sj$ t? tsR JZ s}s { t t R sR BA sR 4 `s s8A$? t jsR I$h{Zj sI R JZ $ t j R YZ8stB }s s {B8} tI js {tBjB ? s JZ jB BI s =tBR tR R JZ PB 8st }s $tI$RBjZAj I j t B tB t JZ %$%$8BR k JZ {B8B R$ I s}s s BR - s R R R s s s Z $j$9s8BR } B s 8 tZIB tB {B8} tI 8BR@
q {tBjB ? s k Z B}? s Os I RI js %BjZ{$? Bt $tIZR $sj js s{ $ ZI st js {tBjB ? s Ys R$IB s8A$%sj t V js { t{$s B} $8$R s I JZ j } B RB {tBj? B ${B jj %s 8}s `sIB j } B RB 8B sj I js YZ8st$IsI R 8$R8s R$tB t RZ ZRBD {Bt s}Bt Zts s{ $ ZI } R$8$R s JZ % t js {tBjB ? s w sj % 9 tB t R? Zt 8B $%B I } B{Z}s{$? Bt Ns }Bj? 8${s s{ Zsj RBA js $t t$ ? s t? ${s R Zt {js B ` 8}jB I jjB Ns {$ t{$s h{{$? Bt tB Ys R$IB s` ts s R s I${B B8? s k st {s8} Bt R I j B} $8$R8B k @@ t ZR$sR sR I j } B RB {tBj? B ${B {B8B FZj R z t wdM1MTd (xD yRss{ VR$8B% B V YZ ] ]js , }Z I t {Bt s}Bt R B BR sZ B R {B8B VjIBZR <Z-j k 7 st$Rjsb N 8 B j < A p G jjR }BR $B s js y pZ s ZtI$sj JZ sIB} st }BR Z sR 8? sR { ? ${sR WB t %stB js {$ t{$s h{{$? Bt {B8B RBR $ t _ W${YBjjR R j 8 I$B ts Z sj st B I jsR Pst sR? sR st $ {tBj? B ${sR {B8B I jsR - s}Bjs{$Bt R 8? sR B 8 tBR R $sR I jsR }BR$A$j$IsI R {tBj? B ${sR Vt { I t R tB sAj R t js I R{ $}{$? Bt I 8s s%$jjBRsR {tBjB ? sR jBR t 8BR t Ns tZ %s V j? st $Is >dE1 H I j hj? BRBPB k {$ t ? h{B 3 st{$R s{Bt wdx1dTdE1ED IBtI R - s}Bjs js {T
tBjB ? s {Bt 8}B ? st s }s s } BAs jBR j? 8$ R I RZ } s{ ${sA$j$IsI B R k As {BR RZ8 $T Aj R 8? sJZ$tsR JZ $8$ st j %Z jB I jBR }? s`s BR k } 8$ t %Bjs s $jZ $BR JZ } BIZ{ t jZ9 skZIsR }s s js %$R s k js sZI${$? Bt 8 I$BR }s s js {BtIZ{{$? Bt I RBt$IBR s I$R st{$s { RBt sj ZtBR I jBR {s{Y$%s{Y R JZ Zts 8 t s{$Btsj k sA$ s I j R$ jB zyy }BI? s $8s $ts @
i 8$ $8BR sj j { B JZ I R Ys{ R Zts $I s I js {tBjB ? s JZ tBR BI s sj j$A B ]? B8B PZt{$Btst jsR {BRsR >d dH I yst 7 bs t j JZ R I R{ $A I Zts PB 8s s8 ts k sR JZ$Aj j PZt{$Bts8$ t B I 8Zj $ ZI I 8? sJZ$tsR s}s s BR k BA` BR I ZRB YsA$ ZsjU I RI Zts { 8sjj s YsR s j {jsIB I Zt B I tsIB @@ z t sIB} s ? s Ys{$s j htsj I RZ %$Is Zts }BR Z s 8? sR { ? ${s et jsR BA sR I RZ Z ?j $8s s}s jj s s }Bt t {Z R $? Bt tB js {$ t{$s k js ? {t${s t R? 8$R8sR R$tB RZ 8sj ZRB NB JZ sj ? Zt { ? ${B I RZ BA s Ys % t$IB s I tB8$ts js } % R$? Bt I js {$ t{$s et ZtB I RZR js BR }? BR Z8BR ej Z ?j $8B VI? st >N: t j VIs8 d d H j } R$8$R8B I z t sj{st9s {B sR $tRBR} {YsIsRU sR Zts {s ? sR BP JZ s sRs BIs js q$ s Zt Z}B I } RBtsR s AB IB I Zt ts%? B IB sIB {Bt BIBR jBR sI jst BR {$ t ? h{BR k {B8BI$IsI R I R 8As {s t ZtB I jBR }B{BR } Is9BR I $ s h 8 tB t Zjj$IBR }B j 8s eR Z}B I YB8A R tB R? BjB tB jB s {BtJZ$R s {$ t ? h{s8 t j tZ %B {Bt $t t R$tB JZ }B j {Bt s $B R RZ8 t js As As $ k js YZ8st$IsI I A 8} 9s I tZ %B ]Z? st j `BR JZ Is R s Z8 t B I j I B s tB% js RZks Ns $Rjs 8$R $BRs >N:| yj kR ? ZR dM xH IBtI ZtBR }B{BR YB8A R R$t 8? sR }BR R$Bt R JZ RZ {Zj Z s {$ t ? h{s jB st IB8$ts Zts $Rjs
© Los autores, 2001; © Edicions UPC, 2001.
E;
* $t Bt s e$tR $t
_ B t R s Z B}? s {$ t ? h{s R 8Z{YB 8? sR $t Rst js I R{ $}{$? Bt JZ Ys{ s{Bt I Zts RB{$ IsI $Is }B Zts {B8Zt$IsI I RsA$BR Ns ]sRs I 7sjB8? Bt R Z{ Z sIs t PZt{$? Bt I jsR {$ t{$sR k j } B RB Ns {$ t{$s PZtIs8 t sj8 t AZ ts } B{Z s jBR 8 I$BR }s s Rs $RPs{ jsR t { R$IsI R YZ8stsR O jjB R RZh{$ t }s s JZ js RB{$ IsI R s P j$9 Vj t$% j I %$R$Bts $BR {B8B z t B G jjR {sA {$ s s8A$? t sj R{ $ B k I$ B <Z B p tRAs{,@ eR t ZR$sR s I jsR tZ %sR {tBjB ? sR $t{$}$ t R s } $t{$}$BR I R$ jB {B8B js sI$B k js j { ${$IsI R ? s ZtB I jBR } $8 BR t $t{jZ$ t jsR %$R sR ? {t${sR JZ ? j 8$R8B I$ sAs {B8B BI t ej { ${R - s}Bjs{$Bt R I js {tBjB ? s I js ? }B{s ej js B isj}Y d1;] ;dL >d ddH }ZAj${sIB t sJZ? jjs R Zt 8Z R s $B I js 8s s%$jjBRs {tBjB ? s I j R$ jB zyy 8}s t sIB {Bt js tB% js I s{Bt et jBR AsjAZ{ BR I j $t{$}$ t {$t R Ysjjst ks 8Z R sR s 8 tZIB t }jst I AZ js I jsR {BtR {Z t{$sR s jsR JZ j } B RB {$ t ? h{B k {tBj? B ${B }Z I {BtIZ{$ ]Ys {Z $ ? {st$JZ >dM EH I jBR Y 8stBR NZ8$r R j } $8 hj8 t }jsR8s t {js% I YZ8B }B{s s{ Zsj I R s $I s ]Bt Zts IZ s{$? Bt I Zt 8$tZ B wsj B $t{Bt{ A$Aj t tZ R s ? js B8 s` RD 8Z R s j PZt{$Bts8$ t B I Zt {Z $BRB s}s s B {s}s9 I {Bt% $ 8 I$st Zt R$8}j $t Z} B s Zt { IB %$%B t Zts sZ ? t ${s }s sIs {Ys {Z sU Zts RZ{ R$? Bt I `s8Bt R k Rsj{Y${YsR _B{B I R}Z? R qY 7sZRs s{Y$t >dM H s}B s ? s Zts %s $st I R s $I s sj RZAR $ Z$ sj { IB }B ZtBR } BR {sjj ` BR ej sAst${B st$8sj RZR{ } $Aj I R stRPB 8sIB t } BIZ{ BR I {Ys {Z ? s 8 I$st Zts tB 8 tBR } BI$ $BRs 8? sJZ$ts R % ? s - tI$IB s } BR s BR k Zt }s B t j hj8 s,$t 7sZRs R >dM H Ns {B8}sK t? s s 3Zt {$t 8s B ? sh{s { sIs }B j } Bj? h{B $t% t B qYB8sR V eI$RBt wdM; Td ndD BIs ? $t s Z {Y 7YB} >d (dH I R$8$js s Z8 t B k t *B 3s{ B k >d (;H B ts ? s sj 8$R8B 8s sZtJZ sYB s js 8? sJZ$ts {Bt j BR t BRB ? ZjB I "q stRPB 8sIB I } BR" w*B Zs j } B{ RB s js $t% RsU BA $ t {st R s }s $ I ZtsR {Zst sR Rsj{Y${YsR q stRPB 8 D P { ? et js s{ Zsj$IsI k } R s JZ js $t % t{$? Bt I js 8stB I j YB8A t js 8skB ? s I jBR } B{ RBR $tIZR $sj R R {sIs % 9 8 tB s? Zt tB R Ys sj{st9sIB R sIB I sZ B8s $9s{$? Bt w$t{jZRB t js 8s st9s I j { IBD JZ I RI Zts } R} { $%s B R{BTYZ8B ? R ${s } {Bt$9st R BR hj8 R }$Bt BR et jjBR t 8BR Zt P t j `stB I jBR I$R}BR$ $%BR JZ I$R} tRst I Zts PB 8s B sj8 t sZ B8? s ${s k s %BjZt sI {ZsjJZ$ $}B I 8st`s {B{$tsIB B tB s jBR 8$ 8A BR I jsR $}Zjs{$Bt R I jsR ts% R R}s{$sj R I js h{{$? Bt {B8B t js }B}Zjs R $ 7 s q , ej BAB iBAAk JZ s}s { t js } j? {Zjs _jst s } BY$A$IB I$R K tsIB {Bt js {tBjB ? s - s R I js s9s , jj R j 8BI jB I 8? sJZ$tsT BAB {s}s9 I Rs $RPs{ jsR t { R$IsI R 8? sR j 8 t sj R I RZR s8BR et }s ${Zjs I PsA ${s { t ts R I j$ BR I bY$R,k k Bt jsIsR I }jB8B gR$t t { R$IsI I 8s $s } $8s ]sA } tRs JZ j R$8}? s ${B iBAAk {Bt%$ t ? s t 8Bj? {ZjsR I {ZsjJZ$ RZAR st{$s VZtJZ tB R 8Z R s t j hj8 }Z I I IZ{$ R JZ js $t t {st $IsI I t ? s JZ R t { R$ s }s s Zts B} s{$? Bt I R $}B js BA $ t s AsR I " t{YZPs R " ? j 8$R8B s jBR s{ B R 8BtZ{j s R , jj
<Z B p tRAs{, R {BtR$I sIB }B 8Z{YBR {B8B j }sI js {$ t{$s h{{$? Bt 8BI ts * Y {YB R JZ$ t Is ? s tB8A sj ? t B k Zt % Y? {ZjB }s s RZ -} R$? Bt NBR 7{$ t{ 3${ $Bt V{Y$ % 8 t ? R{s " {$t 8s B ? Vbs IR } 8$BR JZ$%sj t R s jBR "! sh{BR {$A t j tB8A I "<Z B" t RZ YBtB @
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
-N
*$P? {$j R s{ } s s8A$? t jsR } B}$ IsI R I j 8 sj , jj JZ I R{ $A j * B A$ZR ej t$ 8? s ${B hj? BjB B JZ jj %s sK tBR I RZ %$Is {BtRs sIB sj R ZI$B I js 8$R $BRs {tBjB ? s j sIs }B R s - $t s s9s sj$ t? ts R K tsjs JZ jsR 8Bj? {ZjsR JZ jB {BtR $ Zk t RBt %s $sR % { R 8? sR I tRsR JZ jsR I j s{ B R B I$ts $B sZtJZ tB RBt 8Bj? {ZjsR I$P t R 5]? B8B }Z I {s8A$s R I PB 8s RZAR st{$sj j sIB I 8}sJZ sIB I 8Bj? {ZjsR R$8$js R I Zt 8$R8B 8s $sj2 VK tsI$ tIB B - sk tIB s ? B8BR } B t Bt{ R tI 8BR B B $}B I 8Bj? {ZjsR ]js B JZ s ? stIBR I {tBjB ? s - s R {ZsjJZ$ {BRs R $8s $tsAj ]ZstIB j {B8stIst VIs8R JZ I$ $ js -} I${$? Bt R sj }jst s Vj s$ yz I$R}s s RZ }$R Bjs I R$t sIB s {Bt s js }Zj$Is RZ} h{$ 8 ? sj${s I Zts }s I I j jsAB s B $B , jj j * B A$ZR -}j${s JZ j 8 sj , jj "sARB A t ? s {B8B Zts R}Bt`s" k tB R {sj$ t s _ B}$ IsI s8A$? t I$P? {$j I sRZ8$ 7$ j 8s $sj tB -} $8 t s t$t ? Zt $}B I P { B wt$ R {sj$ t s t$ R PZtI D 5I? BtI Ys $IB s }s s t Bt{ R js t ? s2 ]B8B R K tsjs V YZ ] ]js , jB 8? sR } BAsAj R JZ {ZsjJZ$ s $jZ $B I j PZ Z B B {T tBj? B ${s8 t s%st9sIB R s {BtR$I sIB {B8B 8? s ${B k s RZR }BR IB R R j R B B Z j {s ? s{ I$%$tB et js tB% js +Z? I$P? {$j R R *$BR >q ZItB Ak : AB B8 d E;H I V {sI$ k B $R 7 Z s R,$ wsIs} sIs sj {$t {Bt j tB8A I ej }BI I Zt *$BR ><s I B s pBI d (HD R I R{ $A Zts RB{$ IsI I $}B P ZIsj t Zt }jst s IB8$tsIB }B Zt IZ{$IB Z}B I YZ8stBR {ZkB ZRB I js {tBjB ? s Ys{ JZ R st %$R BR {B8B I$BR R Ns tB% js _s%sts >_s%st d EMH I $ Y iBA R R Zts Z{ Bt? sU j {s8A$B I Zt Y {YB Y$R ? B ${B wjs V 8sIs yt% t{$Aj I 3 j$} yy RZj s t P { B "$t% t{$Aj " k p st sK ts R {BtJZ$R sIsD }BR$T A$j$ s js Y 8Bt? s {Zj Z sj I js y j R$s {s ? Bj${s k js ytJZ$R${$? Bt t eZ B}s IZ st R$ jBR Ns {$ t{$s R ? s } BR{ $ s k j } B RB R Ys I t$IB et jBR sK tBR ( jsR jB{B8B B sR s %s}B s? Zt {B t jBR {s8$tBR k jsR {B8Zt${s{$Bt R R sj$9st %$RZsj8 t }B 8 I$B I Zts I I R 8? sPB BR YZ8stBR VZtJZ RB}jst jBR %$ t BR I Zts %BjZ{$? Bt {$ t ? h{s s8}s sIs t ZtBR ZI$8 t s $BR {BtB{$8$ t BR I JZ? 8${s k I j { ${$IsI ]B8B {Bt s}BR${$? Bt sj }s} j I Zts y j R$s JZ $8}$I j s%st{ {$ t ? h{B }s s } } Zs R t j }BI js tB% js ]? st ${B }B N $ABb$ 9 >V ]st ${j PB N $ABb$ 9 d E(H I Gsj $jj I h tI jsR % t s`sR JZ }s s js YZ8st$IsI $ t j $t8B%$j$R8B k j {BtR %sIZ $R8B I js 8$R8s sYB s t Zt 8ZtIB I %sR sIB }B js yyy pZ s ZtI$sj $j B{YB{$ t BR sK tBR I R}Z? R I j YBjB{sZR B js }? I$Is I $t4Z t{$s I js B I t k j RZ $8$ t B I js {$ t{$s {Bt RZR }B t{$sj$IsI R k $ R BR }s { t sAB{s I tZ %B s js YZ8st$IsI s Zt $t8$t t YBjB{sZR B NBR 8$ 8A BR I js B T I t } }s st RZ YZ$Is t Zts ts% R}s{$sj {Bt js R} st9s I %Bj% k s{B s j $ 8}B I BR{Z st $R8B k As As $ JZ R s% {$ts Bt {$t 8s B ? sh{s s{sAs I et ej {s B >qY _BR 8st d MxH I *s%$I $t w{Zks % R$? R ts R {$ t 8 t As`B j ? ZjB tRs` B I j PZ Z B >qY _BR 8st d HD tB R js y j R$s R$tB Zt $tI$%$IZB j {s sj$9sIB I j RZ $8$ t B 8B sj RB{$sj k {tBj? B ${B I Zts YZ8st$IsI I$ 98sIs I RBjsIs k I RB st$9sIs sR Zts {Bt4s s{$? Bt tZ{j s Ns jjs8s I js R} st9s js t{$ tI I PB 8s $t%BjZt s $s Zt %s sAZtIB pB IBt s 9 JZ Zt AZ t I? s t{Z t s Zt Zt$PB 8 I {s B k R jB }Bt }s s } B R I j P ? B Ns $I s j stY jB I js -$R t{$s I Zt {$ s B st$9s{$? Bt { t sj 8}$ 9s s - tI R k pB IBt sRZ8$ ? s RZ }s} j I R? 8ABjB t j JZ RZR {Bt ? t R Yst I }BR$ sIB BIBR RZR RZ K tBR k R} st9sR et js } j? {Zjs Ns %$Is PZ Z s >qY$t R B ]B8 d nEH AsRsIs t js tB% js I < A p G jjR qY 7Ys} BP
© Los autores, 2001; © Edicions UPC, 2001.
--
* $t Bt s e$tR $t YB8A R I j s$
qY$t R B ]B8
>d nnH k {Bt Z$? Bt I j 8$R8B R Zt Z}B I {$ t ? h{BR jBR
JZ$ t R Ys } B}Z R B } R %s js {$%$j$9s{$? Bt et Zt 8ZtIB IBtI s} tsR JZ Ist % R $ $BR I js {$ t{$s k I js ? {t${s st $B R s Zts yy pZ s ZtI$sj JZ R } BjBt s }B R}s{$B I n( sK tBR k st Zts YZ8st$IsI sAB{sIs s js As As $ js s}s ${$? Bt I R BR YB8A R s AB IB I ZtB I jBR Z ? j $8BR s B}jstBR JZ JZ Ist R$ % }s s sA $ Zts tZ %s }Z s s js R} st9s Ns } j? {Zjs } 8$ s G jjR 8BR s RZR $tJZ$ ZI R st Zt PZ Z B 8? sR A$ t BR{Z B $t %$ sAj R$ jBR YZ8stBR tB R }jst st B B 8 `B
ytI } tI$ t 8 t I js %$R$? Bt B} $8$R s B } R$8$R s sIB} sIs jB JZ }s { PZ s I BIs IZIs R JZ jsR 8? sJZ$tsR js {tBjB ? s }B R? RBjsR tB } B}B {$Btst js P j${$IsI et js } j? {Zjs
Vj Bj
>d 1(H j R}? $ Z I js R jjs Vj Bj t s s Zt 8$t B Zts t$ 8? s ${s 8? sJZ$ts sj B
sR? {B8B js j? s8}s s 8s s%$jjBRs I VjsI$tB JZ j } B}B {$Bts BIs RZ I $JZ 9sR sZtJZ tB js P j${$IsI et B BR {sRBR I$R}Bt I BIs js {tBjB ? s $8s $tsAj }Z I RZj s Vt tB% jsR {B8B
$t{jZRB {Bt s} BIZ{ t
e bYBt
>dM 1H I 7s8Z j
1(((TdMM k
sZ B8s $9s{$? Bt R j } jZI$B I Zt R$R 8s I %$Is 8 {? st${B %BjZ{$BtsIB >dMMMH I eIZs I
NBB,$t s{,bs I
Z j IBtI js
jjs8k JZ Is Zts %$R$? Bt Z ? B}${s I Zt 8ZtIB RB{$sj$9sIB IBtI
jsR 8? sJZ$tsR Yst s{sAsIB {Bt BIBR jBR 8sj R k jsR Z B}? sR b jjR$stsR
t N$, pBIR
V BI t = B}$s
>d (xH
>d 1nH JZ I R{ $A t RB{$ IsI R {tBj? B ${s8 t s%st9sIsR BA tsIsR {Bt
} $t{$}$BR RB{$sj$R sR }Z I t {Bt s}Bt R B sR {B8B
qY s{Y$t 7 B}R
>d ( H I e
3B R JZ }jst s JZ Zts RB{$ IsI t js JZ tsI$ $ t JZ sAs`s R st $t Bj sAj {B8B Zts RB{$ IsI I R{js%BRU jsR %$IsR I jBR YZ8stBR R B tst %s{? sR k R$t BA` $%BR
Vj B }s {$IB s jB JZ RZ{ I t js tB% js G$jj$s8RBtU jBR
YZ8stB$I R
NBR YZ8stB$I R
>qY <Z8stB$IR d ; H I Fs{,
RBt ZtBR } JZ K tBR BAB R I s}s $ t{$s YZ8sts st h{$ t R JZ
}s sI? B`${s8 t $8}$I t s jBR YB8A R {ZsjJZ$ s{{$? Bt j$A s sj ZtBR YZ8stBR JZ jBR % ? st {B8B Zts s8 ts9s sj et
_jsk _$stB
NB {Zsj {js B R ? s tB ZR s >d x1H I Z
zBtt Z js } B}$BR YZ8stBR I R t{sI tst Zts %BjZ{$? Bt {Bt s js sZ B8s $9s{$? Bt
Z{YsR I jsR Z B}? sR t s $%sR B
I$R B}? sR RB8s
8? sR {BtB{$IsR R AsRst t js IB8$ts{$? Bt I j R
YZ8stB }B BA$ tBR B sj$ s $BR JZ Z $j$9st js {tBjB ? s }s s I${YB ht et >
=t 8ZtIB P j$9
s% W b GB jI d n1H I VjIBZR <Z-j k R js 8st$}Zjs{$? Bt t? ${s `Zt B sj {BtRZ8B JZ$ t }BR$A$j$ s j {Bt Bj RB{$sj t Zt 8ZtIB
I Zts I B s I ZRB t sj$9sIB j IBtI < t k 3B I R I $h{sIB
et js {BtB{$Is tB% js
d M;
>W$t t e$ Y kT3BZ d ; H
Bt$8B I e ${ V YZ I p B ! b jj w}R ZI?
js$ D j %$ $jst BR B I j
p st < 8stB
{Bt RZ B8t$} R t{$s t jsR j %$R$Bt R 8Z sj R I {sIs %$%$ tIs k RZR {BtR$ tsR ` { Zt {Bt Bj sARBjZ B RBA js }BAjs{$? Bt w5R s % j { B s AZR{s }s sj j$R8BR {Bt tZ R B 8ZtIB s{ Zsj2D ]Bt Zts R ? ${s R$8$js s js I R s tB% js k sj hj8 YB8? Bt$8B AsRsIB t js 8$R8s js } j? {Zjs
s9$j
>d MxH 8Z R s s8A$? t Zts {jsZR BP? BA${s k ,sP,$sts8 t AZ B{ s $9sIs
s ${BR }B IBtI {$ {Zjst RB{$ IsI IBtI R 8 9{jst s $jZ $BR I js s %${ B $sts w ZABR }t Z8? jBR $ttZ8 sAj R $8} RBRD {Bt B BR I Zts ? }B{s PZ Z s w{B8$Is t PB 8s I }sR sD } B}$B FZj R z t t RZ tB% js
NBR x(( 8$jjBt R I js Z8
ej
>N R {$tJ { t R 8$jj$BtR I js
A? Z8 dM H js s js Y$R B $s I IBR } RBts` R st s ? Bt${BR I Zt {js B R$8ABj$R8BU j * 7s sR$t P st{? R k < 7{YZj 9 sj 8? st ]sIs ZtB I jjBR R Y I B I Zts {Zst $BRs $ t sR
PB Zts {Bt js JZ Ys I {BtR Z$ Zts {$ZIsI $I sj t $ B $B tB s8 ${stB
7s sR$t {BtR Zk Zts {$ZIsI }s{? h{s k Z ? B}${s 7{YZj 9 I$h{s Zts {$ZIsITP? sA ${sTPB sj 9s
© Los autores, 2001; © Edicions UPC, 2001.
d $t Bt YB8A R 8 t Zst R k Zt$% RBR t Zts B s I s Zs
-
I I${sIs s js } BIZ{{$? Bt s 8s8 t ? R ${s JZ $t t s ? s IB8$ts s RZ sI% Rs $B i 4 `B I js $%sj$IsI t Vj 8st$s k 3 st{$s k } jZI$B I js h Z s I j I${ sIB sj 8? st I j R$ Z$ t R$ jB R js } $8 s tB% js IBtI z t 8BR s ? s s jsR {js sR JZ j }BI ? B ? {t${B }Z I t s {B Z}{$? Bt k JZ j {BtB{$8$ t B {$ t ? h{B Z $j$9sIB }B YB8A R } % RBR {BtIZ{ sj 8sj z$R$Bt R st $Z ? B}${sR JZ sj st I j } j$ B I BIB } B RB {tBj? B ${B JZ tB %sks s{B8}sK tsIB I Zt } B RB RB{$sj k 8B sj et {ZsjJZ$ {sRB R s s I $I sR JZ skZIst s 4 -$Bts t B tB sj 8ZtIB t JZ %$%$8BR s AsR I 8BR s js js $%$IsI I jBR %sjB R RB{$sj R B }Bj? ${BR k JZ 8 { t Zt st? sj$R$R t } BPZtI$IsI JZ tBR jj %s ? s 8? sR sjj? s I jsR 8BI R sR } tR$Bt R I R - B ]Bt t ? 8BtBR }s s htsj$9s k s 8BIB I RZ8 t {Bt js R$ Z$ t P sR I V YZ ] ]js , U "qBIB sJZ jjB JZ R ? B ${s8 t }BR$Aj jj s ? s s {BtR Z$ R t js } ? s{ ${s $tI } tI$ t T 8 t I jsR I$h{Zj sI R 8s $sj R JZ jjB RZ}Bt s R$ j I R B I jB s jB R RZh{$ t 8 t PZ " O } }s ? 8BtBR }s s R Z$ s jB js B I jBR } ? B-$8BR {s}? ZjBR j I Rhj I 8? sJZ$tsR I$R}BR$ $%BR k {tBjB ? sR RZ $IsR I js $8s $ts{$? Bt I jBR sZ B R I {$ t{$s h{{$? Bt
© Los autores, 2001; © Edicions UPC, 2001.
1 =ts BI$R s t j R}s{$BU I j et } $R sj <sj{? Bt $j ts $B
-
1
=ts BI$R s t j R}s{$BU I j et } $R sj <sj{? Bt $j ts $B
7BA $t 8$tsAj R { Z{ BR t j B{? stB I js tB{Y k j {js8B I }? hIsR R$ tsR RBA j$%$stsR eR jjsR I js Z k 8ZtIBR I s}jsR st s% IsI RBA jBR R { BR I js ts% s{$? Bt R}s{$sj B JZ? R}BtI s js R? Z}j${sU "<BZR Bt t 8BR Zt } BAj 8s"
$R } tRs8$ t BR R I$ $ $ Bt sj %$s` JZ 8 R} sAs {Bt sj B I -} { s{$? Bt utB 8$ IB }B JZ ks YsA? s RBA %$%$IB s ZtB I RBR %$s` R $t }jst s $BR sZtJZ $t{BtR{$ t u k sj B I $t ? R eRT } {ZjsAs RBA js PB 8s t JZ j ks R}s{$sj I W AB $}P j R s ? s } B}ZjRsIB _ tR? t z t JZ YsA? s Y {YB JZ jBR 8$ 8A BR I j {jZA I sj $8B I$R}s sR t Zt $I? {ZjB {sK tB ?t {Bt Zts Asjs $}ZT jsIs t j R}s{$B I js q$ s s js NZts _ B AsR st ZtBR }B{BR {? sj{ZjBR 8 t sj R }s s 8BR s JZ js s{ j s{$? Bt t { Rs $s }s s I$RT }s s Zt } Bk { $j 8? sR sjj? s I js s% IsI I js q$ s R ? s s8A$? t RZh{$ t }s s - tI 8$ {Z }B k j I W AB $}P j }B j $t $B I js Asjs {B8B R$ PZ R t 8 8 jsIs I P Rs 7 }Y t s- NsR ts% R I j $ 8}B >qY q$8 7Y$}R d xH
wy9JZ$ IsD
s`B js $tJZ$ st } R t{$s I js eR jjs I js Z j <sj{? Bt $j ts $B RB s Zt t`s8A I
{s9sR t 8$ BR k skBR j? sR 8Z R sR I Zts $8} BAsAj As sjjs R}s{$sj 3B B s8s I js } j? {Zjs ej B tB I j F I$ >i Z t BP Y F I$ d MnH
© Los autores, 2001; © Edicions UPC, 2001.
(
* $t Bt s e$tR $t
<s{ 8Z{YB $ 8}B t Zts sjs-$s 8Zk 8Zk j `sts =t R{ZsI ? Bt I {s9sR qye $8} $sj R $ Z8} t js tB{Y $tht$ s t P t? ${s } R {Z{$? Bt I js ts% {B j$sts <sj{? Bt $j ts $B <st 7BjB RZ $t ? }$IB }$jB B $t t s AZ js j { {B t 8$ B sj$9stIB 8 s $sR 8st$BA sR k RB stIB j PZ B { Z9sIB I jsR As ? sR j? sR i$9BR {Bt s}${sIBR k {B8}j `sR s{ BAs{$sR {B8} tRst RZR %stBR $t t BR }B {Bt { s j R$R 8s I $8}ZjR$? Bt JZ I A ? s jst9s jBR 8? sR sjj? s I js % jB{$IsI I js jZ9 s s%? R I jBR R$tZBRBR {B IB R I j Y$} R}s{$B Vj ZtsR $RjsR I jZ9 Z Ast j 8stRB I j B{? stB I js tB{Y U jBR { t jj st R Ys{ R j? sR I jBR {s9sR $8} $sj R JZ Ys{ t 8 jjs t j R{ZIB I t ? s I j <sj{? Bt ej {B8stIB A jI s Zs Is {Bt RZIB P ? B RZ Ps sj I R $tB qBIB R ? s } I$IB B {sR$ VP Bt stIB Zts -$ Zs } BAsA$j$IsI I RZ} %$% t{$s ud t n 1d R ? Zt s}Zt s j h j stI B$I ]n_!u <st RZ8 j <sj{? Bt $j ts $B t j $t $B I Zt {s8}B I sR B$I R NBR sR B$I R {Z }BR I s8sK tB %s $sAj {ZksR I$8 tR$Bt R sAs {st I RI R{sjsR $tP T $B R sj { t ? 8 B YsR s jBR d ((( ,8 I I$? s8 B {BtR $ Zk t j$JZ$sR I js PB 8s{$? Bt I Zt R$R 8s }jst s $B eR BR s sIBR PB 8sIBR t js 8$R8s t AZjBRs t js JZ R 8BI jst R jjsR k }jst sR tB }BR t 8sRs RZh{$ t }s s t s }B R? RBjBR Zt jjs8sIB {$t Z ? Bt I sR B$I R ej I? A$j sA s9B s%$ s B $B tB R RZh{$ t 8 t $t tRB {B8B }s s j$ s j R$R 8s et Zt $ 8}B {B B jBR I$% RBR P s 8 t BR R I$R} RstU j {s8}B I sR B$I R R I$R s et j Z ?t${B {$t Z ? Bt I sR B$I R {BtB{$IB YsR s js P {Ys j -$R t t jsR B A$ sR I s k F? ? Z}$ t tZ R B 7$R 8s 7Bjs @ js I$R st{$s 8 I$s t {B8}Bt t R R R $8s t ZtBR d(N ,8 5<sA ? s sj sIB j R$tZBRB %Z jB s AB IB I j <sj{? Bt $j ts $B jBR {$ {Z$ BR I j stI B$I I } B B{BjB k R$t Zjs s Zsh R sR ]n_!2 WB -$R B s -}j${s{$? Bt s RZ ? Bt s R $8s{$? Bt I js } BAsA$j$IsI I RZ} %$% t{$s t Zt {s8}B I sR B$I R {ZstIB jB % IsI s8 t I$P? {$j R {Bj$R$Bts {Bt ZtB !
WB R ? R j Z ?t${B sR} { B I R s{sAj I R s R {Z t{$s JZ R$t jZ s s IZIsR }BI ? s }sRs s jBR stsj R I js {$t 8s B sP? s }B RZ Y$R ? B ${s {Bt{ t s{$? Bt I B R {$ t ? h{BRU j {s s{ ? R ${B BD js 9Z8A$IB I jBR 8B B R I $8}ZjR$? Bt I jsR ts% R wJZ t j hj8 R } B}s s }B j %s{? } { }{$? Bt I js sk { B $s I R{ $ s }B jBR j? sR wJZ R I R}js9st s 8Z{Ys 8 tB % jB{$IsI JZ js jZ9D js sj$9s{$? Bt I s{ BAs{$sR R 8 `st R sj %Z jB I Zt s%$? Bt B js } B}$s } R t{$s I Zt I } IsIB wZt $t8 tRB ZRstB JZ s }Zt B R ? s I t Zjj$ sj <sj{? Bt $j ts $B k s Bt I sR B$I R 5eR j? B ${B RZ $}Zjs{$? BtD t Zt jZ s st }B{B P {Z t sIB {B8B Zt {$t Z ? t{Bt s Zt I } IsIB t Zt t B tB {s t I } RsR2 +Z$9? sR RZ I$ s R j$8$ s $t ? }$IBR k I RsPB ZtsIBR %$s` BR 5O {? B8B Ys jj sIB YsR s sjj? 2 5V{sRB Ys t$IB } B t$ B R2 57 t{Z t s RBjB t Rs $Rjs I j B{? stB {? BR8${B {B8B Zt $t Bt sj? s{ ${B2 et R {s}? ZjB $t t s 8BR stsj$9s {Bt I sjj sj ZtBR I R BR sR} { BR Ns -$R t{$s I j {$t Z ? Bt I sR B$I R Rs 8$ ? sIs I P s 8 t BR B{BRBR JZ Ist9st sj I IB I j 7Bj R { I A$Is s js $t4Z t{$s s%$ s B $s I j $ st F? Z}$ JZ }s { YsA $tY$A$IB RZ s jZ $ts{$? Bt k js {BtR$ Z$ t PB 8s{$? Bt I Zt {Z }B I 8skB R I$8 tR$Bt R * RI j I R{ZA $8$ t B I ] R j sR B$I I 8skB s8sK tB t t B I dM(d R Yst {s sjB sIB ZtBR 1 ((( I R BR {Z }BR @
© Los autores, 2001; © Edicions UPC, 2001.
1 =ts BI$R s t j R}s{$BU I j et } $R sj <sj{? Bt $j ts $B
d
3$ 1 d ej <sj{? Bt $j ts $B {Bt% $IB t $t R} sIB s} $ $%B I Zt ? s%$IB I } IsIB t RZ $8s $ts $s Bt I sR B$I R YZ$Is I Zt w$8} BAsAj D {$t Z ?
1 d
]$t{B {Zs B R IBR ZtB gy t${$? Bt
ej R}s{$B js Z ?j $8s P Bt s =t 8ZtIB %$ t {ZkB {js8B Ys I R} sIB jsR stR$sR I -}jB s{$? Bt k j R t $IB I js 8s s%$jjs * RI st{ R sj R j k tIsR {Y$tsR }sRstIB }B P T t{$sR -}j? {$ sR sj %$s` s js NZts } R t R t j }B 8s ? }${B Y$tI? Z sYsAs s s j %Z jB R}s{$sj Ys {BtR $ Z$IB Zt 8s {Z t t j PBj{jB k t js j$ s Z s Zt$% Rsj et RZR $t${$BR {B8B 8 B % Y? {ZjB }s s s ${Zjs Zts R? s $ s RB{$sj {Bt js BR st RBA Rsj$ t R {B8B j ${ B8 sR > ${ B8? sR d x(H I zBj s$ B ej s% t Z B 7$8}j${? R$8ZR >* sA t Z T j${Y 7$8}j$9$RR$8ZR dEE H I F F p $88 jRYsZR t _BR $B 8 t j %Z jB R}s{$sj R Ys $ $IB {B8B }$js $tI$R{Z $Aj I js {$ t{$s R} {Zjs $%s I jBR R$ jBR y k Ns NZts j sR B I 8skB I$? s8 B s}s t %$R$Aj t js BR{Z $IsI I js tB{Y Ys {BtR $ Z$IB ZtB I jBR I R $tBR 8? sR %$R$ sIBR t js 8 t j$ s Z s I {$ t{$s h{{$? Bt R $8$ tIB Zt s8}j$B sAst${B I 8? BIBR k I$R}BR$ $%BR }s s j %$s` VR? NZ{$stB I 7s8BRs s I R{ $A t <$R B $s % IsI s >z s <$R B $s d1(H j %$s` JZ `Zt B s RZR {B8}sK t BR jB jj %s s js NZts $8}ZjRsIB }B j %$ t B q sR j }s ? t R$R sA$ B }B j BR{Z st $R8B I js IsI 8 I$s j $t ? R }B jBR %$s` R {? BR8${BR R B8s {Bt sZ t j ts{$8$ t B e` 8}jBR tB sAj R RBt ! jstIB PZ $BRB >dx(EH I NZIB%${B V $BR B IBtI j }sjsI? t ! jstIB A $B I s8B R{s}s s js NZts s {Z} s RZ {B IZ s t Zt {s B I PZ B $ sIB }B {sAsjjBR B kR $Z8 ]BR8B s}Y${Z8 >dEn;H IBtI j {? j A sR ? BtB8B FBYstt R }j ts s t {js% I RZ K tB Zts %$R$ s s tZ R B Rs ? j$ }B 8 I$B I s R 8? s ${sR =tBR {$Rt R sI$ R sIBR } 8$ t sj 8 s $B *B8$t B pBt9sj R }Bt j }$ t js NZts t js R? s $ s qY st $t Y BBt >dEnnH I j A $ ? st${B 3 st{$R pBIb$t qs8A$? t pB P $ I V Z [ t js Y$js st NBR 8s s%$jjBRBR
%$s` R }B s Zs k }B $ s jsR {s8}sK tsR k sj R s% t Z sR I j As ? Bt I [ Zt{YYsZR t sj
© Los autores, 2001; © Edicions UPC, 2001.
1
* $t Bt s e$tR $t
{B8B ? j 8$R8B s{BR Z8A sAs ts s AB jjs t 8stB t j {? {ZjB I RZR s8$ BR
>GZtI As
i $R t 9Z GsRR ZtI 9Z 3 jI9Z ZtI jZR $ VA t Z d MEH jj %s sj } B s Bt$R s s js NZts t IBR B{sR$Bt RU t js } $8 s RBA Zts }jst s I `ZI? sR wgJZ R YsA? s t BR{sIB t B tB Bt s ZtB I jBR {Z tBR I js NZts D k t js R ZtIs s sR sIB }B js PZ 9s I Zt {${j?
Ns %$sA$j$IsI I j %$s` s js NZts js $t BIZ{ }B % 9 } $8 s j hj? BRBPB A $ ? st${B FBYt G$j,$tR t js { s I${$? Bt I RZ BA s I I$%Zj s{$? Bt
qY *$R{B% k BP s W b GB jI
>dEnMH IBtI
s% t Z s JZ Zt st }? s`s B B Zt I$R}BR$ $%B %Bjst R ? st sj ? Zt I? s {s}s{ R I jj %s sj YB8A YsR s RZ RZ} h{$ y8}ZjRsIBR }B j sZ I js %BjZ{$? Bt {tBj? B ${s jBR R{ $ B R I j R$ jB y 8}$ 9st s I Rs Bjjs s Z8 t BR IBtI js {$ t{$s k js ? {t${s s $t{Btst } B R$%s8 t s js 8s $s VR? t
*Bt FZst
>dMd H I NB I
k Bt R R} {Zjs {Bt js }BR$A$j$IsI I jj s s
js NZts s AB IB I Zts 8? sJZ$ts I %s}B 8$ t sR JZ eI s Vjjst _B t
Ns s% t Z s R$t
$ Zsj I Zt sj <stR _Pssjj
>qY =t}s sjj j I VI% t Z BP Bt <stR _Pssjj dMnxH } R t s
Zt %$s` t jBAB YsR s j Rs ? j$ R =t {Z RB Z $j$9sIB }B %s $BR sZ B R R j ZRB I RZR st{$sR JZ } j t js s% IsI e` 8}jBR tB sAj R jBR {BtR $ Zk t >dMx H I Vj -stI *Z8sR B js 8? ${s Y BBt d (dH I j } Bj? h{B < A }st sjjs s%$ s B $s
=t %Bks s r js NZt NBR } $8 BR YB8A R t js NZts >qY 3$ R t $t p G jjR IBtI Zt R{ZIB I {s%B $ s Ys{ jsR % { R I
s`B js $t4Z t{$s I jBR sAs`BR I jBR }$Bt BR I js sR Bt? sZ ${s BtR st $t e qR$Bj,B%R,k iBA < pBIIs I < 8stt F !A Y B G tY %Bt sZt k sR j jst9s8$ t B I jsR
} $8 sR AB8AsR %Bjst R zT1 sj 8stsR IZ st js yy pZ s ZtI$sj jBR 8B B RT{BY }sRst s {BtR $ Z$ j 8 {st$R8B A? sR${B I j %$s` R}s{$sj }jsR8sIB t Zts $tht$IsI I tB% jsR I j ? t B Os sK tBR st R t jBR sjAB R I js sR Bt? sZ ${s FZj R z t sIB} stIB jBR {BtB{$8$ tT BR -$R t R t js ? }B{s $I s j Ps8BRB {sK tB ?tT} Bk { $j JZ t% ? s s RZR } B s Bt$R sR s js NZts R ? Zt js BI$R s ts sIs t
* js q$ s s js NZts 1 ! BR 8ZtIBR
>* js q s r js NZt dMExH k t
Vj I IB I js NZts
>VZ BZ I js NZt dM (H * Y {YB }Z I {BtR$I s R {B8B js {Bt $tT >N:sZ 8BtI BZ j R ? s R 8}$ R
Zs{$? Bt ts Z sj I Zts BA s } { I t
I js NZt j 7Bj $j dEx TdE 1H I ]k stB I
s{ IBtI j sZ B Ys{ 8 t{$? Bt s Zt
I$R}BR$ $%B $8}ZjRsIB }B {BY R I }? Bj%B s I $ t${$? Bt } B R$%s JZ }BI ? s {$ s R {B8B } {Z RB I jBR {BY R }B s}sR {Bt 8}B ? st BR
n
ej Z ?j $8B {$B I j R$ jB {B$t{$I$ tIB {Bt j jst9s8$ t B I j } $8 Rs ? j$ s $h{$sj wjs RBtIs RB%$? ${s
7}Z t$,
j ; I B{ ZA I d x D k {Bt j } $8 s $9s` $}ZjsIB t B B
ej t$sj p B ? j$r R wdMEdTd nMD PZ j } $8 B t jj %s js tB% js I z t sj {$t t j {B B N %Bks IstR js NZt >d (1H q sR j } $}jB jZts sAB Is ? s s8A$? t j %$s` sj 7Bj t Zts R s8A? B ${s ts% T t t zBks s s% R j:$8}BRR$Aj >d (;H n NBR {BY R % t? st R$ tIB ZRsIBR t ! $ t I RI j R$ jB y Os Zts st $ Zs j k tIs {Y$ts s $AZk s Gst <Z j YsA s{B}jsIB Zt R$R 8s I {BY R s Zts R$jjs k gYsA I R} sIB Ys{$s jB I R{BtB{$IB _ R s JZ js -$R t{$s I jBR {BY R s {BtB{$Is t eZ B}s RZ }B t{$sj A? j${B PZ } ? s{ ${s8 t $ tB sIB YsR s j R$ jB zyyy {ZstIB jsR B}sR A $ ? st${sR I R s{sIsR t js ytI$s PZ Bt sRsj sIsR {Bt R $}B I I$R}BR$ $%BR _BR $B 8 t j } B}$B `? {$ B A $ ? st${B $t{B }B ? B j ZRB I {BY R t js Z s {Bt s Ws}Bj ? Bt sR? {B8B t js pZ s I js ytI } tI t{$s I jBR eR sIBR =t$IBR 1
© Los autores, 2001; © Edicions UPC, 2001.
1 =ts BI$R s t j R}s{$BU I j et } $R sj <sj{? Bt $j ts $B
n
8ZtIB w j sjZt$9s` I js ts% tB s8 ${sts V}BjB y j 1( I `Zj$B I d E D Ys RZ}Z R B Zt $ B }s s jBR R{ $ B R I {$ t{$s h{{$? Bt JZ$ t R Yst s ${ZjsIB tB% jsR {Bt Zt {js B sRPBtIB sj$R s AsRsIB t js {$ t{$s NBR ` 8}jBR RBt $ttZ8 sAj RU 1((d Zts BI$R s I j R}s{$B >1((dU V 7}s{ !IkRR k d EMH B ]$ s {Bt is8s >i tI 9%BZR b$ Y is8s d nH I V YZ ] ]js , et {s? Is j$A >3sjj$t 3 d MMH I NB$R { sR Z`BjI B js $jB ? s $t${$sIs {Bt s B`B >i I s R d nH I $8 7 stj k iBA$tRBt WB sAj R s8A$? t 3sR R I s% IsI >_YsR R BP p s%$ k d M H I *st 7$88BtR Zt YB8 ts` s jBR YB8A R JZ }s ${$}s Bt t j jjs8sIB } B s8s R}s{$sj eR st }sRB }s s js YZ8st$IsI j %$s` s js NZts tB RZ}Bt 8? sR JZ Zt }sR B }B jsR B $jjsR I j $t8 tRB B{? stB {? BR8${B Ns NZts Ys 8} 9sIB s JZ Is I 8sR$sIB { {s yt{jZRB j 7$R 8s 7Bjs t RZ {Bt`Zt B Ys JZ IsIB } JZ K tB {B8B 8? t$8B }s s js 8 t { s $%s I jBR R{ $ B R I {$ t{$s h{{$? Bt JZ$ t R Yst $8}ZjRsIB RZR ts% R 8? sR sjj? s I jsR P Bt sR I j 7$R 8s 7Bjs t BA sR 8s R sR {B8B Ns Z s $t 8$tsAj >qY 3B % Gs d ;H I FB <sjI 8st <Z %B I * s ? Bt >* s Bt:R e d M(H I iBA N 3B bs I B et j B{? stB I js tB{Y >yt Y !{ st BP W$ Y d M;H k jsR RZ{ R$%sR t sR I Rs 8BtZ8 t sj R $ I j { t B sj? s{ ${B I j tB s8 ${stB p B k tPB I 7Bt sj ZtBR ` 8}jBR I j ZRB I 8B B R I PZR$? Bt tZ{j s AsRsIBR t } Bk { BR } -$R t R {B8B js tsIs sR Bts% *s IsjZR I js $ $RY yt }jst s k 7B{$ k wd nTd D js ts% ! $Bt I$R K }B qY BIB qskjB 3 8st *kRBt k {BjsAB sIB R B j } Bk { B ZRRs I is8` I$R K tsIB }B i G ZRRs I k sRB{$sIBR ej Z ?j $8B RjsA? Bt I js {sI ts jB {BtR $ Zk t I$% RsR tB% jsR AsRsIsR t } Bk { BR sj tsT $%BR {B8B }B ` 8}jB j ZRB I js t ? s I j %s{? B js I tB8$tsIs } B}ZjR$? Bt {Z? st ${s $t BIZ{$Is }B ]Ys j R 7Y ^ jI t NsR { ? Bt${sR I {VtI b >qY {VtI b ]Y Bt${j R d MnH k Z $j$9sIs s8A$? t }B V YZ ] ]js , t ]? st ${BR I js j `sts q$ s >qY 7Bt R BP *$R st es Y d MEH B t j ZRB I js } R$? Bt I js sI$s{$? Bt RBjs }s s js ts% s{$? Bt R}s{$sj {ZkB B $ t R 8Bt s s jsR R} {Zjs{$Bt R I 3 $I $, qRstI wd 1;D k {Zks R t{$s {BtR $ Zk j 8 {st$R8B AsR I js BR {B8B Ns *s8s JZ jj %? B :ej Vj8s: >qY NsIk bYB 7s$j I : Y 7BZj: d E(H B _$ tRs s9Zj {Z t s YsR s IBR >qY$t, jZ ]BZt qbB d EnH I ]B Ibs$t 78$ Y B j 8s $R sj js B ej %$ t B I j 7Bj >qY G$tI P B8 Y 7Zt d E1H I V YZ ] ]js , 1 1 * js q$ s s g s RBB8
=ts }s sI$R? s{s 8sK tsts I dEEE t js {s8}$K ts $t j Rs =t s{{$I t ts Z sj As`B j RBj sA sRsIB js {s? Is I Zts 8st9sts k RZR $t R} sIsR {BtR {Z t{$sR qsj PZ j $8}s{ B t js 8 t { s $%s I W b Bt JZ js {s? Is I Zts 8st9sts R ? Zt {Z t s js j k tIs I R t{sI t? B RZR Ps8BRsR {Bt` Z sR RBA j 8B%$8$ t B I js NZts k jBR }jst sR JZ sK tBR 8? sR s I { $R sj$9s Bt t js j k I js s%$ s{$? Bt Zt$% Rsj _ R s RZ t$B }B{B }BI? s Ys{ W b Bt }B %$ s js {s? Is I js 8st9stsU Zt {Z }B j$A I BIs RZ` {$? Bt R } {$}$ s $ 8$R$Aj 8 t Ys{$s j RZ jB s s? IB }B js PZ 9s I js s% IsI eR {? j A }$RBI$B I js %$Is I W b Bt Zt s}B ? B tZ %s jZ9 t RZR $t% R $ s{$Bt R RBA j 8B%$8$ t B I jBR {Z }BR ws}s I sj ? sj$R$R I js sk { B $s R Z$Is }B Zt 8? B%$j } B}ZjRsIB s I$% RsR JZ B B {Y${Y? BtD et RZ st? % jB{$IsI R w3$ 1 1D W b Bt {B8} BA? B JZ js {s? Is R s Is sj sZ8 t s js % jB{$IsI I
© Los autores, 2001; © Edicions UPC, 2001.
;
* $t Bt s e$tR $t
3$ 1 1 q sk { B $sR I R{ $ sR }B Zt BA` B jst9sIB s I$P t R % jB{$IsI R I RI Zts {$ s sj Z s R ? Zt Zt st${s t b Bt$sts V _ 3 t{Y d MD I$AZ`B I j } B}$B W b Bt wsIs} sIB I {? jst9s8$ t B ]Bt Zt $8}ZjRB $t${$sj RZh{$ t Zt {Z }B }Z I jj s s }Bt R t B ? A$ s t Zts R} {$ I {s ? Is {Bt $tZs $8}s sAj JZ tZt{s jj s s 8s $sj$9s R _s s jsR I$8 tR$Bt R k 8sRs I js q$ s Zt {Z }B jst9sIB s M ,8
b R P { ? Zs Zts B ? A$ s sRst k {$ {Zjs U
j {Z }B
}sRs s {Bt% $ R t Zt Rs ? j$ s $h{$sj I tZ R B }jst s
7$ R sZ8 t s js % jB{$IsI I
jst9s8$ t B js sk { B $s R B ts 8? sR k 8? sR j? } ${s I sj 8st s JZ }s s Zts % jB{$IsI I dd 1 ,8
,
b R
js sk { B $s R {Bt%$ t Zts }s ? sABjsU j {Z }B I `s I R s j$ sIB s js eR s % jB{$IsI { ? ${s js t { Rs $s }s s
RZ} h{$ R k R }$ I t j R}s{$B $tht$ B
jZI$ j P? B sA s9B s%$ s B $B I Zt }jst s R I tB8$ts
% jB{$IsI I R{s}
B I
PZ s
Ns q$ s R Zt }jst s js $%s8 t } JZ K tB {Bt I$8 tR$Bt R 8BI R sR k Zts 8sRs 8Zk $tP $B s js I jBR $ st R F? Z}$ B 7s Z tB $ t sR JZ BA` BR {B8B js NZts B j } B}$B s w
s RBB8
R ? Zt jBR ts $%BR I j }jst s B`B $8s $tsIBR }B eI s i${
Z BZ YR t s R
jsR {? j A R s% t Z sR I FBYt ]s $t${$sIsR {Bt
=ts } $t{ Rs I s >V _ $t{ RR BP
d d1HD } R t st % jB{$IsI R I R{s} sj B 8 tB R R{s}s I js s% IsI I sR BR {B8B j 7Bj 8Z{YB 8? sR 8sR$%BR {BtR $ Zk Zts s s 8? sR {B8}j `s w]ZsI B 1 dD
]sIs }jst s t %$ ZI I RZR {s s{ ? R ${sR P? R${sR w R I {$ RZ 8sRs k RZR I$8 tR$Bt RD }BR Zts % jB{$IsI I R{s} I 8$tsIs 7Z %sjB } 8$ }B ` 8}jB {Bt sR s k stsj$9s js %$sA$j$IsI I jBR 8 {st$R8BR I } B}ZjR$? Bt I R{ $ BR t j s}s sIB st $B $8s $tsIBR }B jBR I$% RBR R{ $ B R I {$ t{$s h{{$? Bt t RZR Pst ? sR ${sR { s{$Bt R VR ? j {${j? Bt JZ stR}B s sj As ? Bt I [ Zt{YYsZR t s js NZts I$P? {$j8 t }BI ? s jj %s s {sAB sj 8} Rs =t YZ s{? st }Z I sj{st9s jBR n(( ,8
b Y
} BIZ{$ tIB P { BR I %sR sIB R sZtJZ R$t jj s s $8}ZjRs
t$t ? Zt {Z }B s js % jB{$IsI I R{s} * Y {YB js sR{ tR$? Bt s st sj Z s I sj ZtBR {Z }BR
© Los autores, 2001; © Edicions UPC, 2001.
1 =ts BI$R s t j R}s{$BU I j et } $R sj <sj{? Bt $j ts $B
x
]ZsI B 1 d p s% IsI k % jB{$IsI I R{s} Ns % jB{$IsI { ? ${s s js JZ I A $8}ZjRs R Zt BA` B }s s R{s}s I j {s8}B s%T $ s B $B I Zt }jst s B Rs ? j$ R I tB8$ts % jB{$IsI I R{s} _Z I I 8$ts R {B8BU z jB{$IsI I R{s} ) w1 s% IsI sI$BDd>1 ) wd!nn d( d( 8sRsb sI$BDd>1 w8bRD w, D w8D IBtI j sI$B {B R}BtI s js I$R st{$s 8 I$Is I RI j { t B I j }jst s YsR s j jZ s I jst9s8$ t B ]ZstIB ? R R sj$9s t Zt }Zt B I js RZ} h{$ {B R}BtI sj sI$B I j }jst s Ns sAjs R$ Z$ t 8Z R s Zts {B8}s s{$? Bt t js s% IsI k js % jB{$IsI I R{s} }s s sj ZtBR {Z }BR I j 7$R 8s 7Bjs 7 sI`Zt st jBR %sjB R {B R}BtI$ t R s jBR tZ % }jst sR IBR Rs ? j$ R w3BABR k js NZtsD Zt sR B$I y{s BD k j 7Bj w?
VR B {Z $B z tZR q$ s NZts s 3BABR ? y{s B F? Z}$ 7s Z tB = stB W } ZtB _jZ ? Bt 7Bj
w q D (, (E (, M1 d d, 1n d( 1 (, dd 1, (( d( d, d( dn ndM x, d d;, E d , 1 (, (d n, nn d(x
sRs
w ,8D 13;n E3(xd E3n M d3 nM n3n ; dn, x (, d3n M E(3((( 1x3;(( 1;3 x( d3;(( E, E d(x
isI$B
p s% IsI
w D (, ;d (, d d (, d (, n ;, x d( ; d, ; d( ; 1, x; d, (M (, 1 d, d; (, 1d 1 ,
z jB{$IsI w ,8bRD ;, ;n d(, ; dd, 1 1, ;d x, d( (, (d ;, ; d( ; x , E nx, 1d, ; 1n, x 1, ;( Ed ,
z jB{$IsI R I R{s} I I$P t R {Z }BR I j 7$R 8s 7Bjs w q ) sRs I js q$ s ) x M d(1; , ) s% IsI t js RZ} h{$ I js q$ s ) M 8 R1D , b
Ns % jB{$IsI I R{s} {BtR $ Zk Zt j 8 t B $8}B st t js 8B PBjB ? s }jst s $sU I 8$ts j $}B I s 8? BRP s JZ Zt I 8$tsIB }jst s }Z I }BR NsR s 8? BRP sR }jst s $sR R ? st {BtR $ Z$IsR }B sR R I I$% Rs ts Z sj 9s NsR 8Bj? {ZjsR JZ {BtT h Z st R BR sR R R I R}js9st {Bt Zts % jB{$IsI 8 I$s JZ I } tI I js } B}$s 8} s Z s I j sR k R $t% Rs8 t } B}B {$Btsj s RZ 8sRs VR? t js RZ} h{$ I js q$ s jsR % jB{$IsI R 8Bj {Zjs R I j B-? tB k I j t$ ? B tB RBt 8Zk $tP $B R s js % jB{$IsI I R{s} }B jB JZ R BR sR R } 8st { t t tZ R s s 8? BRP s 7$t 8T As B B sR 8Bj? {ZjsR 8? sR j$ sR {B8B jsR I Y$I ? B tB B Y j$B } R t st % jB{$IsI R 8skB R k $ tI t s R{s}s I tZ R s s 8? BRP s et jBR $ st R sR BRBR F? Z}$ k 7s Z tB }B {Bt s jsR j %sIsR % jB{$IsI R I R{s} } 8$ t t RZR st{$sj R {st $IsI R I Y$I ? B tB k Y j$B
© Los autores, 2001; © Edicions UPC, 2001.
E
* $t Bt s e$tR $t
{B8B P s 8 t BR I s ? ABj R B `sIBR R } BIZ{ }B js I$P t{$s I } R$? Bt t j $t $B I j B tsIB k js s 8? BRP s JZ jB {$ {ZtIs JZ sZtJZ }Z I jj s s R I ZtBR d(( 8$j$As R w JZ$%sj t sj sZ8 t B I } R$? Bt sj RZ8 $ R d 8 As`B j s ZsD RZj s $tRZh{$ t }s s JZ jsR I$% $IsR R? s $ sR I NZ{$stB I 7s8BRs s k p V Z [ RZj t P? R${s8 t %$sAj R ! BR $t t BR Yst jj %sIB s Z $j$9s stI R }? s`s BR %BjsIB R {B8B jBR {$Rt R s8s R sIBR I qY st $t Y BBt B j } B}$B %Z jB s js NZts s AB IB I Zt Y j${? B} B {B8B js s FZI$ Y $j t Ns t I j 8sK tsts >qY qB8B Bb _ B}j d E(H et s8ABR {sRBR js sZR t{$s I s$ t j R}s{$B Ys{ $t%$sAj j 8 {st$R8B A? sR${BU j 8}Z` } B}${$sIB }B js $8}ZjR$? Bt I s$ t R t $IB B}Z R B 8 I$st js s{{$? Bt I sjsR B Y? j${ R {B8} tRs RZ } RB } 8$ $ tIB js j %s{$? Bt =t s9Bts8$ t B R$8$js tBR jj %s s PZ s j }jst s8$ t B I eI s Vjjst _B t RZ V% t Z s R$t $ Zsj I Zt sj <stR _Pssjj IBtI Zt jBAB Ys{ jsR % { R I 8 I$B I stR}B }s s j %$s` s js NZts ej j 8 t B {js% t js sR{ tR$? Bt I Zt jBAB R j jjs8sIB js I$P t{$s I I tR$IsI R t IBR 4Z$IBR w j sR 8}Z` I V JZ? 8 I R w]ZsI B x dD VJZ? I j $t $B I j jBAB k j s$ JZ jB BI sD } BIZ{ Zt 8}Z` JZ {Bt s R s j } RB I j jBAB 7$t 8As B j R}s{$B %s{? B {s { I s$ }B jB JZ j 8}Z` sR{ tR$Btsj I Rs}s { }B {B8}j B eR 8? sR js sZR t{$s I } R$? Bt t j %s{? B } B}${$s ? s js -}jBR$? Bt I j } B}$B jBAB VZtJZ ZtB s8}B{B $ t }B JZ? { Z9s R R}s{$B %s{? B =t {Z $BRB ` 8}jB st A $T jjst 8 t $8s $ts $%B {B8B sARZ IB jB {BtR $ Zk N R -$j R I js q >dMM H I VtI ? NsZ $ IBtI jsR $t{B8BI$IsI R I j %$s` s s%? R I j %s{? B -$R t t js q$ s k js NZts R RB st s{ {stIB 8}B sj8 t js NZts YsR s js }BR${$? Bt I js s 8? BRP s R gZ $j$9stIB $8st R $ st R qs8A$? t js R? s $ s {Bt 8}B ? st s I BA 7Ysb NBR sR BtsZ sR Ys s}$ t BR >qY is I VR BtsZ R d MEH R Ysjjs t {BtRBtst{$s {Bt R }jst s8$ t B Ns tB% js stR{Z t Zt Zt$% RB I P? R${s sj ts $%s IBtI j %sjB I j t? Z8 B R -s{ s8 t n eRs {$ {ZtR st{$s B $ $ts js -$R t{$s I Zts s 8? BRP s t%Bj% t {B8}s $Is }B IBR }jst sR JZ R ? Zt js tB% js Ys{ Ps{ $Aj j %$s` t jBAB I Zt 8ZtIB sj B B et Zt $t t B }B jZI$ sj ZtBR } BAj 8sR I j jst9s8$ t B B BR sZ B R I j ? t B Yst RZ $IB js -$R t{$s I 8s $sj R st $ s%$ s B $BR B } j t R I js s% IsI =t } { I t jB {BtR $ Zk V{ BRR Y BI$s{ >dMM(H I _ {k p IBtI j sZ B Ys{ 8 t{$? Bt I Zt 8s $sj B}s{B s js s% IsI qs8A$? t < p G jjR t RZ Ps8BRs NBR } $8 BR YB8A R t js NZts s $AZk js }jsZR$A$j$IsI I Zt %$s` s js NZts s jsR } B}$ IsI R I Zts RZR st{$s B}s{s s js s% IsIU "qBIsR jsR RZR st{$sR {BtB{$IsR RBt : stR}s t R: s js s%$ s{$? Bt _Z I t 8}j s R }st sjjsR I %s $sR {jsR R }s s $8} I$ js t sIs I js jZ9 j {sjB js $t4Z t{$s j? { ${s I j 7Bj B j {sjB I js q$ s R }Z I $8} I$ {Bt j? s8$tsR I 8 sj JZ jBR skBR I s {Bt$ jj Z t s sj B {Zsj BA` B } B tsIs }Z I {B s js s s{{$? Bt s%$ s B $s I j 7Bj B I js q$ s 7$t 8As B RZj s I$P? {$j -}j${s }B JZ? tB -$R tsIs JZ R$ %s }s s jjB " Ns sZIs{$s I ]s%B ZRstIB Zts sj s{$? Bt I %s $BR 8 sj R {Bt Y j$B j jj %s s I R{ZA $ Zt tZ %B 8s $sj AsZ $9sIB {B8B {s%B $ s JZ s}st sjjs js s% IsI i {ZA $ tIB RZ ts% RP? ${s {Bt ZtsR } R$stsR t BjjsAj R As t$9sIsR {Bt {s%B $ s ]s%B k IPB I {BtR$ Z t jj s s js NZts sA $ tIB k { stIB sj ts $%s8 t jsR } R$stsR }s s Z$s js ts% Ns -$R t{$s I Zt 8s $sj {B8B js {s%B $ s {B8}B s ? s js %$Bjs{$? Bt I ZtB I jBR
© Los autores, 2001; © Edicions UPC, 2001.
1 =ts BI$R s t j R}s{$BU I j et } $R sj <sj{? Bt $j ts $B
3$ 1 n =t 8? BIB %BjZ{$Bts $B }s s RB s j $t %$ sAj %s{? B t js q$ s k js NZts NsZ $ -$j R I js q >dMM H I VtI ?
sRsIB t N R
} $t{$}$BR PZtIs8 t sj R I js P? R${sU js {BtR %s{$? Bt I js t ? s VR? R }BI ? s j %s Zt {Z }B {ZA$ B {Bt {s%B $ s k I `s jB {s } BIZ{$ tIB sAs`B R$t {BtRZ8$ t ? s 7$t IZIs {BtR $ Z$ ? s js 8s $sj$9s{$? Bt I j %$ `B RZ K tB I j 8B%$8$ t B } } ZB qs8A$? t Fs8 R j$RY t RZ {B}$js{$? Bt ]$ $ R $t 3j$ Y >d xxTd E1H $8s $ts js -$R t{$s I ZtBR I$R}BR$ $%BR jBR R}$tI$99$ R {Zks B s{$? Bt } 8$ t s B j$8$ts Zt {s8}B I s% IsI Ys{$ tIB }BR$Aj j I R}js9s8$ t B I {$ZIsI R t sR s jB js B I js psjs-$s _B I R s{$s j RZ K tB I js st $ s% IsI tZt{s I R} s ? s 8? sR sjj? s I jsR Pst sR? sR $8s $tsIsR }B js {$ t{$s h{{$? Bt qsj k {B8B {Bt{$A$? B e$tR $t sj jsAB s RZ B ? s t sj I js js $%$IsI js s% IsI js PZ 9s {Bt JZ Zts 8sRs s s s B s R j RZj sIB I js I PB 8s{$? Bt I j R}s{$B {sZRsIs }B js } B}$s } R t{$s I BA` BR {Bt 8sRs Ns st $ s% IsI I -$R $ I A ? s j$8$ts I${Ys I PB 8s{$? Bt JZ$ $ tIB js -$R t{$s I 8sRs t s $%s Zt {Bt{ } B JZ R{s}s I jsR P Bt sR I js P? R${s {BtB{$Is WB R I - sK ts }B {BtR$ Z$ t j sRB8A B I j P? R${B I j js B ] t{$s > j$ P d xnH I yRss{ VR$8B% sJZ `sIB I Zts - sK ts PB 8s I j %$ s{$? Bt $t{B8} tR$Aj R ? Zt jBR {? stBt R {j? sR${BR I RZ } BP R$? Bt _Z I t t{Bt s R s8A$? t B BR $8s $ts $%BR ZRBR I js st $ s% IsI t js BR {B8B Ns ABjs I A$jjs >qY $jj$s I sjj d EEH I yRss{ VR$8B% B t =t sRZt B I s% IsI >GYs pB R =} d xxH I V YZ ] ]js , qst RB } tI t }Z I RZj s }s s j R YZ8stB Zt Y? sA$ s IB sIB I Zts -{ R$%s s% IsI {B8B Zt 8ZtIB j$%$stB {Zks 8 tB s% IsI } B}B {$Bts Zt R{ ts $B $I? Bt B }s s sj$9s 8$j s{ BAs{$sR NsR -$ ZsR % jB{$IsI R I R{s} I sj ZtBR {Z }BR 8 tB R I j R$R 8s RBjs Yst } B}B {$BtsIB {Z $BRBR s Z8 t BR s I$% RsR ts s{$Bt R k } j? {ZjsR I j ? t B VR? }B ` 8}jB jBR $t ? }$IBR sR BtsZ sR I j hj8 +Z t BP jBBI >d EEH -} $8 t st Zts % IsI s
© Los autores, 2001; © Edicions UPC, 2001.
M
* $t Bt s e$tR $t
BI$R s IZ st Zts 8$R$? Bt I R{s JZ jBR jj %s s js RZ} h{$ I 3BABR ZtB I jBR } JZ K tBR Rs ? j$ R 8s {$stBR et Zts 8 8B sAj R {Z t{$s I {$I t {Ys s RZ R js $}Zjs{$? Bt JZ Bt }s s }s $ ? s t js ts% I R{s jst9stIB }s s jjB Zts 8Bt Is "sj s$ " w%sj s js -} R$? Zt 8ZtIB R$t s 8? BRP s {B8B 3BABRD Ns s% IsI I 3BABR R $tR$ t$h{st _BI 8BR I IZ{$ RZ %sjB s }s $ I RZ sI$B 8 I$B ZtBR dn, x ,8 k RZ I tR$IsI I j B I t I 1 b {8n Ns s s{{$? Bt s%$ s B $s t 3BABR RZj s R ZtsR 131(( % { R 8 tB JZ js s% IsI R ej jst9s8$ t B I Zts 8Bt Is sj s$ R sj$9s ? }${s8 t s Zts % jB{$IsI I ZtBR x 8bR et js } j? {Zjs j 8B%$8$ t B I js 8Bt Is 4 `s {js s8 t j Y {YB I YsA R hj8sIB t js q$ sU As`B js $I? {Zjs % jB{$IsI I R{s} I 3BABR st R? BjB dd 8bR js 8Bt Is RZ} s ? s jBR 13M(( 8 I sj $ ZI sR j jst9s8$ t B NBR sR BtsZ sR }B RZ }s I A ? st s 8s R I }s{$ t{$s k s Zs Is {sR$ % $t 8$tZ BR YsR s js {s? Is I j } JZ K tB BA` B wR$ j {YB I js ts% tB jB $8}$I$ sD ! B js B {Zks s{{$? Bt R R$ ? Zs s8A$? t t js $tY? BR}$ s RZ} h{$ I 3BABR R FZ B I R{BtI$ ><$I stI 7 ,H I V YZ ] ]js , et R s ts s{$? Bt Zt R}? s PZ $sIB t 3BABR $t t s jZI$ js %$ $jst{$s I Zts ts% I js 4B s }Bj${$sj V sj P { B k IsIs js }B{s s% IsI I 3BABR R 8st $ t j `BR I j {s8}B I %$R$? Bt I js ts% I R}js9? stIBR }B js RZ} h{$ I j Rs ? j$ 8 I$st js BR Rsj BR
VR B R,j$t <Z %B I * s ? Bt z7Td i 8Bj$tB qYsjsRRs q$ s
sRs w-( D (, x d, n n d( E
isI$B w ,8D (3((( n(3((( d( M, x d3((( E3n (
p s% IsI RZ} h{$sj w D n (( E, M d(d( (, 1 d, (E d
z jB{$IsI I R{s} w ,8bRD E; dMn ddx3x(( 1(d3d(( d, M dd, 1
qsAjs 1 d *s BR P? R${BR {B R}BtI$ t R s sj ZtBR R{ ts $BR I j Zt$% RB I js {$ t{$s h{{$? Bt {B8}s sIBR {Bt jBR %sjB R R R 3Z t RU R,j$t T $R$? Bt I s% IsI I <sj ]j 8 t <Z %B I * s ? Bt T <Z %B I * s ? Bt I iBA N 3B bs I z7Td T eR jjs I t Z Bt R I Ns k W$% t i 8Bj$tB T et jBR js $IBR I js tB{Y I ]Ys j R 7Y ^ jI qYsjsRRs T ]? st ${BR I js j `sts q$ s I V YZ ] ]js , wd ( ) 1 d(n( , } R t s js 8sRs I j 7BjD Vj ZtBR sZ B R I j ? t B Yst sRjsIsIB js s{{$? Bt s js R$tZBRs RZ} h{$ I sj ZtBR } JZ K tBR sR B$I R I j 7$R 8s 7Bjs {B8B t z stB t ? y{s B >7Z88 $8 $t y{s ZR d E(H I V YZ ] ]js , ej sR B$I ? y{s B dxEE }BR Zt I$? s8 B s} B-$8sIB I d, ; ,8 k Zts 8sRs d1 BjB (, x 8bR R $8sIs t d( , I 8s $sj ${B t 8 sj R 7Z % jB{$IsI I R{s} R I R? R$8$js s js % jB{$IsI {Bt js JZ Zt R YZ8stB }Z I $8}ZjRs R t Zt Rsj B % ${sj _B jB st B {B8B RBR $ t j } B}$B ]js , I Zt RBjB Rsj B j sR BtsZ s ]Bj$t 7Y s I }BI ? s R{s}s I js s% IsI I ? y{s B k sj{st9s js ts% _ B8 B JZ R Ysjjs s st R? BjB n ,8 I I$R st{$s _s I js s{{$? Bt I js tB% js et j B{? stB I js tB{Y I p B k tPB I stR{Z s8A$? t t js RZ} h{$ I ? y{s B NsR R $8s{$Bt R I js 8sRs I j sR B$I JZ A $tIs j
© Los autores, 2001; © Edicions UPC, 2001.
1 =ts BI$R s t j R}s{$BU I j et } $R sj <sj{? Bt $j ts $B
sZ B ZtBR ; d( , I Zt 8s $sj ${B t Y$ BTt? JZ j t Zt M(0 k RZR I$8 tR$Bt R RBt sj B $tP $B R s jsR s{ } sIsR YBk t I? s * Y {YB t js tB% js js 8sRs I ? y{s B RZj s R BIs%? s 8 tB sR j I R{ZA $8$ t B I j $t ? }$IB sR BtsZ s W$ j Gsj8Rj k JZ$ t }BRsIB RBA j 8$t? ZR{ZjB sR B$I I R% js RZ sRB8A BRs ts Z sj 9s YZ {s =ts tI t{$s I R s{$sIs8 t 8Zk - tI$Is t js {$ t{$s h{{$? Bt {$t 8s B ? sh{s k j %$R$%s R js sZR t{$s R$R 8? s ${s I {ZsjJZ$ P { B } BIZ{$IB }B j {s8A$B I s% IsI VR? }B ; ` 8}jB t js R $ I qz eR}s{$B d >7}s{ d d xT H js 8 tB s% IsI jZts d\E I js s% IsI R tB R s} {$s t jBR 8B%$8$ t BR I jBR sR BtsZ sR JZ RBt {s s{ ? R ${BR I Zt t B tB {Bt Zts s% IsI R$8$js s js R t jsR tB% jsR I j ? t B et R s BA s {j? sR${s I js j$ s Z s I {$ t{$s h{{$? Bt {Bt R? Bj$Is AsR {$ t ? h{s R ts s js - sB I$ts $s BI$R s I Zts -} I${$? Bt YZ8sts sj }jst s R,j$t Zt 8ZtIB I s}jsR st s% IsI (( t jBR }BjBR } B R$%s8 t IZ{$IBR YsR s jBR n t BIB I B s{$? Bt I j {ZsIB I j }jst s 7Z j %sIs B s{$? Bt wM( % { R js R {Bt Zt } ? dM 8$tZ BRD R R}BtRsAj I j s{Ys s8$ t B I j }jst s JZ } R t s Zt I$? s8 B {Zs B $sj I ( ((( ,8 k Zt I$? s8 B }Bjs I n( ((( ,8 NsR {BtI${$Bt R s8A$ t sj R I j }jst s RBt Bt s8A$? t - 8sRU Zts 8} s Z s 8 I$s R $8sIs t d;( 0 ] JZ Is jZ s s js PB 8s{$? I B{? stBR I 8 stB j? JZ$IB k s js {s? Is I t$ % I s8Bt? s{B 7Z st s8sK tB Zs Is R{sRs js{$? Bt {Bt jsR I$8 tR$Bt R I js q$ s 7$t IZIs R 8}s $ t s {Bt jBR $ st R sR BRBR F? Z}$ B 7s Z tB sZtJZ js j %sIs s% IsI I R,j$t }s { }B{B {B8}s $Aj {Bt Zt }jst s sR BRB ej j$A B {BtR $ Zk Zt R? Bj$IB ` 8}jB I R} {Zjs{$? Bt A$Bj? B ${s t j JZ R stsj$9st jsR {BR Z8A R k js {tBjB ? s I Zts RZ}Z R s s9s - s R t Zt t B tB I j %sIs s% IsI NBR 8 R,j$t$ sR $ t t s}s $ t{$s I ZRstB {Bt Zts jBt $ ZI I ZtBR ;( {8 k Zt I$? s8 B I x {8 7Z {Z }B R ? s R 8 t sIB k }BR %s $BR {B s9Bt R JZ AB8A st Rst s BIsR jsR - 8$IsI R =t sR} { B RB } tI t I js tB% js R j 8$ IB I jBR 8 R,j$t$ sR s jsR sj Z sR k js } ? s{ ${s $ tB st{$s I js { s I$8 tR$? Bt R}s{$sjU RZR YB s R {s { t I {YB }B 8B s RZ {s? Is W$ R$JZ$ s Yst I Rs BjjsIB j $ B {Bt s {B O R JZ x {8 }Z I t R$ t$h{s Zt sA$R8B t Zt 8ZtIB I (( / _B ` 8}jB R$ Zt 8 R,j$t$ s Z%$ s {sR}s ? R s $8}s{ s ? s {Bt s j RZ jB I R,j$t gs 1E 8bR =ts 4 {Ys jst9sIs s x( 8bR I RI Zts sj Z s I x {8 R } {$}$ s ? s {Bt s j RZ jB s jBR n, M 8$j$R ZtIBR I j jst9s8$ t B k s Zts I$R st{$s I R? BjB d {8 I j jZ s I jst9s8$ t B Vt sj R } R} { $%sR }s { j? B ${B JZ Zts {$%$j$9s{$? Bt {B8B js 8 R,j$t$ s Ysks tPB{sIB RZ $ 8}B j$A s B sR s{ $%$IsI R
$R$? Bt I s% IsI > $RR$Bt BP p s%$ k d x;H I <sj ]j 8 t {BtR $ Zk Zt }Zt B I $t4 -$? Bt
eR jjs I t Z Bt R >W Z Bt 7 s d EEH I Ns k W$% t k <Z %B I * s ? Bt I iBA N
3B bs I - s}Bjst jsR {BtI${$Bt R I %$Is t Zt t B tB IB sIB I Zts s% IsI - 8s Ns s8s t s8ABR {sRBR stR{Z t Zts R jjs I t Z Bt R et j js B I W$% t Zts R jjs I R $}B js z7Td R %$R$ sIs }B js ts% 7,kI$% s js A? ZRJZ Is I js - sK ts PZ 9s JZ YsA? s s{sAsIB {Bt js %$Is I jBR $}Zjst R I Zts 8$R$? Bt st $B *${Ys PZ 9s
eR}s{$B d {BtR $ Zk Zts $t$ ZsjsAj sj ? s I B R {$ t ? h{BRU I RI js {BtPZR$? Bt t R jjsR k sR B$I R }sRstIB }B j ZRB I jBR }s R {R wZt$IsI R I I$R st{$s t sR BtB8? s JZ$%sT ;
j t R s n 1E sK tBR jZ9 B , ;E
8B%$8$ t B I js NZts t RZ %$s` R$t ht s jBR {Btht R I j R}s{$B
Bt I j } B}$B d(@ ,8D {B8B Zt$IsI R I % jB{$IsI YsR s js I R{ $}{$?
© Los autores, 2001; © Edicions UPC, 2001.
M(
* $t Bt s e$tR $t
RZj s R sj B st {B $I$stB {B8B js s% IsIU jsR $ ? st${sR PZ 9sR I 8s sN } R t R t jsR } B-$8$IsI R I Zts R jjs I t Z Bt R } B%B{st Zt sI$ t I s% IsI st j %sIB JZ ? RZR P { BR RZj st I %sR sIB R }s s j {Z }B YZ8stB eR 8}$ 9s s R $ s R RB8 $IB s I$R $t BR sIBR I s s{{$? Bt t PZt{$? Bt I js I$R st{$s s js R jjs eR Y {YB $ t jZ s s8A$? t t js RZ} h{$ R IBtI Zt R YZ8stB sj {s8$ts }BI ? s tB s {? B8B RZR }$ R RBt s s? IBR {Bt 8skB $t tR$IsI JZ RZ {sA 9s 7$t 8As B I A$IB sj 8BI R B %sjB I js s% IsI R j P { B RZj s {B8}j s8 t $ts} {$sAj et
<Z %B I * s ? Bt R ts s js BI$R s I js ts% R I -}jB s{$? Bt 7st FB t B ? A$ s $8}BR$Aj {$ {ZtR st{$s
sj I IB I js R jjs I t Z Bt R I R{ZA$ s t js {BtR js{$? Bt I j * s ? Bt NsR {BtI${$Bt R - 8sR I s% IsI k {s8}B 8s t? ${B Ys{ t I ? R Zt 8ZtIB R$IB RZR $ Z$IsR }B {B8}j `sR s{{$Bt R {Bt t Z Bt R YsA$ st jBR JZ tB $8}$I s RZ sZ B I Rs Bjjs Zts {Z $BRs A$BjB ? s IBtI jsR s{{$Bt R JZ? 8${sR Yst
{Y js ZtBR R R s8 AB$I R I R? BjB ( x 88 I sj Z s k {Bt PBA$s s jsR sj Z sR <Z %B I * s ? Bt }BR Zts 8sRs
eR t R - sK tB 8ZtIB IBtI
Y I BR I j BtB B{Z}sIB }B jBR 8 R,j$t$ sR I <sj ]j 8 t t js Y$R B $s I js {$ t{$s h{{$? Bt Ns t$ 8? s ${s R jjs I t Z Bt R AsZ $9sIs {B8B I (, x{Bt t$Is t Zt I$? s8 B I R? BjB 1( ,8 jB JZ } BIZ{ Zts $t$8s $tsAj s% IsI t RZ RZ} h{$ E d( ]B8B RZj sIB jsR 8? sR j %sIsR sj{st9st jBR d( {8
(
8Bt sK tsR
I sj Z s AsRstIB $t{jZRB js -$ Zs s 8? BRP s I %s}B I Y$ B JZ R - $ tI YsR s Zts sj $ ZI I x {8 NsR - 8sR {BtI${$Bt R s8A$ t sj R I j <Z %B I * s ? Bt R {B8}j st {Bt Bt I % { R 8? sR $t tRB JZ j {s8}B Zt - sB I$ts $B {s8}B 8s t? ${B I d(@ sZRR Zt A$jj? 8s t? ${B R Ns -} I${$? Bt YZ8sts JZ %$R$ s j <Z %B I * s ? Bt 8}j s d ; sK tBR t { Z9s jsR 1 x(( =V JZ R }s st s ? R s I js q$ s V AB IB I js 8B B I PZR$? Bt tZ{j s jBR $}Zjst R -} $8 t st Zts {? B8BIs s{ j s{$? Bt I R? BjB (, (nx sj{st9stIB Zts % jB{$IsI 8? s-$8s I ( (nx { et RZ s} B-$8s{$? Bt s js R jjs I t Z Bt R Z $j$9st Zts ts% sZ-$j$s js
7st FB JZ$}sIs {Bt Zt
s sI s Bt R
Zts RP s I 8 I I$? s8 B JZ R R$ ? Zs t
B A$ s R$t{ ? ? Bt${s s ;(E ,8 RBA js RZ} h{$ I js R jjs IBtI js s s{{$? Bt s%$ s B $s $ t Zt %sjB I ;( 8$jjBt R I _s s } B s jBR R R YZ8stBR I j sI$ t I s% IsI wjBR }$ R I Zt sR BtsZ s R s ? st s ;(E nnd 8 I js RZ} h{$ 8$ t sR JZ RZ {sA 9s R s ? s R$ ZsIs s ;(E nnn 8 {Bt Zt sI$ t I s% IsI {sA 9sT}$ R I 1(1 D R Z $j$9st 8sRsR I {B8} tRs{$? Bt et js tB% js R I R{ $A j t{Z t B t B ? A$ s t js
s sI s Bt R k Zts
8$t? ZR{Zjs ts% {Y js I ; {8 I I$? s8 B IB sIs I Zt 8 {st$R8B I } B}ZjR$? Bt I ? {t${s I R{BtB{$Is JZ j } 8$ R{s}s I j P? B sA s9B s%$ s B $B I js R jjs wJZ } R t s Zts % jB{$IsI I R{s} t RZ RZ} h{$ I ddx3((( ,8\R Zt ;(0 I js % jB{$IsI I js jZ9D
NsR PZ 9sR I 8s s RBt I A$IsR s js I$P t s s{{$? Bt s%$ s B $s JZ Zt {Z }B ` { RBA }s R I B B et j {sRB I jsR 8s sR B{ ? st${sR R R ? R sR R I A t s JZ js PZ 9s ` {$Is }B js s% IsI jZts t j - 8B I js q$ s 8? sR } ? B-$8B s js NZts R 8skB JZ js ` {$Is t j PBtIB B{ ? st${B w8? sR sj `sIB I js NZtsD *${YB P { B } BIZ{ Zt sAB8As8$ t B I js RZ} h{$ B{ ? st${s t I$ {{$? Bt s js NZts ej P { B t j }BjB B}Z R B I js q$ s IBtI R ` { Zts 8skB s s{{$? Bt RBA j PBtIB B{ ? st${B w8? sR { {stB s js NZts JZ js RZ} h{$ I j B{? stBD R 8st$h R s 8 I$st Zt sAB8As8$ t B I j B{? stB t R t $IB {Bt s $B =ts tB sAj - s}Bjs{$? Bt I jBR P { BR I jsR 8s sR s%$ s B $sR }Z I t{Bt s R t js tB% js s s R $%sj >7Z88 q$I d (H I ]Ys j R 7Y ^ jI
N
© Los autores, 2001; © Edicions UPC, 2001.
1 =ts BI$R s t j R}s{$BU I j et } $R sj <sj{? Bt $j ts $B
Md
=tB I jBR sR} { BR R t{$sj R t j jst9s8$ t B I Zts ts% sI${s t j 8 {st$R8B I $8T }ZjR$? Bt JZ } B}B {$Bts s js ts% js % jB{$IsI I R{s} sR Zts PsR I s{ j s{$? Bt Vj $ Zsj JZ t jBR } $8 BR I? sR I js s%$s{$? Bt js sR Bt? sZ ${s s8A$? t Ys t$IB JZ Ys{ P t s s{ $ ZI R { ? ${sR k ${ t R V G ${, Bt Zt I$%Zj sIB I js {$ t{$s R{ $A? s t d 1E Zt s ? {ZjB JZ V YZ ] ]js , tB Ys IZIsIB t {sj$h{s {B8B BA s 8s R sU "eR s $I s I I$R}s s Zt } Bk { $j s js NZts R Zt ` 8}jB I js sARZ Is s8}j$ ZI s js JZ js 8? sR - 8sIs k %${$BRs R} {$sj$9s{$? Bt }Z I s sR s s jBR {$ t ? h{BR JZ sAs`st t {B8}s $8 t BR RT st{BR _ 8? st8 Zt -s8 t { ? ${B I j } Bk { BU }s s JZ Zt } Bk { $j R{s} {B8}j sT s ? 8${s I Zt 8 t I js s% IsI R t { R$ s Zts % jB{$IsI I dd 1 ,8 R Ns t ? s8B s R s % jB{$IsI R I dx dM( {sjB ? sR Ns t ? s I tZ R B -}jBR$%B 8? sR %$Bj t B ujs t$ B j${ $tsu R $tP $B s jsR d x(( {sjB ? sR }B s8B ]BtR {Z t 8 t sZtJZ j -}jBT R$%B tB Z%$ s tsIs }s s stR}B s R? BjB {Bt s ? s {Bt js I? {$8s }s I js t ? s JZ Ys{ Psj s }s s R{s}s I js q$ s et {BtR {Z t{$s j } Bk { B RZj s A? sR${s8 t $8}BR$Aj " qsj k {B8B $tI${s j } B}$B ]js , R - B {Bt $ t IBR B R PZtIs8 t sj R ej } $8 B Ys{ P t{$s sj }BI -}jBR$%B I js t$ B j${ $tsU -$R t 8s $sj R {Bt Zt 8skB }BI t ? ${B JZ ? R s et }s ${Zjs jsR jst9sI sR R}s{$sj R 7YZ j ZRst IBR {BY R 8 jBR I } B}ZjRB R? Bj$IB {BtR $ Z$IB }B } {jB s B I sjZ8$t$B wZt B-$Ist D k sjZ8$t$B t }Bj%B w{B8AZR $Aj D B ?-$IB I Y$ B wJZ s{ ? Zs {B8B {s sj$9sIB D k Zt }Bj? 8 B R}BtRsAj I 8stT t js 8 9{js Zt$Is _B B B jsIB tB R {$ B JZ js t$ B j${ $ts tB } 8$ s } B}ZjRs Zts ts% s js NZts sj } B}B {$Bts R? BjB Zt d(0 I js t ? s t { Rs $s }s s R{s}s I js q$ s Ns s9? Bt sI${s t js ? Bt s {Bt{ }{$? Bt I } B}B {$Bts js % jB{$IsI I R{s} s Zt BA` B t j $tR st I j jst9s8$ t B <Bk RsA 8BR JZ Zt {BY {Bt% t{$Btsj s{ j s t Zts } $8 s PsR k %s ststIB % jB{$IsI } B R$%s8 t NsR jst9sI sR R}s{$sj R sj{st9st jBR Bt {BtR st I ZtBR n JZ R 8st $ t I RI jBR dd 1(( ,8\Y wn d ,8 RD As`B Zts s{ j s{$? } $8 BR R ZtIBR I j jst9s8$ t B ej sR{ tRB YsR s j R}s{$B %s{? B R {B8}j s t M 8$tZ BR k x( R ZtIBR , b 3 , b
eR s s{ j s{$? Bt } B R$%s R I {s}$ sj $8}B st{$s }s s j A$ t R s I js $}Zjs{$? Bt et j I R} Z I Zt s%$? Bt B t j } B}$B I R}js9s8$ t B t sZ B8? B%$j -} $8 t s8BR s{ j s{$Bt R 8BI sIsR JZ B $ $tst j % R sR B tBR } BIZ{$IBR }B j Y {YB I JZ tZ R B B st$R8B tB R B sj8 t ? $IB Ns Rst {$ {Zjs }B % tsR k s $sR JZ RBt ZABR j? sR ${BR JZ R }Z I t I PB 8s VR? {ZstIB s{ j s8BR Ys{$s s $As js Rst $ tI s s{Z8Zjs R t js }s $tP $B I j {Z }B {B8B R}Z R s sj sZ8 t B I tZ R B } RB s}s t ]ZstIB js s{ j s{$? Bt R Ys{$s sAs`B js Rst R {Bt{ t s t js }s RZ} $B I j B st$R8B FZt B s R BR P { BR Ysk JZ I R s{s j I A$IB sj I R}js9s8$ t B I jBR B ? stBR $t tBR I j {Z }B JZ s 8 tZIB } B%B{s R tRs{$Bt R I Rs sIsAj R t {s8A$BR I sRst B t {Z %sR 8Zk } BtZt{$sIsR NBR R ZI$BR P { ZsIBR A? sR${s8 t $8}ZjRsIBR }B js s}s ${$? Bt I js s%$s{$? Bt I sj s % jB{$IsI k }B jBR %Z jBR R}s{$sj R Yst 8BR sIB JZ js {s}s{$IsI I R$R t{$s I Zts } RBts s Zts s{ j s{$? Bt I } tI I j %sjB I ? R s sR? {B8B I RZ IZ s{$? Bt et I$% RBR -} $8 t BR R Ys {B8} BAsIB JZ jBR }$jB BR I s%$s{$? Bt sj Rsj$ I Zt }${sIB }Z I t RZP $ R $BR P { BRU s n js IZ{{$? Bt I js } R$? Bt I js Rst t js $ts } BIZ{$Is }B j RPZ 9B RZ}j 8 t s $B JZ I A sj$9s j {B s9? Bt }s s AB8A s Zts Rst I } RB s}s t 8? sR j %sIB } B%B{s Zts j$ s }? I$Is I %$R$? Bt V E js IZ{{$? Bt I j RZ8$t$R B I B-? tB sj { A B } B%B{s js $t{BtR{$ t{$s ej j? 8$ I Bj st{$s R ? Zt jBR P? R${BR F G st k 7 tY $8 R I
© Los autores, 2001; © Edicions UPC, 2001.
M1
* $t Bt s e$tR $t
ZtsR }B{sR I { tsR I sZtJZ j B st$R8B }Z I R$R $ s{ j s{$Bt R s? Zt 8skB R I {B s IZ s{$? Bt wqsAjs 1 1D * Y {YB jBR sR BtsZ sR I j 7YZ j ZRst s` R st $T I$R K tsIBR }s s } % t$ I R8skBR k B BR P { BR IZ st js t sIs IBtI R Ysjjst s8A$? t RB8 $IBR s Zt sZ8 t B I js PZ 9s I js s% IsI eR BR s` R {B8} $8 t jBR 8ZRjBR k jsR }st B $jjsR }s s %$ s JZ R s{Z8Zj js Rst t jsR }$ tsR Ns % jB{$IsI I t sIs t js s 8? BRP s RZ j Bt 8? s-$8s I sj{st9s ZtsR 1x % { R js % jB{$IsI I j RBt$IB wM, x ,8b RD R$ tIB js I Rs{ j s{$? ZtBR d, et jsR 8$R$Bt R V}BjB jBR sR BtsZ sR }BI? st jj s s RB}B s M t j 8B8 t B I j $8}s{ B I j 8? BIZjB jZts {Bt s js s 8? BRP s s Zts % jB{$IsI {s s{ ? R ${s I ZtBR nM3((( ,8\Y
I$B sR{ tRB U
V{ j s{$? Bt w D (, n 1, x (, 1x (, ( 1( d(( (, x 1( d(( d( dx M nn n ;
*Z s{$? Bt wRD
j? 8$ I {BtPB sA$j$IsI }s sIs I 8 t{$s
sZ B8? B%$jU s%$? BtU Rsj BU
}s sIs {BtPB sAj j? 8$ Bj sAj {Bj$R$? Bt w{Bt }BR$Aj RZ} %$% t{$sD I R} Z s $9s` {Bt {YBJZ k {{$? Bt I j sR$ t B sA Z s I j }s s{s? IsR s $9s` t }s s{s? IsR
x M n (, d d( 1( (, 1x (, 1 (, x (, d (, 1
qsAjs 1 1 V{ j s{$Bt R ? }${sR k RZ IZ s{$? Bt wsIs} sIB I 3? R${s F G st k 7 tY $8 d M D =ts I jsR {Bt{jZR$Bt R $8}B st R JZ R I $%st I j P { B I js s{ j s{$? Bt t j {Z }B YZ8stB R js t { R$IsI I %$ s PsR R I s{ j s{$? Bt j %sIsR t Zt jst9s8$ t B $}ZjsIB _B {BtR$ Z$ t Ysk JZ {B8Zt${s % jB{$IsI s js ts% I PB 8s } B R$%s s I$P t{$s I js $I s s}Zt sIs }B ${, Bt eRB tBR } 8$ -}jB s ZtB I jBR s Z8 t BR 8? sR {BtB{$IBRU j 8 {st$R8B I {sK tB ?tT{BY $I sIB }B z t t RZ tB% js * js q$ s s js NZts et js tB% js I z t R {BtR Zk Zt $ st R{B {sK tB ?t % ${sj j ]BjZ8A$sI I n(( 8 I jBt $ ZI z t t$ tIB t {BtR$I s{$? Bt jsR }? I$IsR I t ? s I A$IsR sj B9s8$ t B s 8BRP? ${B I 8$ts JZ js % jB{$IsI I Rsj$Is B ?} $8s I js ts% sj sRB8s }B j - 8B I j {sK tB ?t R I ZtBR dE ,8b R wsj B RZ} $B s js % jB{$IsI I R{s} dd, 1 ,8b RD i RZj s R t{$jjB R $8s js s{ j s{$? Bt JZ -} $8 t st jBR 8$ 8A BR I js $}Zjs{$? Bt 7$ RZ}Bt 8BR JZ j } Bk { $j }s I j }BRB k R s{ j s I PB 8s {BtR st s jB js B I jBR n(( 8 I {sK tB ?t YsR s sj{st9s Bt I g;n3x(( j - 8B I Rsj$Is {Bt Zts % jB{$IsI I dE ,8b R R BA $ t Zts s{ j s{$? _ R s JZ j {Z }B YZ8stB }Z I RB}B s s{ j s{$Bt R - 8sR I A % IZ s{$? Bt ;n3x(( IZ{$ ? st 8Zk }BR$Aj 8 t js $}Zjs{$? Bt s Zts }s}$jjs Rst Z$tBj t s wB }s sP sR stIB s 7 }Y t s- t NsR ts% R I j $ 8}B >qY q$8 7Y$}R d xxH s "8 8 jsIs I P Rs"D =t $t t B I 8 `B s I j {sK tB ?t I z t jB } B}B {$Bts ]Y $R B}Y _ $ R t RZ tB% js Ns
© Los autores, 2001; © Edicions UPC, 2001.
1 =ts BI$R s t j R}s{$BU I j et } $R sj <sj{? Bt $j ts $B
Mn
3$ 1 ; wy9JZ$ IsD z$R s $I sj I j {sK t? Bt I F q sR Bt $I sIB }s s } B}ZjRs s jBR } $8 BR YB8A R s js Bt B $ $tsj I js tB% js * js NZts w* {YsD ej } Bk { $j s RZ jj sIs s 7 Bt :R <$jj p sAsIBR I js I${$? q$ s s js NZts >* js q r s js NZt dMExH I j } {Z RB P st{? R FZj R z t
8? sJZ$ts R}s{$sj
>qY 7}s{ s{Y$t d EHU ZA${s RZ {sK t? Bt t js RZ} h{$ I s IBtI js
% jB{$IsI I R{s} R sj B $tP $B s js R w]ZsI B 1 dD s8}j$stIB js jBt $ ZI I j {sK tB ?t s d, x ,8 _ R sj $t t B I IZ{$ js s{ j s{$? Bt IZ st j jst9s8$ t B ? R s sj{st9s ? s ZtBR MMx _s s BA t Zt %sjB 8? sR {BtPB sAj d I A ? s8BR {BtR Z$ Zt ZAB MMx % { R 8? sR js B I Zts jBt $ ZI I ZtBR gd n((,8 w{sR$ js 8$ sI I j sI$B I j }jst s s U g j } $8 {YZ}sT{YZ}R $ st I j 7$R 8s 7Bjs D
ej %$s` JZ jj %s s q$t ? t s js NZts I js 8stB I j I$AZ`st < ? tB R ? s s8}B{B - t B I sj ZtBR {Z $BRBR }jst s8$ t BR qsj k {B8B 8Z R st jsR 1 %$K t sR I js h Z s 1 x jBR
? {t${BR I j ] t B I yt% R $ s{$Bt R V ? B8${sR I 7A [ BI` t 7$jIs%$s $tPB 8st s q$t ? t k RZR s{B8}sK tst R JZ js ts% JZ jBR {BtIZ{ s js NZts Ys sj{st9sIB Zts % jB{$IsI I dn ,8b R }B jB JZ "ks tB R t{Z t st RB8 $IBR s js s% IsI R " eR {B8 t s $B R sARBjZ s8 t PsjRBU js s% IsI sZtJZ }Z I {BtR$I s R I R} {$sAj s Zts I$R st{$s
s Zt %sjB I d, x 8bR D RZh{$ t I js q$ s wI Y {YB s d(3((( ,8 I RZ RZ} h{$ $ t BIs%? tB I Rs}s { 8$R $BRs8 t et R R t $IB sj{st9s js % jB{$IsI I R{s} tB R$ t$h{s
j$A s R I js PZ 9s I js s% IsI R$tB
% t{
RZ P { B _B B B jsIB js % jB{$IsI I R{s}
s d(3((( ,8 I js RZ} h{$ R R IZ{ s Zt %sjB I ,8b R }B jB JZ jBR dn ,8b R I
© Los autores, 2001; © Edicions UPC, 2001.
M;
* $t Bt s e$tR $t
]ZsI B 1 1 N k R I W b Bt ]BtR %s{$? Bt I j 8B8 t B NsR j k R I W b Bt RBt js{$Bt R 8}? ${sR JZ {Bth Z st js AsR I js 8 {? st${s j A R {j? sR${s 3B 8ZjsIsR }B j P? R${B A $ ? st${B yRss{ W b Bt wdE;1Td 1 D t RZR {? _Y$jBRB}Y$s Ws Z sj$R _ $t{$}$s s Y 8s ${s >dEMEH }Z I t tZt{$s R I js PB 8s R$ Z$ t U d et sZR t{$s I PZ 9sR - tsR t sR Zt {Z }B } 8st { t RZ R sIB $t${$sj I }BRB B I 8B%$8$ t B { $j? t B {Bt % jB{$IsI {BtR st 1 ej P { B I Zts PZ 9s - $B t s RBA Zt {Z }B I 8sRs {BtR st R 8st$T h R s t PB 8s I Zts s{ j s{$? Bt t js 8$R8s I$ {{$? Bt JZ js PZ 9s s}j${sIs k 8? BIZjB } B}B {$Btsj s js 8s t$ ZI I js PZ 9s $t% Rs8 t } B}B {$Btsj s js 8sRs I j {Z }BU 3Z 9s t s ) 8sRs s{ j s{$? Bt n NsR PZ 9sR R } R t st R$ 8} }B }s `sR VR? R$ Zt {Z }B \ ` { Zts PZ 9s us{{$? Btu RBA B B {Z }B ? R ` { s RZ % 9 Zts PZ 9s RBA j } $8 B I $ Zsj 8s t$ ZI } B R t $IB B}Z R B u s{{$? Btu =t {Bt{ } B j$ sIB s js R ZtIs j k I W b Bt R j I tB8$tsIB 8B8 t B j$t sj B {st $IsI I 8B%$8$ t B I ht$IB {B8B j } BIZ{ B t js 8sRs I Zt {Z }B k RZ % T jB{$IsI et sZR t{$s I PZ 9sR - $B R j 8B8 t B j$t sj R {BtR %s eR } $t{$}$B I {BtR %s{$? Bt } 8$ -}j${s }B ` 8}jB js I$t? s8${s I jBR {BY RU js -}ZjR$? Bt I jBR sR R } B{ I t R I js {B8AZR $? Bt $8}ZjRs js ts% t R t $IB {Bt s $B
ej sR{ tRB I j stRAB IsIB R}s{$sj ]Ysjj t 8s` R ZBRs 8Z R s I js {BtR %s{$? Bt I js {st $IsI I 8B%$8$ t B
© Los autores, 2001; © Edicions UPC, 2001.
1 =ts BI$R s t j R}s{$BU I j et } $R sj <sj{? Bt $j ts $B
Mx
3$ 1 x =ts I jsR } $8 sR $8? s t R I js q$ s %$R s I RI j R}s{$B wV $9s` t js NZts >!t s 8s {Y? D RZ js NZt d x;H I < ? JZ Ys{ 8 t{$? Bt < ? tB $ t t t$t ? Zt R t $IB 5_BI ? s sj ? Zt I? s j %s R Zts ts% {Bt s js PZ 9s I js s% IsI R$t Zt 8 {st$R8B I } B}ZjR$? Bt2 ej ZRB I 8s $sj R st $ s%$ s B $BR tB Ys R$IB j Z ?t${B $t t B t R R t $IB et jBR sK tBR E( j {? j A I$ B FBYt G ]s8}A jj s{ZK tsAs t js %$R s VR BZtI$t 7{$ t{ 3${ $Bt j }B}Zjs } B}ZjRB * st Zt I$R}BR$ $%B sZ B$8}ZjRsAj R$t } B}ZjR$? Bt sj R $jB I jBR $8}ZjRB R R$t $t {$s I e e :*B{: 78$ Y =ts P t{$s {$ t RBA ts% R R$t $8}ZjR$? Bt js } B}B {$Bts V YZ ] ]js , t ]$ s {Bt is8s IBtI sj {Bt 8}js js }s $Is I js sR Bts% I jBR p stI R 7 K tB R R sh 8sU "sjj? s %s js { s j k I W b Bt" * Y {YB jsR j k R I W b Bt w]ZsI B 1 1D JZ I R{ $A t jsR {sZRsR JZ } BIZ{ t j 8B%$8$ t B $8}$I t JZ Zt {Z }B sAstIBt j }BRB t sZR t{$s I PZ 9sR - $B R t sR ej 8 {st$R8B ZRsIB t js } B}ZjR$? Bt I Zts ts% R}s{$sj R AsRs t js -}ZjR$? Bt s st % jB{$IsI I jBR sR R t sIBR t js $ t${$? Bt I j {B8AZR $Aj 7Z k {{$? Bt t Zts I 8$tsIs I$ {{$? Bt $8}ZjRs js ts% t R t $IB {Bt s $B * PB 8s st? sjB s Zt }s $tsIB t }BRB RBA Zts }$R s I Y$ jB t sZR t{$s I BIB B9s8$ t B {Bt j RZ jB }BI ? s jst9s BA` BR wRZ B}s }B ` 8}jBD }s s $8}ZjRs R t Zts I 8$tsIs I$ {{$? Bt WB }BI 8BR {Bt{jZ$ R s}s sIB I I${sIB sj st? sj$R$R I jBR I$% RBR 8 {st$R8BR I } B}ZjR$? Bt R$t 8 t{$Bts jBR $ ? Bt${BR 8? BIBR } B}Z R BR }s s sj{st9s js NZts {Bt jBR JZ ]k stB I s{ } tI sj `s sj %$j * pY${Y I js {sRs I RZ s8sIs iBRstts t js tB% js I eI8BtI iBR stI RBA R } RBts` * `s8BR sj j { B js Y$js st s s I stsj$9s js %$sA$j$IsI I R BR 8? BIBR k j st$8s8BR s } BAs jBR JZ {BtR$I Ps{ $Aj R
© Los autores, 2001; © Edicions UPC, 2001.
@
* $t Bt s e$tR $t
` 8}jB qs BB$t j }jst sT{Zts I NZ, 7,kbsj, VjI sst YB s I js } $t{ Rs N $s B js } B}$s eR jjs I js Z Zt }jst B$I s $h{$sj k YZ {B I RI IBtI B} s j R$t$ R B y8} $B qs8}B{B t j 8B B 8ZtIB Y jsIB I <B Y t ej y8} $B {Bt ss s{s B t j 8$R $BRB *s BAsY R$I t{$s I j 8s R B F I$ OBIs R s} {$s j 8? sR 8? t$8B {s8A$B I s% IsI WB R BAR %st R? t B8sR I $t s%$I 9 s AB IB I jBR 8$t? ZR{ZjBR {s9sR qye $8} T Bt $j ts $BD eR I$P? {$j $sj R t$ t jBR {s9sR I js Vj$st9s i A jI w}B tB {$ s j <sj{? RZ}Bt JZ t BIs Rs 8$ ? sIs I ts% R jZtsR k }jst sR {Bt 8sRsR k I$8 tR$Bt R I$R $t sR js s% IsI } R t Zt 8$R8B %sjB Zt$% Rsj WZ R s -} $ t{$s {B $I$sts tBR Ys s{BR Z8A sIB s {Bt%$%$ {Bt j Y {YB I JZ js q$ s s s jBR BA` BR sZtJZ tBR RB } tI } tRs JZ BIBR jBR BA` BR R s s t s RZ % 9 t R? wIBR } RBtsR }Z I t s8A$? t s s R 8? Z Zs8 t sZtJZ jsR PZ 9sR t `Z B RZ j t R I B s ts Z sj 9s D N `BR I js q$ s R P { B }Z I R }B t{$sj8 t $8}B st sZtJZ tB Ysk JZ Bj%$Is JZ R? BjB stI R 8sRsR }Z I t } B}B {$Bts Zts s s{{$? Bt s%$ s B $s tBT js 8s $s JZ {BtR $ Zk Zts ts% R}s{$sj I$P? {$j8 t }BI ? s t s js RZh{$ t B $sM VR? s% IsI }s s s s BA` BR I PB 8s s} {$sAj VZtJZ } B s? Zt R js R$ Zs{$? Bt JZ tBR A $tIs NBR } $8 BR YB8A R t js NZts I < p G jjR B RZ sIs} s{$? Bt {$t 8s B ? sh{s Ns st RB } Rs >3$ R t $t Y BBt d E;H IBtI jBR $}Zjst R I Zts ts% RP? ${s RBt s s? IBR Ys{$s RZ { t B B8? ${B jZ s IBtI } {$Rs8 t js s% IsI R tZjsU "]B8} tI? } P { s8 t jB JZ YsA? s RZ{ I$IB } B jjB tB %$ ? B JZ R$t $ s 8$ IB eR ? sAs8BR s$RjsIBR I BIs s%$ s{$? Bt - $B k RBjs8 t R Z? s s{ ZstIB js s s{{$? Bt t jBR BA` BR JZ YsA? s t j $t $B I js RP s _B jB st B BIB jB JZ tB R sAs h`B t j { $R sj {s? s wj t sT 8 t s {sZRs I js j$ 9s JZ YsA? st sIJZ$ $IB jBR {Z }BR {Bt t$IBR t js RP sD Ys{$s j { t B I s% IsI I tZ R B } JZ K tB 8ZtIB JZ }s {? s Ysjjs R t j { t B B8? ${B I js RP s } B sj B 8? sR { {s I 8? JZ I ]s%B }B JZ j } RB I 8$ {Z }B s RZ} $B sj RZkB" =ts }BR$Aj -{ }{$? Bt s js t s{$? Bt I s% IsI t Zts ts% R js } R t sIs t j hj8 ytI } tI t{ *sk >d EH IBtI jsR $ st R{sR I$8 tR$Bt R I js ts% tBI $9s xx( ,8 I I$? s8 B k RZ tB 8 8sRs d\n I js 8sRs I js NZts RBt RZh{$ t R }s s t s Zts tB sAj s% IsI et R {sRB j } BAj 8s sI${s t js I tR$IsI JZ I A ? s t j 8s $sj Z $j$9sIB t js {BtR Z{{$? Bt I R 8 `st R Z{ Z s 8Zk }B t{$8s I js I {ZsjJZ$ 8s $sj R {BtB{$IB VZtJZ JZ$9? sR tB R s ? R j {sRB t RZ I$R st 8ZtIB ts sj 7$t 8As B Zts ts% tBI $9s st $ st R{s tB }BI ? s R$R $ jBR %$Bj t BR P { BR I 8s s I js s% IsI R k 8$ts ? s }B P s 8 t s R yt{jZRB jsR I { tsR I ts% R sZ-$j$s R I 1x ,8 I I$? s8 B RZj st I 8sR$sIB stI R }s s R$R $ RsR PZ 9sR * Y {YB tB R {sRZsj JZ jBR }jst sR I j 7$R 8s 7Bjs } R t t Rs ? j$ R ts Z sj R ZA${sIBR 8? sR sjj? s I jsR 9BtsR I $t R sA$j$IsI }B 8s sR =ts -{ }{$? Bt js {BtR $ Zk t jBR st$jjBR I 7s Z tB JZ I Y {YB R ? st {BtR $ Z$IBR }B Zt {Bt`Zt B I }s ? {ZjsR I 8 tB s8sK tB +Z$9? sR YZA$ s R$IB Zt htsj 8? sR I$ tB }s s js } j? {Zjs 7$t IZIs tB sAj 8 t 8? sR B $ $tsj JZ j ZRB I Zt %$ ZR $tPB 8? s ${B }s s s{sAs {Bt Zts $t%sR$? Bt sj$ t? ts
Ns PZ 9s I s s{{$? Bt s%$ s B $s R } B}B {$Btsj sj } BIZ{ B I jsR 8sRsR JZ $t s{{$Btst $t% Rs8 t } B}B {$Btsj sj {ZsI sIB I js I$R st{$s JZ jsR R }s s {B8B $jZR s js j k I js s%$ s{$? Bt Zt$% Rsj tZt{$sIs t dEME }B yRss{ W b Bt
M
© Los autores, 2001; © Edicions UPC, 2001.
1 =ts BI$R s t j R}s{$BU I j et } $R sj <sj{? Bt $j ts $B
@ @
3$ 1 d1 wV $AsD 3B B s8s I j hj8 Ns st RB } Rs >3$ R t $t Y BBt d E;H IBtI R s} {$s js B8 ? s {sR$ RP? ${s I js ts% wVAs`BD Ns = 7 7 ]k tZR I js } j? {Zjs ej sA$R8B t B >qY js{, <Bj s8${s 8? sR s{B I {Bt jsR {s s{ ? R ${sR I j %Z jB R}s{$sj d H Zts R Z{ Z s }B{B s BI$t?
© Los autores, 2001; © Edicions UPC, 2001.
@
* $t Bt s e$tR $t
3$ 1 dn =ts %$R$? Bt s}B{sj? } ${sU jsR $8}BR$Aj R ts% R sZ-$j$s R I 1x ,8 I I$? s8 B {ZA $ tIB j {$ jB I stYs st WZ R BR 8? sR {? BtI$ BR 8B R R Ys{ t sj$IsI st js 8s t$ ZI I js $t%sR$? Bt et js PB B sP? s $tP $B js eR s Zs I js N$A sI ks{ I RI$AZ`sIs s jBR }$ R I B s I jsR ts% R * js } j? {Zjs ytI } tI t{ *sk >ytI } tI t{ *sk d EH
© Los autores, 2001; © Edicions UPC, 2001.
1 =ts BI$R s t j R}s{$BU I j et } $R sj <sj{? Bt $j ts $B
d(n
1 x
7 AZR{s AB Bt R }s s sR{ tRB R}s{$sj
=tB I jBR } BAj 8sR PZtIs8 t sj R I js {tBjB ? s t 8s $s R}s{$sj R RZ {Bt $AZ{$? Bt s js }BjZ{$? Bt s{? ZR ${s k s8A$ t sj sR? {B8B j sj B sR B t ? ${B t j jst9s8$ t B I {BY R VZtJZ j stRAB IsIB R}s{$sj Ys RZ}Z R B Zts 8 `B s {BtR$I sAj sj Z $j$9s R st }s I RZR {B8}Bt t R jBR {BR R I jsR 8$R$Bt R R}s{$sj R R$ Z t R$ tIB j %sIBR 7 Yst $t t sIB $I s 8? BIBR sj ts $%BR I }Z R s t B ? A$ s {B8B js jjs8sIs B B A$ sj {BtBT {$Is s8A$? t {B8B s hB R}s{$sj PZt${Zjs {? BR8${B sjjB I YsA${YZ js B 8? sR {B8? Zt8 t sR{ tRB R}s{$sj Ns {Bt{ }{$? Bt I j sR{ tRB R}s{$sj R 8Bt s s jBR sK tBR E( t }j ts h A I js {s s R}s{$sj Zts $I s I Rs BjjsIs $tI } tI$ t 8 t }B j P? R${B OZ $ W V RZT stB% t d E( JZ$ t RAB9? B j I$R K tB I Zt PZt${Zjs {? BR8${B {s}s9 I j %s d1 ((( Bt jsIsR I$s $sR YsR s js B ? A$ s R$t{ ? Bt${s k }B FBYt * yRss{R k {BjsAB sIB R JZ$ t R t d EE }ZAj$T {s Bt Zt s ? {ZjB t js %$R s 7{$ t{ As`B j ? ZjB "_ BjBt s{$? Bt I j Rs ? j$ t Zt % IsI B s hB R}s{$sj" O {B8B 8? t$8B }s { YsA R $t% t sIB t IBR B{sR$Bt RU t js } $8 s V i ]Bjjs k F G 3jBb }ZAj${sAst t d E Zt s ? {ZjB $ ZjsIB "=t Rs ? j$ I 1; YB sR j$ I s sj $ ZI w js $%s8 t D As`s" IBtI stsj$9sAst js }BR$A$j$IsI I RZR} tI Zt Rs ? {B8Zt${s{$Bt R R$t{ ? Bt${B 8Zk }B I As`B I RZ sj $ ZI ts Z sj I nE ((( ,8 } R s tB jj s s {Bt{ s js }BR$A$j$IsI I I R{ tRB I j {sAj YsR s js RZ} h{$ R et R } $ 8A I d x s}s {? s s8A$? t "Ns B B A$ sj Zt jst9sIB I ts% R R}s{$sj R JZ Z $j$9s ? s js t ? s B s B $s I js q$ s" I F B8 _ s RBt !
7$ js }s t$IsI {$ t ? h{s I js $I s R I$R{Z $Is RZ } $8 s s}s ${$? Bt t Zts tB% js I {$ t{$s h{{$? Bt Ys j %st sIB }Bj%s Is et d % ? s js jZ9 NsR PZ t R I j }s s? RB >qY 3BZt s$tR BP _s sI$R d H I V YZ ] ]js , et j 8$R8B sK tB s}s {? s {sR$ R$8Zj ? st s8 t Ns js sK ts t jBR 8ZtIBR >qY G A b t GB jIR d H I j s8A$? t P? R${B A $ ? st${B ]Ys j R 7Y ^ jI et js } $8 s tB% js zstt %s B st Zt Ps8BRB $t t$ B JZ s{sAsAs I {BtR Z$ j }Z t 8? sR js B I j 8ZtIB R tP sR{s t j s}sR$Btst } Bk { B I j sR{ tRB R}s{$sj I$R K tstIB Zts 8? sJZ$ts js s sK ts JZ }Z I ` hA s I {s ABtB { $R sj$ts et js R ZtIs iBA j$t Zt Ps8BRB $t t$ B JZ s{sAsAs I {BtR Z$ ZtB I jBR }Z t R 8? sR js BR I j 8ZtIB R tP sR{s t j s}sR$Btst } Bk { B I j sR{ tRB R}s{$sj I$R K tstIB Zts 8? sJZ$ts js s sK ts JZ }Z I ` hA s I R$j${$B { $R sj$ts 5]B$t{$I t{$s2 et {s s sA$ s sj ABj ? t I js 73GV sRB{$s{$? Bt I R{ $ B R I {$ t{$s h{{$? Bt I jBR eR sIBR =t$IBR V YZ ] ]js , s $h{s RZ RB } Rs I JZ sj {B$t{$I t{$s tB Ysks t$IB jZ s st $B 8 t {ZstIB j {Bt{ } B B $ $tsj YsA? s R$IB RZ $IB {sR$ 1( sK tBR st R ej $t B st I R$ ]js , B 7Y ^ jI {B}$s Bt RZ $I s I j B B } 8st { BIs%? s R$t Zts R}Z R s {js s ej 8 {st$R8B A? sR${B I j sR{ tRB R}s{$sj }Z I t{Bt s R t {ZsjJZ$ s I s8AsR tB% jsR et NsR PZ t R I j }s s? RB zstt %s B st Zt $t t$ B I j R$ jB yy }jst s {BtR Z$ Zt sR{ tRB B A$ sj Zts B JZ {Bt { Zt }Zt B I j {ZsIB R {Bt Zts AsR B R s{$Bts $s s nE ((( ,8 I sj Z s Ns R s{$? Bt R R 8}js9s t js 8Bt sK ts Rs sIs 7 $ stIs I js h{ ${$s $Rjs I qs} BAst V Zts sj $ ZI I 1x ((( ,8 R ZA${s js R s{$? Bt $t 8 I$s {Bt{ A$Is {B8B 9Bts I I R{stRB ej sR{ tRB {BtR s I x }$RBR {$ {Zjs R I Zts sj Z s I n 8 k Zt I$? s8 B I M 8 k }s YsR s j Rs ? j$ st{js t Zt $ 8}B I YB sR Z $j$9stIB }s s jjB 1 ZABR I sR{ tRB k 1 I I R{ tRB Ns R Z{ Z s R {BtR Zk I RI js B ? A$ s BR$t{ ? Bt${s k 8st $ t RZ { t B I 8sRsR t js }BR${$? Bt I js B ? A$ s w t JZ$j$A $BD V stI R sR BR j } Bk { B !
© Los autores, 2001; © Edicions UPC, 2001.
d(;
* $t Bt s e$tR $t
3$ 1 d; =ts %s $st I j sR{ tRB R}s{$sj {Bt{ A$IB }B j $t t$ B I j R$ jB yy zstt %s B st I js tB% js NsR PZ t R I j }s s? RB >qY 3BZt s$tR BP _s sI$R d H I V YZ ] ]js ,
}s { %$sAj 7$t 8As B I A Ys{ P t s js Psj s I Zt 8s $sj JZ }Z Is R$R $ jsR $Aj R 8s sR s%$ s B $sR et js tB% js R RZ}Bt JZ s htsj R I j R$ jB R I Rs Bjjs ? st jBR Y$} hjs8 t BR 8s $sj R JZ {Z8}j t jBR JZ$R$ BR I I$R K tB FZt B s I${YB } BAj 8s ? {t${B ]js , RBR $ t JZ j st t? Z8 B I R{B8A BR R}s{$sj R t B ? A$ s sj I IB I js q$ s }BI ? st R$ t$h{s Zt s% } j$ B }B j $ R B I {Bj$R$? Bt {Bt js B _BI 8BR t{Bt s B BR ZRBR I j sR{ tRB R}s{$sj t B s I jsR tB% jsR I ]js , ]? st ${BR I js j `sts q$ s IBtI R 8}j s }s s stR}B s tB 8 R }$ 9sR I Y$ jB I RI Zt }Zt B I j {ZsIB I j }jst s qYsjsRRs YsR s js ts% R s sjjst R ZA${sIs t B ? A$ s R s{$Bts $s et js tB% js R Ys{ P t{$s s8A$? t sj } $8 sR{ tRB R}s{$sj {BtR Z$IB t js q$ s t js {Z8A I j $j$8st`s B Ns js sK ts t jBR 8ZtIBR ts s Zts Y$R B $s }s {$Is VJZ? iBA j$t {? j A {BtT R Z{ B I j }Z t qs$bst gI d;( ,8 I js B I$R K ts js s sK ts Zt I$R}BR$ $%B JZ jsAB s
8s $sR } $8sR A? sR${sR k jsR stRPB 8ts t Zt {sAj {B8}Z R B }B 8BtBhjs8 t BR I R$T j${$B R$t $t Z}{$Bt R =tB I jBR sR} { BR RB } tI t R I js tB% js R js $I s I st{js j sR{ tRB t j {ZsIB U ZRstIB Zt sR B$I s 8BIB I jsR sj B B - 8B I js B ? A$ s R$t{ ? Bt${s R {B8} tRst jsR PZ 9sR JZ $ tI t s $ s I j {sAj Ys{$s sAs`B 8 I$st Zt P { B { t ? PZ B _s s sj 8} Rs R I R $ts js tsIs I R} {$sAj {st $IsI I gd(x!((( ,8 I {sAj {Zks 8sRs sR{$ tI s ZtBR 8$j 8$jjBt R I Bt jsIsR ej Y$} hjs8 t B $8s $ts $B {Bt{ A$IB Bt }BR Zts tR$? Bt t js tB% js R$R Zts tR$? Bt I M d( W> {81 ej s{ B }B {B8}s s{$? I Z} Z s I d(x W> {81 7Z AsR st{jsIs t +Z$ B we{ZsIB D s x ,8 As`B j t$% j I j RZ jB R ? s R }Zj sIs }B Zts $t t {st $IsI I $ s ej } B}$B ]js , Ys 8st$P R sIB RZR R %sR R} { B s js %$sA$j$IsI I j } Bk { B RZ $IB t Ns js sK ts t jBR 8ZtIBRU "ej 8? BIB I j IB{ B 7Y ^ jI I st{js RZ : sjjB I YsA${YZ js: R R} jZ9tst k tB { B JZ PZt{$Bts s
© Los autores, 2001; © Edicions UPC, 2001.
1 =ts BI$R s t j R}s{$BU I j et } $R sj <sj{? Bt $j ts $B
@ N
geR Bk R Z B I JZ tB R ? s } 8$ $IB "
=ts $t Rst %s $st sj } Bk { B I t j } ? jB B I RZ tB% js
sjjB I YsA${YZ js R j RAB9sIB }B j } B}$B 7Y ^ jI sjjBR I YsA${YZ js I$t? s8${BR B
Ns js sK ts t jBR 8ZtIBR NBR } BAj 8sR I $%sIBR I js Psj s I
Zt 8s $sj st R$R t }BI ? st RB s R {Bt jBR jjs8sIBR {B8B jB I tB8$ts j sZ B
Z{B I js {Z Is Y$tI? Z {B $ tIB Zts $I s I Rs BjjsIs }B jBR
{$ t ? h{BR s %$t $tR,k iBA N 3B bs I FBYt {]s Yk k j } B}$B 7Y ^ jI t B BR ej {Bt{ } B }s I $8s $ts Zt ZAB {BtR $ Z$IB }B Zt 4Z`B {Bt $tZB I }s ? {ZjsR wAsjsR }B ` 8}jBD $8}ZjRsIsR s st % jB{$IsI I RI js RZ} h{$ R js s% IsI P ts ? st RZ s%st{ I PB 8s } B R$%s YsR s I t R jsR Ys{ I R{ tI }B Zt R ZtIB ZAB ? eR sR }B s{{$? Bt I
=ts % 9 t }BRB R
7$ R s`ZR s sI {ZsIs8 t js % jB{$IsI $t${$sj I
jsR }s ? {ZjsR k RZ I { j s{$? Bt }Z I {BtR Z$ R JZ js PZ 9s ` {$Is }B jsR AsjsR t {sIs $tR st Ys{$s s $As {B8} tR -s{ s8 t js PZ 9s ` {$Is }B js s% IsI RBA jsR AsjsR ej RZj sIB R Zt JZ$j$A $B I$t? s8${B JZ tB JZ$ j ZRB I 8s $sj R RZ} R$R t R ej $t{Bt% t$ t R BA%$BU R JZ$ Zt 4Z`B {Bt $tZB I }s ? {ZjsR jB JZ I$h{Zj s jsR s sR I }s s{$? Bt B 8st t$8$ t B O jsR } R} { $%sR $tJZ$ st RU 5JZ? RZ{ I ? s R$ R $t Z8}$ s j 4Z`B {Bt $tZB I }s ? {ZjsR k BIB j $t t$B R } {$}$ s s I RI j R}s{$B2 +Z *$BR tBR {B `s {BtP RsIBR
Ns Z ? j $8s }sjsA s RBA stI R BA sR I $t t$ ? s R}s{$sj R j } Bk { B RZ $IB }B p _Bjks,B% t RZ s ? {ZjB "=t {Bjjs R}s{$sj }s s js q$ s" wd D IBtI $8s $ts js }BR$A$j$T IsI I {BtR Z{{$? Bt I Zt st$jjB {Bt $tZB sj I IB I j }jst s - tR$? Bt ts Z sj I j } Bk { B I j sR{ tRB R}s{$sj 5WZ %s {B$t{$I t{$s2 V YZ ] ]js , sR Z s YsA {$A$IB tB ${$sR RBA R s ? {ZjB 8$ t sR }sRsAs jsR } Z AsR I $8} R$? Bt I RZ tB% js
NsR PZ t R I j
}s s? RB IBtI j $t t$ B zstt %s B st t j I j$ $B Bt? ${B I RZ Z ?j $8B js}RB I %$Is $8s $ts Zts PZ Z s {$ZIsI B A$ sj t PB 8s I Z Is B {Bjjs -s{ s8 t {B8B js {Bt{ A$Is }B _Bjks,B% k JZ R Ys{ sj$IsI sj htsj I js tB% js Vj ZtsR I R sR }B t BRsR 8Z RT sR I $t t$ ? s R}s{$sj {BtR $ Z$ ? st s{sRB js Y t{$s j sIs s jBR PZ Z BR Y I BR I js q$ s js
h 8s I j s $R s Zt 8BtZ8 t B s RZ }sRB B{sR$Btsj k P? 8 B }B R 8ZtIB s9Zj NsR ts% R I j $ 8}B I
eR }BR$Aj JZ tZ R BR I R{ tI$ t R 8ZjstIB sj } B s Bt$R s I 7 }Y t
s- sj{ t js 8$ sIs k {Bt 8}j t $t$8s $tsAj R R Z{ Z sR sR{ tRB R R}s{$sj R
B $ st R{sR RP sR I *kRBt JZ {ZA st js tB{Y $tht$ s i RZj s s $ R sIB s% t Z s sj {Bt` Z s VZtJZ sj ZtBR RZ K tBR st{ R sj R {Bt{ A$IBR }B js h{{$? Bt {BtR $ Zk t YBk t I? s Zts st $Aj sj$IsI
1 E
5iskBR2 giskBR 7$tPBt? s }s s B s Z s I jsR sjs-$sR
7B sIB j } BAj 8s I js s s{{$? Bt s%$ s B $s s{ {s R B R{s}s I Zt }jst s YBR $j t sK ts B B $}B I $ R BRU sj }BR$Aj $t%sRB B PZ $ $%B Ys{ R j? sR {sK tBt R I P tR$%BR B B } IBR I PB Bt R s{ {Yst Ns {$ t{$s h{{$? Bt Ys R$IB R} {$sj8 t } ? BI$ s t {tBjB ? s
8$j$ s Zts - s}Bjs{$? Bt I js {BR BRs wk sARZ IsD {s s I s 8s8 t BR I tZ R B 8ZtIB sj eRs {Z $BRs }Z ts }B IB s s js R} {$ YZ8sts I s 8sR {sIs % 9 8 `B R {Bt jsR JZ st$JZ$js R 8? Z Zs8 t I Zts 8st s 8? sR P { $%s R }s sj js sj I Rs BjjB {tBj? B ${B V
© Los autores, 2001; © Edicions UPC, 2001.
@ -
* $t Bt s e$tR $t
3$ 1 dx ! B tPBJZ I$s8 sj8 t B}Z R B RBA j 8s {Z t I js $t%sR$? Bt - s R U jBR $ttZ8 sAj R }js $jjBR %Bjst R I s R V s{,R > s R V s{,R d EH 7Z 8 tB s8sK tB j R } 8$ $ ? s } t s t js s 8? BRP s R {Bt Zt 8 tB $ R B I Z} Z s WB Ysk I sjj R JZ I R% j t j 8B $%B I js B s{$? Bt I jsR ts% R Ns t s{$? Bt I s% IsI BAj$ s ? s s B{Z}s jsR $Bt R js sj R I js ts% {$ {ZtR st{$s JZ R $ tB s t j hj8 et js PB B sP? s $tP $B jBR 8s {$stBR sRsj st j sR$jB IBtI R$I js R$8}? s ${s sAZ js WB $R Y B? ts $t%BjZt s $s I js R$R t{$s YZ8sts
© Los autores, 2001; © Edicions UPC, 2001.
1 =ts BI$R s t j R}s{$BU I j et } $R sj <sj{? Bt $j ts $B
d(
8 tZIB R s s{ $%$IsI R `ZR $h{s t s sR I j 8st t$8$ t B I Zt JZ$j$A $B I PZ 9sR t jsR }B t{$sR k I jsR Zj $B R s}j${s{$Bt R JZ s{sAst % $ tIB t s%st{ R {tBj? B ${BR s j {sRB I j sIs D =ts {s s I s 8s8 t BR JZ Z%B ZtB }s s js YZ8st$IsI w{B8B R ? I RZR }Zt BR s ?j $IBR t js jjs8sIs yt${$s $%s I * P tRs eR s ? ${s Rs B s Z s I jsR sjs-$sR ts{$Is t j B{sRB I js Z s P ? s Os j Y$R B $sIB I js st $ [ Z IsI NZ{$stB s $AZk s V JZ? 8 I R js I P tRs I js {$ZIsI I 7$ s{ZRs I j $8}js{sAj sR I$B B8stB wYs{$s j 1d; s ] D {Bt j ZRB I Zt R$R 8s I R} `BR Y? sA$j8 t B $ t sIBR }s s 4 `s js jZ9 RBjs RBA jBR ts%? BR t 8$ BR {BtR$ Z$ tIB $t{ tI$s js 4B s B8sts JZ R I$R}Bt? s s t s t j }Z B Ns R s I V JZ? 8 I R PZ {BtR Z$Is t d nU ( R} `BR I ZtBR d n8 PB{sj$9s Bt js jZ9 I j 7Bj RBA Zts As {s R$ ZsIs ZtBR x(8 8s sI t B Ns 8sI s I j ts%? B }$t sIs I {BjB BR{Z B 8} 9? B s s I }B{BR R ZtIBR I R}Z? R _ R s JZ jsR j k R I js 4 -$? Bt st A$ t {BtB{$IsR }B V JZ? 8 I R k } R s JZ jBR $ BR I js ? }B{s ks Z $j$9sAst RZ} h{$ R 8 ? sj${sR }Zj$IsR {B8B R} `BR tB RsA 8BR R$ R s R s Z%B jZ s sj k {B8B R I R{ $A _s { I$P? {$j {BtR Z$ js } {$R$? Bt JZ $Is {jZ stIB t R$t t ts8$ t B } %$B ! BR Y$R B $sIB R Yst s}Zt sIB {B8B $I s 8? sR }jsZR$Aj JZ V JZ? 8 I R YZA$ s I$R K tsIB k {BtR Z$IB {s s}Zj sR JZ jst9s ? st 8s $sj $t{ tI$s $B RBA js 4B s B8sts $t%sRB s NBR s B $9sIBR RBjIsIBR B8stBR }ZI$ Bt YsA { ? IB JZ R s sAs I stI R ABjsR I PZ B } B{ I t R I$ { s8 t I j 7Bj qs8A$? t V YZ ] ]js , Ys 8}j sIB R {Z RB t RZ js B =t j$ B {sRB I $tRBjs{$? BtU jBR R} { sIB R I Zt }s $IB I P? Z ABj I$R ZR sIBR {Bt js s{ Zs{$? Bt s A$ sj {Bt{ t st js sI$s{$? Bt RBjs RBA js } RBts I j s ? A$ B {Bt jsR {s Zj$tsR A $jjst R I j } B s8s IBtI R stZt{$st jsR h R sR I j }Z AjB ,
* $ Zsj PB 8s 3 st{$R s{Bt YsAjs t Ns tZ %s V j? st $Is >dE1 H I }B t R {sK tBt R -T }jBR$%BR k "PZ BR JZ s I t t j s Zs $t - $t Z$Aj R" VZtJZ R {BtR$I s s qY i $ t BP p B zy d ((T1x >d EnH js } $8 s tB% js A? j${s {Zks s{{$? Bt stR{Z t j PZ Z B w t j j `stB R$ jB D et j R$ jB y {Bt j I R}Zt s I j s%st{ {tBj? B ${B js {s s I s 8s8 t BR jj s s {Bt% $ R t Zt R $8Zjst I js $8s $ts{$? Bt et qY Vt j BP Y i %T BjZ $Bt >dM nH p B p $^ Y $8s $ts Zt 8ZtIB t Z s IBtI s%$Bt R k RZA8s $tBR %st s 8sIBR {Bt -}jBR$%BR I Zts }B t{$s R$t } { I t R FZj R z t t Vt js AstI s >3s{ sZ I s} Z dM EH } R t s Zt $t t$BRB -}jBR$%BU j PZj Z sIB IB sIB I P { B AZ8 st } $8$ $%B } { I t I j 8$R$j Z$sIB qs8A$? t < A p G jjR RAB9s js $I s I j stJZ js 8? sJZ$ts I Z s $t%Zjt sAj t NBR s{B s9sIBR R R >qY NstI y Bt{jsIR d (nH ! s tB% js I p B p $^ Y qY NB I BP NsABZ >d ddH t js JZ R I R{ $A Zts { Z t s Z s {Bt 8$R$j R s ? B8${BR k skBR I R$t sIB R R j 8BI jB I s $jj ? s s 8s8 t ? R ${s R Z$IB }B js {$ t{$s h{{$? Bt YsR s js s{ Zsj$IsI VZtJZ I js $tht$IsI I tB% jsR RBA Z sR k {Bt $ tIsR PZ Z sR R{ $ sR t R s ? }B{s I R s{s Ns Z s I j s$ >qY Gs $t Y V$ d (MH I j %$R$Bts $B G jjR }$Bt s t st ${$}s jBR P { BR I %sR sIB R I Zt AB8As I B s? B FZt B sj sZ I jsR 8? sJZ$tsR I Z s j } B}$B R} { B j { B8s t? ${B R $t%BT {sIB Zjs 8 t }B jBR R{ $ B R I j ? t B t AZR{s I 8$R $BRBR skBR JZ }Z Ist t P { BR 8? s ${BR et dM IBR sK tBR I R}Z? R I JZ NBZ$R NZ8$r }s t s s j {$t 8s ? B sPB R $t% t B k jBR {$? t I R{ZA$ BR skBR {Bt% ? st }s s Is jZ s s ZtB I jBR } $8 BR IB{Z8 t sj R {$ t ? h{BRU Zts } JZ K ts } j? {Zjs RBA Zts -} $ t{$s I s}j${s{$? Bt I jBR skBR
© Los autores, 2001; © Edicions UPC, 2001.
d(M
* $t Bt s e$tR $t
RBA ZtsR st{sR I sts sj$9sIs }B j IB{ B FBYt {yt k st js pjsR Bb _Y$jBRB}Y$T {sj 7B{$ k q sR js I 8BR s{$? Bt }B G$jY j8 iB t t wdM;xTd 1nD I jsR }B t{$sj$IsI R s j } $8 } 8$B WBA j I P? R${s I js Y$R B $s t d (dD k I jBR skBR w}B jB JZ {$A$ ? I js 8$R$? Bt I sI$s{$? Bt js }sjsA s skB t s t j $8s $ts $B }B}Zjs V}s { t skBR I js 8Z skBR I R$t sIB R skBR }s sj$9st R skBR Zj sT8sj%s jZ9 R? Bj$Is w D yt{jZRB ZtBR {Z $BRBR skBR $8s $tsIBR }B _ {k 3 G R 8st t qY Gs BP Y G$ j RR Gs% R >d 1nH ZRsIBR }B js s 8sIs A $ ? st${s t Zts Z s PZ Z s }s s Ys{ P t s js s8 ts9s I jBR skBR Zj sT sj 8st R *BR I? {sIsR I R}Z? R js { ZIs sj$IsI RZ} s ? s {Bt { { R jsR } %$R$Bt R 8? sR } R$8$R sR NsR 8$IsR AB8AsR %Bjst R sj 8stsR zT1 R 8A s Bt Zt B 8Z{YB 8? sR }sj}sAj JZ j } B%B{sIB }B js s8 ts9s I jBR $8s $ts $BR skBR Zj sT Ns s I jsR s 8sR I I R Z{{$? Bt 8sR$%s YsA? s 8} 9sIB ej t ZR$sR8B RZR{$ sIB t js ? }B{s }B j I R{ZA $8$ t B I tZ8 BRBR $}BR I sI$s{$? Bt jj %? B s 8Z{YBR {$ t ? h{BR I j$ % s -} $8 t s {Bt jBR 8$R8BR sZtJZ tB BIBR Z%$ Bt B js RZ I iB t t B {JZ j et d (n j P? R${B P st{? R i t? jBtIjB wdM; Td n(D BAR %? Zt tZ %B $}B I sI$s{$? Bt s js {Zsj I tB8$t? B skBR W {B8B YB8 ts` s js {$ZIsI I Wst{k t {Zks Zt$% R$IsI sAs`sAs jBtIB { k? B JZ YsA? s Y {YB t sj$IsI Zt I R{ZA $8$ t B } B R BR skBR R? BjB -$R ? st t RZ $8s $ts{$? Bt et d (; j P? R${B R sIBZt$I tR i G GBBI JZ R YsA? s I R}js9sIB s 3 st{$s }s s BAR %s $t R$ Z jBR -} $8 t BR I 8BR ? B JZ j P? R${B P st{? R R YsjjsAs t Zt B VZtJZ GBBI RZR s`B RZA } ${$s8 t IZ st js sj$9s{$? Bt I jBR -} $8 t BR }$ 9sR {js% g jBtIB k RZR skZIst R BAR %sAst jB 8$R8B _ R s JZ j P? R${B P st{? R R$ Z$? B { k tIB s jB js B I RZ %$Is t js sj$IsI I R BR 8$R $BRBR skBR jB {$ B R JZ js {B8Zt$IsI {$ t ? h{s jBR j ? B A$ t } Bt B sj $tB I j Bj%$IB I jBR sK tBR 1(Tn( RZ}Bt t j s8}Bj? t I jst9s8$ t B I jBR jjs8sIBR skBR I st }BI t ? ${B JZ A$ t R s }B {sjB B }B I R$t s{$? Bt {BtR $ Zk t jsR s 8sR BP tR$%sR }B -{ j t{$s WB% jsR {B8B Ns Z s I jBR 8ZtIBR >qY Gs BP Y GB jIR dM MH I < p G jjR B hj8 R {B8B Ns ]$ ? 3BZI Bk? >d 11H } %$R$Aj Y$R B $s I Zt {$ t ? h{B jB{B I$R}Z R B s IB8$ts j 8ZtIB {Bt Zt 8sj? h{B skB I R Z{ B {BtR $ Zk t %? sj$IsR - s}Bjs{$Bt R I j } j$ B }B t{$sj I Zt I$R}BR$ $%B 8B ? P B {s? IB t 8sjsR 8stBR et js 8$R8s j? t s pB j t$ 8? s ${B BAB I =j $8? s Z8 s js q$ s >qY *sk Y es Y 7 BBI 7 $jj d xdH 8Z R s j }BI I Zt skB 8B ? P B {s}s9 I I R$t s s jBR A j${BRBR R R s 8s8 t B $t{jZ$IB JZ BRst s t s {Bt s Zt 8$Rs $B % t$IB I j R}s{$B qs8A$? t ej skB I js 8Z >d 1xH ts s j tP t s8$ t B t Zt Y? B RB%$? ${B k Zts AstIs I Zhst R s{{$Bts $BR }B js }BR R$? Bt I j {$ sIB skB }s s ht R %$I t 8 t st s ? Bt${BR ej {Z RB sj {$ t ? h{B 8sj%sIB sj RsA$B jB{B JZ t{s ts j jsIB BR{Z B I js {$ t{$s R s8}j$s8 t -}jB sIB t I$% RsR tB% jsR I j } $8 {$B I j R$ jB qY isk >d n1H I eI8ZtI 7t jj qY V% t $t isk >d n(H I VZR $t 78sjj B p$} ABjB$I $t9Y t s ps $ts >d 1EH I j ZRB Vj - $ qBjR B$ {BtR $ Zk t I$% RBR ` 8}jBR sj ZRB 8s s9$t R skBR I js 8Z
NBR }Zj}
7$ Z$ tIB Zts js tB R{ $ s t js j$ s Z s I j ? t B jBR sZ B R I {$ t{$s h{{$? Bt Zs Ist Zt sABjZ B R$j t{$B R} { B s js ts Z sj 9s I sj R skBR ]s{ ? s $t }jst s $s >yt }jst s k <Zt d xEH I V YZ s t R {BtR $ Zk Zt $t t B I `ZR $h{s j P { B I jBR skBR }s sj$9st R t j } B{ RB I I R Z{{$? Bt I js s{ $j{Bj$ts Zt t Z B stR8$RB
© Los autores, 2001; © Edicions UPC, 2001.
1 =ts BI$R s t j R}s{$BU I j et } $R sj <sj{? Bt $j ts $B
@
ej P { B I %sR sIB I R sR s 8sR I I R Z{{$? Bt -{ }{$Btsj R Ys tI$IB s sZ8 t s {Bt j stR{Z RB I jBR sK tBR@ VR? t <$tIR$ Y Fs{, G$jj$s8RBt IB s s jsR ts% R R}s{$sj R BtD JZ } 8$ Zts } {$R$? Bt $tht$ s I Zt sZ B%$RB I skBR s{ ? Bt${BR w t$sj I tB8$ts{$? t j I$R}s B sR? {B8B Zt $t R} sIB sj{st{ s s%? R I js I$8 tR$? Bt 8}B sj VZtJZ R$ I s 8sR I I R Z{{$? Bt 8sR$%s R s s `Zt B s jBR P { BR R BR R? sj R I js AB8As ZjB xD jBR sZ B R I j ? t B Yst R$IB } ? BI$ BR k P st{s8 t $8s $ts $%BR t s ? B8${s w]s}? RZR {Bt{ }{$Bt R ej P st{? R e t R _ B{YBt $t BIZ{ t NBR YB8A R P t? ${BR >N R <B88 R 3 t $JZ RH jsR jjs8sIsR tZA R 8s s%$jjBRsR JZ }B{B h j R s RZ I tB8$ts{$? Bt } B%B{st jsR 8? sR sA st R 8Z s{$Bt R t jBR R R YZ8stBR IZ st Zts {Bt4s s{$? Bt 8ZtI$sj R =t st ${$}B I jsR 8$IsR Z sR A$Bj? B ${sR ! B R{ $ B P st{? R F st <BZ Bt I R{ $A Zt {B8}j ? R$8B s R tsj t ej R$ tB I j } B >N 7$ t IZ ]Y$ t d EdH {B8B j }k $Z8TnM Zt sR JZ $tR}$ s $ P tsAj R I R BR I - 8$ts sj R B I R R YZ8stBR jBR }Bjs $9sIB R I {s8}B JZ IZ{ t {$ZIsI R t sR s P s 8 t BR 8$t? ZR{ZjBR jsR % t BRsR I $- JZ sR}$ st w D {$ZIsI R k jsR I$R} Rst }B j R}s{$B {Bt% $IsR t }Bj%B $t }jst s $B B jBR } B}$BR { Z{ BR I $8}jBR$? Bt -} BR t IZ{$ Zts {$ZIsI s Zts 8sRs YZ8 st I s I s 8sR -$ ZB %BjZ8 t Vj ZtBR I jBR ` 8}jBR 8? sR {? j A R t R s w $R D {s B ? I s{{$? Bt I ht$ $%s RBt jsR 8$R $BRsR V V I js tB% js qY N $Bt BP 7}s{ >d ; H I Fs{, G$jj$s8RBt - sK tBR s Ps{ BR JZ B} st {Bt js 8 t I j s RB {B8B } {Z B k {Bt js } B}$s t ? s I j Zt$% RB {B8B {s s qY BIB 7 Z Bt Ys{ ZRB I Ns 8Z t A BRB {s8}B I t ? s {s}s9 I I$RBj% jBR `$IBR %$%BR k s sRs }jst sR t BR t RZ js B ej Z ?j $8B {Z RB >qY $R tB * P tR H VZtJZ I${YBR P { BR }s { t }sj$I { st jsR }B t{$sj$IsI R I j I$R Z} B Z $j$9sIB }B eI8BtI <s8$j Bt t NBR k R I jsR R jjsR >qY 7 s $t R d ; H I$sA? Bj${s { s{$? Bt JZ st$JZ$js js } B}$s R Z{ Z s I j R}s{$B k }Z I jj s s I R R sA$j$9s BIs js psjs-$s WB 8Z{YB 8? sR I jB JZ RBt {s}s{ R jsR s 8sR tZ{j s R { jBRs8 t sj8s{ tsIsR }B js YZ8st$IsI WB }BI 8BR {Bt{jZ$ R s sj ? s I YB B R R$t Zts 8$ sIs s jsR }Zt9st R { ? ${sR I sj ZtBR sZ B R I j ? t B JZ $t{$ st s 4 -$Bts RBA jB sARZ IB I js Z s *st$ j psjBZk tP t s t 3$ Y $t 7}$ $ s Zts j $? Bt YZ8sts {Bt Zts - sK ts s9s I R R R}$ $ Zsj R $t{B }? B BR JZ YsA$ st Zt 8B B }jst s 7$t B s }BR$A$j$IsI }s s j {B8As js YZ8st$IsI sIs I %BjZt s $BR JZ B} st }B { s j ]Z }B _ w_BR B 8D {B8}Z R B }B Zts 8$ ? RZ${$Is R k {B8As $ sj sI% Rs $B {Bt RZR } B}$BR R}? $ ZR t j 8$R8B }jstB JZ YsA$ s j t 8$ B g_ B s JZ? } {$B VZtJZ js } js t RsR { Z t sR As sjjsR IB8$tsIsR }B j sARZ IB js {BtR $ Zk Zt js B I iBA 7Y {,j k is9s I Z BR >Gs $B is{ H et ? j Zt }s I {B8 {$st R R R s $As s Zt }jst s }BAjsIB }B s Z $IBR k P B{ R R R s 8sIBR {Bt $ttZ8 sAj R {Z{Y$jjBR 7$t 8As B js {Z $BRs PB 8s JZ I${Ys s9s 8}j s }s s t Z sj$9s sj t 8$ B {BtR$R t gRZ RZ${$I$B {Bj { $%B s js R} s JZ j sI% Rs $B {BtRZ8$IB }B js } ts k {Bt j $Aj } RB I js 8sjs {Bt{$ t{$s s{sA }B tI$ R }s s s{sAs {Bt sj 8sRs{
VZtJZ tB BIBR jBR skBR {Bt{ A$IBR t js h{{$? Bt RZj st 8B ? P BR et j hj8 _s ? R h{B -{? t ${B jst9s Zt skB $t%$R$Aj RBA _s ? R } B%B{stIB IB 8$IB >_s $R JZ$ IB d 1nH Zt {$ t ? @
j RZ K tB I {sR$ BIBR RZR YsA$ st R -{ } B jBR JZ R Ysjjst t js qB e$& j B %BjstIB t s%$? Bt
© Los autores, 2001; © Edicions UPC, 2001.
@@
* $t Bt s e$tR $t
]s8}BR I PZ 9s k R{ZIBR } B { B R Vt sj -Y$A${$? Bt I }BI ? B A? j${B js {$ t{$s h{{$? Bt Ys {Z $IB sj $t t$B }s s jZI$ skBR $8}BR$Aj R k B BR s Ps{ BR 8B ? P BR j$tIs` R I P tR$%BR R{ZIBR I t ? s k {s8}BR I PZ 9s }sRst sR? s I R 8} K ts Zt }s} j st R t{$sj {B8B jsR } B}$sR s 8sR I s sJZ ej R}s{$B JZ BI s s Zt $8? st s Zts {Bt{ t s{$? Bt I {s s j? { ${s B s Zt }jst s }B ` 8}jB R % sj sIB }B js } R t{$s I jBR 8$R8BR 7$ {BjB{s8BR Zts ABjs I Y$ B { {s I Zt $8? st R ? s s s? Is $ 8$R$Aj 8 t }B ? R ] {s I js }st sjjs I Zt j %$RB }Z I tB s R {? B8B R $9s j % jjB {B }B sj et js RZ} h{$ I js q$ s R t $8BR j $ ? Bt I js s% IsI * {$8BR t Bt{ R JZ j R}s{$B JZ BI s s {sIs ZtB I R BR BA` BR {Bt $ t Zt {s8}B I PZ 9sU 8s t? ${B j? { ${B B s%$ s B $B R} { $%s8 t ej {Bt{ } B I {s8}B PZ $t BIZ{$IB }B j P? R${B A $ ? st${B ${Ys j 3s sIsk wd dTdME D s 8 I$sIBR I j R$ jB }sRsIB k } 8$ RBj% t s j } BAj 8s JZ st B $t{B8BI? B s W b Bt k s B BR 8Z{YBR P? R${BR I Bt {? B8B }Z I t ` { R PZ 9sR t R? IBR BA` BR JZ tB R ? st t {Bt s{ B wjs jjs8sIs s{{$? s I$R st{$sD et ? 8$tBR I R {Bt{ } B js PZ 9s JZ ` { j $8? st RBA js ABjs B j P { B I js }st sjjs I j j %$RB RBA tZ R B % jjB R $t } s {B8B js $t s{{$? Bt I jBR ${B k j? { ${B R} { $%s8 t D JZ BI s s R BR BA` BR <sR s 8$R8BR {Bt j {s8}B w8s t? sJZ? js P? R${s 5_ B JZ? R t $ tI }B {s8}B I PZ 9s B R{ZIB I t ? s t js {$ t{$s h{{$? Bt2 V 8 tZIB R s s I Zt I$R}BR$ $%B %s s8 t I ht$IB P Z B I Zts {tBjB ? s 8Zk s%st9sIs {s}s9 I s$Rjs Zts {$ s $? Bt I j R}s{$B wB I j $ 8}BD I j 8ZtIB - $B Vj B sR? {B8B Zts RP s B 8Z B $t%$R$Aj } B { B eR }jst s8$ t B I $}B I P tR$%B R j JZ 8? sR sI } BR Ys t$IB t js j$ s Z s Pst ? sR ${s ]$ 8BR }B ` 8}jB js AsR I j {jst V $I R t j }jst s V s,$R w*Zt >d M;HD JZ {Z t s {Bt Zt {s8}B I PZ 9s JZ js } B I j s sJZ I RZR t 8$ BR B jBR }B t ? R$8BR R{ZIBR I t ? s JZ BI st s 8ZtIBR t BR {B8B js jZts etIB I ej B tB I j F I$ >i Z t BP Y F I$ d MnH B j }jst s sjZts I qY$R yRjstI es Y >d xxH qs8A$? t R Z $j$9st t B BR {Bt - BR {B8B t js } B {{$? Bt I Zts ts% R js wes Y % RZR Y 3jk$t 7sZ{ R >d xEH Ns Z s I jsR sjs-$sR 7 s q , ytI } tI t{ *sk D B $t{jZRB {B8B jBR {Z $BRBR R{ZIBR $tI$%$IZsj R }s s js jZ{Ys } RBtsj I *Zt et R {j? sR${B I js {$ t{$s h{{$? Bt R{ $ B }B 3 st, < A k jj %sIB sj {$t }B *s%$I Nkt{Y jBR } B s Bt$R sR Z $j$9st Aj$tIs` R } RBtsj R JZ R sAj { t Zts R} {$ I {s8}B I PZ 9s JZ Z ?t${s8 t }Z I R sR}sRsIB }B BA` BR JZ R 8Z % t j t s8 t eR Aj$tIs` I P tR$%B } B s RZR }BR IB R I AsjsR k BA` BR }Zt9st R 8$ t sR j R } 8$ R}$ s j s$ P R{B j$A 8 t =t R{ZIB } RBtsj I R $}B $ t RZ }s sj j$R8B t js sj$IsIU {ZstIB Zt BA` B 8 ? sj${B } t s t Zts $? Bt I {s8}B 8s t? ${B $t tRB s}s { t t sJZ j {B $ t R j? { ${sR $tIZ{$IsR I tB8$tsIsR {B $ t R I 3BZ{sZj Ns } R t{$s I R sR {B $ t R $ t Zt P { B RBA j 8B%$8$ t B I j BA` B JZ R % P tsIB t 8skB 8 I$Is {Zst B 8? sR I } $Rs %s VI 8? sR } B%B{s Zt {sj t s8$ t B I j BA` B eR sR }? I$IsR t ? ${sR I A t IZ{$ R t jB }BR$Aj t sJZ jjBR I$R}BR$ $%BR {BtR $ Z$IBR }B {s8}BR 8s t? ${BR {Bt } R t{$s I }s R 8 ? sj${sR 8? B%$j R et tB% jsR {B8B ytIB{ $ts $B >ytIB{ $ts$ d (H I ]Y $R B}Y _ $ R {BtR $ Zk t Zt $t{$ B RB}B P? R${B JZ Ys{ }BR$Aj R }s s IBR $Bt R {BtP Bt sIsR I ? }B{sR I$P t R VZtJZ R$ R I$R}Bt I Zt {s8}B I PZ 9s h{$ t 5}s s JZ? R t { R$ s I Zt RB}B 8s $sj {B8B j {sR{B I js ts% 2 eR B R jB JZ } B}Bt yRss{ VR$8B%
© Los autores, 2001; © Edicions UPC, 2001.
1 =ts BI$R s t j R}s{$BU I j et } $R sj <sj{? Bt $j ts $B
@@@
t j js B
gWB I ht$ $%B
stR}s t
>WB 3$tsj d ;dH IBtI s{Bt { Zt %$s` s AB IB I Zts ts% IB sIs I Zt {s8}B I PZ 9s }B {sR{BU
"u 5VJZ? R { st jBR {s8}BR I PZ 9s2 u } Zt ? B ! jB& u get P { B 5WB Ys %$R B tZt{s t$t ZtB2 u WB u j {B8$Rs $B RBt $? B {Bt {s s $R u W$ st RBjB R JZ? R Zt {s8}B I PZ 9s R? BjB R JZ R }Z I Z $j$9s {B8B Zts {B s9s } B { B s {Bt s 8 B $ BR u eR 8Zk R t{$jjB u -}j${? B _ BRR u qBIs js 8s $s R ? s {B8}Z R s }B s ? B8BR NBR s ? B8BR R 8st $ t t Zt$IBR }B PZ 9sR $t s ? B8${sR ej$8$t jBR s ? B8BR k I ` jsR PZ 9sR $t s ? B8${sR eR B R Zt {s8}B I PZ 9s " =ts I ht${$? Bt 8s t? h{s }B RZ R t{$jj 9 Ns R $ I jsR AZ AZ`sR I z tB z$t {B8}Z R s }B jsR tB% jsR Ns Z s I js _s9 >qY _ s{ Gs d M;H k WsZP s $B t $ 8}B sj > s BBt I $t i sj q$8 d MEH $t BIZ{ s8A$? t Zt {Z $BRB s $jZ $BU ZtBR {s8}BR I PZ 9s RP? ${BR $8} t sAj R et js } $8 s tB% js R sAB Ist jBR P { BR RB{$sj R I js s}s ${$? Bt I R sR AZ AZ`sR I { t ts R I 8 BR t Zts RB{$ IsI IB8$tsIs I${ s B $sj8 t }B jBR {$ t ? h{BR JZ {BtB{ t js {tBjB ? s }s s { s jsR et js R ZtIs tB% js I js Rs s jsR } B}$sR AZ AZ`sR RBt Z $j$9sIsR }s s %$s`s Ys{$s j PZ Z B 7$t 8As B R$ Zt R{ZIB {s8}B B }st sjjs } B { B s R I 8sR$sIB h{$ t t Bt{ R RZ ZRB }Z I R {Bt s} BIZ{ t O R$ tB JZ R jB } Zt t sj } B s Bt$R s I js }s ? BI${s tB% js I j 8ZtIB 8$j$ s $jj Y? B sj? s{ ${B > $jj psjs{ ${ < B d ExH I <s k <s $RBt Vt R I js $t8$t t As sjjs $t R js JZ tP t s ? s s jBR YZ8stBR {Bt jBR YB $Aj R {Y$t R j {s} jj? st I js ts% q 8AB R I$ $ s $jj Y? B s js PZ 9s k R} {$sj$R s I R - s {jsR t PZR$Aj RU "zs {Bt s jsR tB 8sR } B ZtB $ t JZ I RtZIs R B {B{ R * Rt? ZIs Y$`B B 8B $ ? sR R$t YsA Rsj%sIB * A 8BR R s s }Zt B I t s t s{{$? Bt ks JZ Yst }Z R B jBR R{ZIBR *$ {$R$ R{ZIBR I PZ 9s Zt R{ZIB j { B8s t? ${B Zt {sR{B Aj$tIsIB IBAj k Zts I j sIs {s}s I js $ts }R ZIB%$%$ t JZ 4Zk k {$ s {ZsjJZ$ sA Z s ]Bt BIB RB tB Ysk js 8? sR 8? t$8s }? I$Is I t ? s I RI js ts% t$ PB 8s sj Zts t JZ j$A s R I jjs W$ I j {sjB ]Bt jBR 8B B R t 8s {Ys k BIB j 8ZtIB RZIstIB j {sjB }Z I jj s s R AsR st PZ " VZtJZ t j js B =t st$jjB sj I IB I j 7Bj yRss{ VR$8B% $8s $ts ZtsR {BtR {Z t{$sR sI${sj8 t I$P t R {sZRsIsR }B js P { $%$IsI I j {s8}B I PZ 9sU "u 7 Ys PsA ${sIB Zts ts% JZ R ? s JZ$}sIs }s s jj s R? BjB s $t s 8$jjBt R I ,$j? B8 BR I j 7Bj k JZ }BI ? s 8st t R $tI ht$Is8 t s R s I$R st{$s u 5+Z? {jsR I ts% R2 u 5]? B8B JZ$ JZ kB jB R }s2 WB 8 Y R{s}sIB I t$t ? Zt jsAB s B $B _B jB JZ 8 Yst I${YB 8$ Zts R} {$ I {s8}B 8s t? ${B JZ I R%? s jsR sI$s{$Bt R I j 7Bj sj I IB I js ts% 5NB t $ tI 2 qBIB R I R%? s ej {sjB tB jj s _Z I R } 8st { sjj? }s s R$ 8} k R s 8? sR P R{B JZ t WZ %s OB , " ej {s8}B I 4 { B Z $j$9sIB R P { $%B R? BjB {ZstIB R Ys jj sIB s Zts {$ s I$R st{$s I j 7Bj _ B sj s{ Zs {B8B Zt "s t }ZjR$%B I jsR sI$s{$Bt R j { B8s t? ${sR" Ps%B { js }? I$Is I {sjB I js ts% JZ tB tI ? s t$t Zts s}B s{$? Bt {sjB ? h{s I j - $B k R $ ? s tP $stIB Nj ? stIBR {B8B I R{ $A VR$8B% s Zts R$ Zs{$? Bt }s sI? B`${sU sj s{ {s R sj 7Bj js 8} s Z s I t B I js ts% R ? s {sIs % 9 8? sR As`s g_BI ? s 8st t R s t$% j R Bj sAj R }s s RZR B{Z}st R 8$ t sR PZt{$Bt t jBR I$R}BR$ $%BR I {sj Ps{{$? Bt
© Los autores, 2001; © Edicions UPC, 2001.
@@
* $t Bt s e$tR $t
NBR {s8}BR j? { ${BR k 8s t? ${BR }Z I t s{ j s k P ts }s ? {ZjsR $t{jZRB I R%$s jsR I RZ sk { B $s B $ $tsj s {BtI${$? Bt I JZ R s I }s ? {ZjsR {s sIsR j? { ${s8 t w{B8B j { Bt R B } B Bt RD ej ZAB I skBR {s ? BI${BR wPZtIs8 t B I js j %$R$? BtD j R} { ? B sPB I 8sRsR B jBR 8BI tBR s{ j sIB R I }s ? {ZjsR RBt sj ZtBR I jBR ZRBR s}j$T {sIBR I R s } B}$ IsI 5_BI ? s Z $j$9s R Zt {s8}B j? { ${B }s s I$R K ts Zts }st sjjs I PZ 9s {s}s9 I I$RZsI$ s Zt Y$}B ? ${B s s{st I js $tZ $j$IsI I RZ s{{$? Bt2 et js } j? {Zjs qY q$8 q s% j R >d E;H jBR RZ} %$%$ t R YZ8stBR I j sK tB 1(d Z $j$9st Zt {s8}B j? { ${B % ${sj {B8B }st sjjs } B { B s }s s $8} I$ j s{{ RB sj PZ $B IBtI R B{Zj st et Zts R {Z t{$s I j hj8 R jst9s Zts }$ I s RBA R s }st sjjs $t%$R$Aj I 8st s JZ js }$ I s AB s {B8B R$ YZA$ R {Bj$R$BtsIB {Bt s Zts R? Bj$Is }s I 5eR R B }BR$Aj 2 7? BjB Zt BA` { B {s sIB j? { ${s8 t }Z I % R sP { sIB }B js } R t{$s I Zt {s8}B j? { ${B =t BAT ` B j? { ${s8 t t Z B tB {BtIZ{ B {B8B Zts }$ I s tB i RZj s I$P? {$j } tRs JZ Zt {Z }B I R sR {s s{ ? R ${sR -} $8 t jBR P { BR 8BR sIBR t js } j? {Zjs PZtIs8 t sjT 8 t t jB JZ R h s Zt $8} BAsAj AB =t {s8}B j? { ${B tZt{s }Z I ` { j }s} j I Zts }s I R? Bj$Is RBA js {Zsj {Bj$R$Btst BA` { BR tB {s sIBR j? { ${s8 t {B8B Zts }$ I s 7$ Zt {s8}B j? { ${B tB R$ % {B8B R{ZIB } B { B h{$ t }BI ? s8BR } tRs JZ sj % 9 Zt {s8}B 8s t? ${B A$ t }BI ? s sj$9s R {B8 $IB NBR 8s $sj R I tB8$tsT IBR P B8s t? ${BR 8 sj R {B8B j Y$ B j {BAsj B k j t$JZ j B RZR sj s{$Bt R } R t st Zts R Z{ Z s I IB8$t$BR 8s t? ${BR JZ Ys{ JZ $t s{{$Bt t I PB 8s tB sAj {Bt Zt $8? st B Zt {s8}B 8s t? ${B t t sj VR? Zts } ? s{ ${s I P tRs {Bt s ts% R $t%sRB sR {BtR$R $ ? s t h`s Zt }B t $8? st t $ s JZ s s ? s s BIBR jBR BA` BR I ts Z sj 9s P B8s t? ${s JZ R s{ {sR t jB RZh{$ t eR s $I s R ? s t js AsR I j h{s9 I$R}BR$ $%B I s sJZ 8}j sIB IZ st js $t%sR$? Bt sj$ t? ts I R{ $ s t VZP 9b $ }jst t >dM H tB% js }$Bt s I Z I NsRRb$ 9 =t j { B$8? st I$R}BR$ $%B {BtR $ Z$IB }B Zt t? Z{j B I 8s $sj P B8s t? ${B wY$ B IZj{ }B ` 8}jBD BI sIB }B Zt ABA$tsIB I {sAj {BtIZ{ B }B j {Zsj R Ys{ {$ {Zjs Zts {B $ t j? { ${s R %$ ? s }s s js 8$R8s PZt{$? Bt et j hj8 ]Y k 1((( >d MEH Zt Z}B I I t sIBR RZ} %$%$ t R I Zt YBjB{sZR B tZ{j s Z $j$9st {Zsj {Ys s BR I j PZ Z B Zt }B t j { B$8? st }s s {s} Z s jBR {B{Y R I jsR AstIsR $%sj R 5]Z? sj R ? s j P { B I Zt {s8}B 8s t? ${B RBA Zts Asjs2 NsR AsjsR {Bt% t{$Btsj R R PsA ${st I }jB8B w -{ } B {B8B BIB j 8ZtIB RsA jsR JZ R Z $j$9st }s s s{sAs {Bt jBR YB8A RTjBAB JZ RBt I }js sD k I B BR 8s $sj R tB P B8s t? ${BR WB RBt }B st B s s? IsR I PB 8s s} {$sAj }B jBR $8st R B j { B$8st R ]Bt BIB R }Z I Ys{ j %$ s BA` BR I R $}B Z $j$9stIB sI$ t R I {s8}B 8s t? ${B w{B8B R Ys{ I Y {YB t jsR Asjst9sR 8s t? ${sR }s s I 8$ts sj ZtsR } B}$ IsI R P? R${sR I jBR 8s $sj RD 7$t 8As B RZj s I$P? {$j { JZ }B Zt jsIB R P t? B8 tB R s tB sAj RBA Zt BA` B 8s{ BR{? B}${B {B8B Zts }$ I s {BtR $ Z$IB }B 8s $sj R {Bt } B}$ IsI R I$P t R _B B B jsIB j I$R K tB I Zt I$R}BR$ $%B {s}s9 I s}st sjjs sj 8$R8B $ 8}B 8s $sj R 8s t? ${BR {Bt } B}$ IsI R 8Zk I$P t R } R t s R $BR $t{Bt% t$ t R {tBj? B ${BR V? Zt t j {sRB I JZ R BR }ZI$ R t RBj% R BA` BR {B8B Zts Asjs jst9sIBR s st % jB{$IsI R ? st I$P? {$j8 t }s sIBR st R I sj{st9s RZ BA` $%B htsj et js {? j A } j? {Zjs Ns Z s I jBR 8ZtIBR >Gs BP Y GB jIR d xnH AsRsIs t js tB% js YB8? Bt$8s I G jjR jsR ts% R 8s {$stsR JZ $t%sI t js q$ s Z $j$9st R tIBR Aj$tIs` R 8s t? ${BR }s s } B R I jBR I$R}s BR I P tR$%BR P { ZsIBR }B jBR YZ8stBR {st$R8B R$8$js sj JZ } R t s ytI } tI t{ *sk
© Los autores, 2001; © Edicions UPC, 2001.
1 =ts BI$R s t j R}s{$BU I j et } $R sj <sj{? Bt $j ts $B
@@n
}s s I P tI jsR }BI BRsR ts% R sZ-$j$s R sj$ t? tsR NBR $t t BR I R R} sIBR I jBR 8$j$ s R }B P ts js $t%sR$? Bt - s R R sIZ{ t t j jst9s8$ t B I Zts AB8As s ? B8${s _ R sj sZ8 t B } t $tB I js 8} s Z s I j B I t I d( 8$jjBt R I sIBR t j { t B I js -}jBR$? Bt j Z}B I ts% R 8s {$stsR s%st9s I 8st s $8}js{sAj 7 Ys{ I$P? {$j } tRs JZ? $}B I 8 {st$R8B }Z I R$R $ js Bjs I {sjB } BIZ{$Is }B Zts I Bts{$? Bt } tRs ? st ZR I R JZ jBR 8s $sj R 8s {$stBR }Z I t {BtR Z$ jB } B {BtB{ ? st tZ{j s wR? JZ R B tB R Zts -}j${s{$? BtD O s? Zt 8? sR R$ A$ t j R{ZIB 8s t? ${B }Z I I R%$s }s ? {ZjsR {s sIsR {B8B j { Bt R B } B Bt R tB tI ? s t$t ? Zt P { B I s}st sjjs8$ t B RBA j 4Z`B I t Z Bt R skBR B skBR } BIZ{$IBR IZ st js -}jBR$? Bt JZ j? B ${s8 t RZj s ? st ZjB xD V Z8 t BR }s {$IBR } 8$ t s V YZ ] ]js , 8B sj R }s s jBR $t%sRB R w]s}? I R{ $A$ Zts $tR? Bj$ s As sjjs jZts t ]js B I q$ sU js AsR YZ8sts t js NZts Z $j$9s {s8}BR j? { ${BR k 8s t? ${BR }s s I R%$s skBR $? Bt${BR {BtR $ Z$IBR }B }s ? {ZjsR {s sIsR e-$R Zt I$R}BR$ $%B ts Z sj JZ } 8$ I R%$s js sk { B $s I jsR }s ? {ZjsR {s sIsR JZ } B{ I t R I j R}s{$B - $B R s{ {st s js q$ s k JZ {BtR $ Zk t jBR jjs8sIBR skBR {? BR8${BR 7 s s I jBR {$t Z Bt R I zst Vjj t I R{ZA$ BR }B j Rs ? j$ s $h{$sj tB s8 ${stB e-}jB t j sK tB d xM k stsj$9sIBR {Bt }BR $B $IsI }B js RBtIs _$Bt yyy i {$A t R tB8A jsR I$% RsR 9BtsR I j t B tB R IBtI jBR j { Bt R k jBR } B Bt R JZ Ist {BthtsIBR }B P { B I j {s8}B 8s t? ${B R ej {$t Z ? Bt $t $B R - $ tI t jBR M(( ,8 k jBR ;!((( ,8 I js RZ} h{$ R $ t sR JZ j - $B R - $ tI YsR s ZtBR E(!((( ,8 I js q$ s Ns -$R t{$s I }s ? {ZjsR {BthtsIsR t R sR $Bt R Is jZ s sj %$R BRB P t? B8 tB I jsR sZ B sR AB sj R AstIsR jZ8$tBRsR I {BjB R JZ B{sR$Btsj8 t }Z I t R BAR %sIsR t jsR 9BtsR { {stsR s jBR }BjBR 8s t? ${BR R R eR R} { s{Zjs P t? B8 tB R B $ $ts }B js {Bj$R$? Bt t }s ? {ZjsR {s sIsR I jBR {$t Z Bt R I sI$s{$? Bt k jsR 8Bj? {ZjsR I B-? tB B t$ ? B tB } R t R t js s 8? BRP s Ns I R -{$ s{$? Bt I j B-? tB s I$P t R sj Z sR R sIZ{ t PB 8s I 8$R$? Bt I PB Bt R {B R}BtI$ t R s js jZ9 % I B B`s 8$ t sR JZ js 8Bj? {Zjs I t$ ? B tB R I R -{$ s 8$ $ tIB t js P {Z t{$s {s s{ ? R ${s I js jZ9 B`s Ns {B8A$ts{$? Bt I R BR } B{ RBR I I R -{$ s{$? Bt R js R}BtRsAj I js $t{ ? Aj {BjB s{$? Bt I j h 8s8 t B JZ Is jZ s sj P t? B8 tB I jsR sZ B sR AB sj R ej hj8 z$s` sj PBtIB I j 8s >zBks B Y B B8 BP Y 7 s d EdH JZ $tR}$ ? B js }BR $B R $ j %$R$%s R $t${$s {Bt Zt RB } tI t s Z8 t BU js $}Zjs{$? Bt I j Zj s8BI tB RZA8s $tB 7 s%$ b I A jst9s Zt 8$R$j tZ{j s }s s s}s s j PZ B JZ s9B s gjBR {$t Z Bt R I zst Vjj t =t $t{ tI$B JZ jBR Z$Bt$R sR I js } j? {Zjs ks }Z R BR s $AZk t sj }sRB B{sR$Btsj I R tIBR 8 B $ BR 5<st } BAsIB sj Zts % 9 s t{ tI j s$ {Bt Zts { $jjs2 ]B8B Y 8BR I${YB j {$t Z ? Bt $t $B R - $ tI 8? sR sjj? s I jBR M(( ,8 I sj $ ZI {$P s JZ AsRs {Bt { { R jBR j? 8$ R I js s 8? BRP s R w t x( k n(( ,8 I sj $ ZID $ t }B{B JZ Is }B $t{ tI$s s sj R t$% j R yI sIBR }s s } B s $tI$%$IZBR ts% R B {$ZIsI R t sR k 8 I$B {Bt s jBR 8$Aj R skBR I js 8Z B jBR skBR s{ B R k ZRZsj8 t {Bt s sj B 8? sR } BRs${B {B8B jsR AsjsR js P { $%$IsI I jBR R{ZIBR I PZ 9s Ys I `sIB 8Z{YB JZ I R s Vt j s sJZ I Zt Y$}B ? ${B skB I js 8Z tsIs 8 `B JZ I$R}Bt I Zt R$8}j R} `B {Bt% t$ t 8 t B $ t sIB j {Zsj }Z I sj$9s js 8$R8s PZt{$? Bt I P tR$%s et jsR } $8$ $%sR R $ R I e e 78$ Y 7,kjs , k N tR8 t R $t BIZ{ t ks jsR jsR JZ IZ st Zt {$ B $ 8}B $ ? st
© Los autores, 2001; © Edicions UPC, 2001.
© Los autores, 2001; © Edicions UPC, 2001.
1 =ts BI$R s t j R}s{$BU I j et } $R sj <sj{? Bt $j ts $B
@@N
j {B8}B s8$ t B I R BR s $jZ $BR ]ZstIB jBR {s8}BR I PZ 9s RBt s s{sIBR R B tst $t{stI R{ t R k sIJZ$ t Zts Btsj$IsI B`$9s k sts st`sIs JZ Is }sRB jZ B s BIBR jBR {BjB R I j R} { B jj stIB YsR s j %$Bj s k j t B }s s s{sAs I R}jB8? stIBR k R sjjs t Zts }$ B ? t${s s{s htsj N 8BR t _ ? B-$8s ] t sZ $ >_ B-$8s ] t sZ $ d nxH I Z sk N $tR U "ej {sR{B I j VIsR s s I s{ B I sj s{$? Bt R$R t k t { Rs $s8 t I st Y$R ? R$R NsR {B $ t R j? { ${sR sj tsR $tIZ{$IsR t j s{ B }B js sI$s{$? Bt { t Z $sts YsA ? st {sj t sIB $t{jZRB Zt {sR{B I {BA _ B j s{ B I sj s{$? Bt R {sj t ? B 8Z{YB ]s8A$? B I {BjB k R }ZRB sj B`B Zts 9Bts I $t s 8 BR I I$? s8 B > H ej A $jjB B`B 8s I j s{ B sZ8 t ? B 7 Y$9B {s 8 R? N t s $t -B sAj 8 t sj{st9? B Zt $t s8s $jj t B 7 %Bj%$? B Ajst{B %$ ? B sj s9Zj > H ej {sR{B - $B R I $ $? B ej s$ $t $B PZ -} j$IB sj %s{? B `Zt B {Bt P s 8 t BR %BjB st R I 8 sj t PZR$? Bt" z$R s RZ }B{s { I$A$j$IsI k jB $tt { Rs $B I j P { B sK tsI$IB R s {s s{ ? R ${s } Bt B R ? s sAstIBtsIs y Zsj8 t $t% BR? 8$j R sZtJZ 8Z{YB 8? sR $t t$BRsR RZj st jsR } B}$ IsI R I j {s8}B I PZ 9s $I sIB }B ]Ys j R <s t RR t 3j$ Y $t B O R Isk >d ;(HU js h{s{$s I j {s8}B I PZ 9s R } B}B{$Btsj s js {st $IsI I 8B%$8$ t B w} BIZ{ B I js 8sRs }B % jB{$IsID I j BA` B sj JZ R$R eR s } B}$ IsI } B}B {$Bts sj sZ B Zts AZ ts -{ZRs }s s $t BIZ{$ ts {st $IsI I 8B%$8$ t BD t Zts RB{$ IsI {tBj? B ${s8 t jBR {B8As R {Bt R}sIsR w} JZ K s%st9sIs ej I$R}BR$ $%B JZ } R t s _BZj VtI RBt t 7Y$ jI >d EnH }Z I {s s RZR As ? sR s} B% {YstIB js t ? s {$t? ${s JZ }BR t jsR AsjsR JZ j {s8}B { sIB R {s}s9 I }s s 7$ jBR R{ZIBR k {s8}BR I js h{{$? Bt } R t st {$ BR $t{Bt% t$ t R t {Zst B s RZ }BR$Aj sj$IsI P? R${s }B jBR 8 tBR }BI 8BR Z $j$9s jsR } B}$ IsI R I jBR 8s $sj R j? { ${BR {BtIZ{ B R }s s s$Rjs tBR I js $t4Z t{$s I Zt {s8}B j? { ${B - $B et j $t $B I Zt 8s $sj {BtIZ{ B j? { ${B j {s8}B j? { ${B R tZjB et BIB 8B8 t B js {Bth Z s{$? Bt I js {s s j? { ${s w j { Bt R j$A RD t js RZ} h{$ I j {BtIZ{ B R sj JZ R stZjs j {s8}B j? { ${B t RZ $t $B et js $? Bt $t $B R s 8BR j$A R I js $t4Z t{$s j? { ${s } B{ I t I j - $B $ t sR JZ tB R }Z I {BtR Z$ Zt R{ZIB {Bt s js s% IsI }B JZ ? R s R$ 8} s s wtB Ysk s% IsI }ZjR$%s }s s stZjs js s% IsI s s{ $%sD RZj s t {s8A$B js $%s8 t R t{$jjB {BtR Z$ Zt R{ZIB }s s R Zs Is R I j {s8}B j? { ${BU AsR s BI s R I Zt {BtIZ{ B j? { ${B _B RB jBR {B8}Bt t R j? { Bt${BR %$ t t t {s`sR 8 ? sj${sR k {$ BR {sAj R $ t t Zt % R $8$ t B I 8 sj eR sR {ZA$ sR 8 ? sj${sR R$ % t }s s } B jBR I jBR {s8}BR j? { ${BR - tBR Ns } BPZR$? Bt I I$P t R {s8}BR I PZ 9s tB 8sj8 t I ? tIBj I P tR$%s }Bt I 8st$h R B j $t t$B I R{ $ B R k Z$Bt$R sR t Zt $t t B I Ys{ P t s jsR s 8sR {sIs % 9 8? sR RBhR ${sIsR k 8B ? P sR {Bt jsR JZ R ? Zt }s { {Bt s ? st jBR 8sj%sIBR I j PZ Z B V Psj s I tsIs 8 `B JZ t js sj$IsI RZ} s js h{{$? Bt js 8 `B I P tRs R$ Z R$ tIB Zt AZ t s sJZ wB }Bt jBR }$ R t }Bj%B BRs {js BD et I ht$ $%s R s s I s Ps{ BR sI R JZ {B8B A$ t I${ t FBYt ]jZ k _ W${YBjjR t RZ 8BtZ8 t sj qY et{k{jB} I$s BP 7{$ t{ 3${ $Bt "skZIst s {Bt s Y$R B $sR"@@
et js } j? {Zjs I NZ$R ZK tZ j ej s ?t j - 8$tsIB tB R Zts }st sjjs P? R${s js JZ $8}$I s %s $B}$t BR } RBts` R I js sj s RB{$ IsI s s% Rs j Z8A sj I js {sRs t js JZ R Yst IsIB {$ s }s s { ts R$tB sj B $tI ht$Aj JZ }s { R$I$ t j $t $B I {sIs ZtB @@
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
dd
n
* 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
7BA $8} BAsAj R }sjsI$t R I j A$ t {Bt 8? ZR{ZjBR I s{ B s $jZ $BR JZ RB st jBR j? 8$ R I js P? R${s k RZ} %$jjstBR B{Zj BR }B }? B{$8sR I $t%$R$A$j$IsI
y tB B j $ 8}B JZ s Is ? t $ZtPs } B sj {sAB RsjI 8BR I R s st ZR $s I {sIs I? s I R s R %$IZ8A P? R${s k 8B sj t JZ tBR s sR s8BR }s s t{Bt s Zt RZR t B 8 9JZ$tB $ R tIs R ? s $ 8 I$sAj 8 t s9sIs TO 5JZ? %sR s Ys{ 2 T5+Z? %Bk s Ys{ 2 _Z R R Z$ Rs R tIs T5+Z? R tIs V8s B2 TNs R tIs I jBR 8sjBR ? s 5WB R jB Y I${YB2
G t{ RjsB 3 t? stI 9 3j? B 9
ej 8sj%sIB ]s sA j
>d ExH
wy9JZ$ IsD 7Z} 8st s JZ $}B I Rs j $? Bt I sAt sIBR I P tRB R I j A$ t JZ {BtR $ Zk t jBR RZ} Y? B R * js } j? {Zjs 7Z} 8st yy >7Z} 8st yy qY VI% t Z ]Bt $tZ R d M(H
© Los autores, 2001; © Edicions UPC, 2001.
ddM
* $t Bt s e$tR $t
=t I? s {ZsjJZ$ s t Zts {$ZIsI {ZsjJZ$ s FZst R Ysjjs t j sjP? $9s I js % t sts I RZ jZ`BRB s}s s8 t B Zt I? {$8B }$RB R$ B t Zts {? t ${s s% t$Is I js {$ZIsI eR ? ss }Zt B I Is j }sRB 8? sR $8}B st I RZ %$Is ej Z ?j $8B }sRB JZ j sj `s ? s sj ht I Zts sj$IsI JZ I R s AB s {Bt js $t -$R t{$s NB Yst I R} I$IB I j sAs`B RB R? {Bt Zts RZ{Zj t s $tI 8t$9s{$? Bt JZ ? s}$Is8 t Ys } I$IB `Z stIB s js Zj s et{$8s RZ 8Z` jB Ys sAstIBtsIB }B RZ 8 `B s8$ B O t j Ps ? I${B $tR st t JZ B8s js I {$R$? Bt I Rsj s sj %s{? B {ZstIB js 8Z{Y IZ8A {Bt sIs t js {sjj }s s } R t{$s j % t B `sj s sj RZ${$Is }s s JZ tB }BR Z }B 8? sR $ 8}B j R} { ? s{ZjB s}s { 5Zt }? s`s B2 5Zt s%$? Bt2 gWB eR 7Z} 8st FZst {B $IB t %BjstIsR t j 8B8 t B 8$R8B I $t${$s js {s? Is tB $ t $ 8}B I s{{$Bts ]Bt B`BR s ? Bt$ BR {Bt 8}js {B8B sR Zt {B B %Z jB j RZ} Y? B jB I }BR$ s RZs% 8 t t j RZ jB ! s %$Is Rsj%sIs B B s{ B I A$ t }s s R s I Rs sI {$Is YZ8st$IsI ej YB8A I s{ B tB R} s t$t ? Zt s sI {$8$ t B qsj {B8B Ys % t$IB R %s WZ %BR s{ BR Y B${BR JZ$ t RZ } R t{$s ej }? ZAj${B s}jsZI 8$ t sR FZst {sA$9As`B 8sjI${ RZ AZ ts RZ k j I? s t JZ I {$I$? B h`s RZ R$I t{$s t js 8$R8s {$ZIsI JZ 7Z} 8st "gW$ RZ${$Is R j I `st s ZtB " %s 8Z 8Z stIB 8$ t sR R sj `s <sA$ Zsj8 t t tI 8BR }B RZ} YB8A s sJZ j PB t$IB } RBts` I s}s $ t{$s 8? sR B 8 tBR YZ8sts JZ B{Zj s RZ $I t $IsI As`B Zt R sPsjs $B s` R$t t { R$IsI R hR$Bj? B ${sR s}s t R k I sR} { B RsjZIsAj JZ s{$sR s {$ BR RZ} }BI R B YsA$j$IsI R wsIJZ$ $IsR B $tts sRD RZ} $B R s jsR I Zts } RBts tB 8sj R {s}s9 I sj$9s s{{$Bt R JZ RZj st I j BIB $8}BR$Aj R B I Zts - 8s I$h{Zj sI }s s j {B8? Zt I jBR 8B sj R ]ZstIB Ys{ ZRB I R sR YsA$j$IsI R t 8$R$Bt R {BtR$I sIsR 8B sj8 t {B { sR j RZ} YB8A {$A j tB8A I RZ} Y? B et {ZsjJZ$ B B {sRB R {Bt%$ t Zt RZ} 8sj%sIB B RZ} %$jjstB eRBR RZ} }BI R I B $ t 8? sR B 8 tBR $t{$ B j Ys{ t R I$P t s B BR Y? B R sj ZRB {B8B j ]s}$ ? st q Z tB j V t (( B ytI$sts FBt R JZ$ t R } R s R s A$ t t tsIBR k t t sj ZtBR {sRBR s RZ I$R}BR${$? Bt s $jZ $BR {tBj? B ${s8 t s%st9sIBR tB RBt 8? sR JZ YZ8stBR B I$ts $BR et j s JZ $}B I RZ} YB8A R Ysjjs } R t js I${B B8? s -$R t t j A$ t k j 8sj js Y B${$IsI k js %$jjst? s ej RZ} Y? B I js h{{$? Bt $ t RZ B $ t t jBR {? B8${R k t {Bt{ B t jsR $ sR }ZAj${sIsR }B jBR } $? BI${BR tB s8 ${stBR $ t } Bt B R$t 8As B jj s ? s sj }? ZAj${B t t sj s{$sR s jBR R $sj R B } j? {ZjsR }B }$RBI$BR JZ st B ? -$ B Z%$ Bt t js I? {sIs I jBR n( VZtJZ jsR Y$R B $sR I RZ} YB8A R R 8Bt st s } $t{$}$BR I R$ jB js % R$? Bt I j 8BI jB ? }${B I RZ} YB8A JZ Ys sR{ tI$IB YsR s tZ R BR I? sR }Z I R$ Zs R t j sK tB d nM {Bt js }ZAj${s{$? Bt I V{ $Bt ]B8${R IBtI 7Z} 8st j YB8A I s{ B Ys{ RZ } $8 s s}s ${$? Bt Zk } Bt B j } RBts` tI ? s RZ } B}$B {? B8${ s js }s JZ s}s { ? st 8? Zj $}j R $8$ s{$Bt RU <Z8st qB {Y >d n H ]s}$ ? st s % j >d ;(H ]s}$ ? st V8? ${s >d ;dH GBtI GB8st >d ;1H _jsR ${ st >d ;;H k B BR <sR s htsj R I jBR sK tBR {Zs t s R s }stB}j$s I Pst ? sR ${BR } RBts` R %$%$ ? st Zts ? }B{s IB sIs tP t ? stIBR s jBR 8sjBR sj RU jBR ts9$R 3$ j 4 `B I jsR PBA$sR I js RB{$ IsI tB s8 ${sts R BR t 8$ BR R ? st 8}js9sIBR }B js s8 ts9s {B8Zt$R s k j 8$ IB sj }BI s ? B8${B k s js $t%sR$? Bt - s R et jBR sK tBR R R t s k YsR s A$ t t sIBR jBR R t s R %$%$ ? s Zt R ZtIB ts{$8$ t B {Bt js s}s ${$? Bt I s Z}s{$Bt R I RZ} Y? B R s{BR Z8A sIBR }B jB t sj s RBj% t Z BR s ? ZjB $tI$%$IZsj sj R {B8B FZR ${ N s Z BP V8 ${s k NBR ]Zs B 3st ? sR ${BR >3st sR ${ 3BZ d EdH k I B BR
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
@@
RZ} Y? B R RBj$ s $BR JZ sj{st9s ? st } Bt B js {$8s I j ? -$ B {B8B 7}$I 8st >V8s9$t 7}$I 8st d EnH Z{YsR I jsR R $ R I j %$R$? Bt k I jsR } j? {ZjsR } B s Bt$9sIsR }B R BR $t PsAj R } RBts` R R sj$9s ? st IZ st R s ? }B{s NsR $IsR k % t$IsR I jBR I$AZ`st R k Z$Bt$R sR jBR } BAj 8sR {Bt jsR I$ B $sj R }B js }s t$IsI I RZR { s{$Bt R js Psj s I $I sR }s s {Bt $tZs jsR t 8Z{YBR {sRBR sjs8A${sIsR R $ R t B sR {sZRsR } B%B{s ? st j {$ I jsR {Bj {{$Bt R 7Z s} Z s {Bt tZ %sR % R$Bt R I jBR } RBts` R JZ jj st $t{jZRB s {Bt%$%$ {Bt jBR st $ ZBR I${$Bt R `ZR $h{s{$Bt R { s{$? Bt I Zt$% RBR }s sj jBR }s s 8st t js {BY t{$s I jsR Y$R B $sR JZ R {Z t st k t s{ $%B s BIBR jBR RZ} Y? B R I Z tB B $ $tst Zt {sBR k Zt 8s sR8B I$ B $sj I$P? {$j I I R t sK ts $t{jZRB }s s jBR h j R j { B R _B ` 8}jB js stZt{$sIs 8Z I 7Z} 8st t d n k RZ }BR $B RZ {{$? Bt R Zts AZ ts 8Z R s I j s{ AB I jsR I$ B $sj R }B R Z$ 8st t$ tIB %$%s js }B}Zjs $IsI I s s Zt JZ$BR{B s{sAs ? s }B R BR } {Zj$s R } RBts` R@ ]ZsjJZ$ s JZ R s{ JZ YBk t I? } I R t js 8Zj $ ZI I I$RP s{ R 8Zj ${BjB R w j {BjB Ys RZAR $ Z$IB sj Ajst{B k t B B R s{ Zsj R I jBR {? B8${R B $ $tsj RD k jBR 8s s%$jjBRBR }BI R I JZ Ys{ t sjs jBR RZ} Y? w8Z{YBR I jjBR {Bt {Bj {{$Bt R } B}$sRD 8BR stIB js AZ ts RsjZI I j ? t B B }B jB 8 tBR js -$R t{$s I Zt }? ZAj${B }B t{$sj I R BRB I s% t Z sR R$t I 8sR$sIsR {B8}j${s{$Bt R ej } $IB Rsj B s js st }st sjjs I jBR 8? sR {BtB{$IBR {B8B 7Z} 8st s8A$? t Zts 8Z R s I RZ }B}Zjs $IsI ]s8} Bt R I j A$ t s Bj} I 8s8}B B } R s JZ$ t } R k {s$ s JZ$ t {s$ s R BR Y? B R }B jB t sj t8sR{s sIBR R t{Z t st sJZ? }s s I P tI s js YZ8st$IsI I jBR %$jjstBR I Z tB JZ I R st s}BI s R k IB8$ts j 8ZtIB =ts % 9 {Z8}j$Is RZ 8$R$? Bt I Rs}s { t R$t I `s j 8? sR 8? t$8B sR B I RZ } R t{$s I {j$tstIB {ZsjJZ$ {BtB{$8$ t B I RZ ? 8} BAs jsAB eRs 8BI R $s 8st$h R s j R BAj$ s s B{Zj s RZ $I t $IsI jj %stIB Zts IBAj %$Is JZ jBR Ys{ s{ IB R I Zts %$Is RB{$sj } BAj 8? s ${s WB R s B {Bt 8}js {? B8B R BR R R 8BI? j${BR {$A t R$ tsIBR s}s}Bj%BR I RZR ` P R }B RZ sAs`B {B8B {$ZIsIstBR tB 8sj R k s{ } st j 8sjYZ8B I RZR R} { $%sR s8sIsR JZ tB {B8} tI t RZR R? ZA$ sR k } BjBt sIsR I Rs}s ${$Bt R 7Bt jBR {sRBR I 7Z} 8st k 7}$I 8st O R JZ {js B R Zt RZ} Y? B $ t s8A$? t Zt } {$B O ks }Z R BR s sI${s js 8sjIsI t js q$ s ZtB R } Zt s 5}B JZ? tB Z $j$9st RZR }BI R }s s 8 `B s j 8ZtIB R I {$ s s{stIB sj 8sj t RZ s? 9 k tB s{ ZstIB {B8B 8 BR } RB R I {ZsjJZ$ I R%$s{$? Bt I j R s ZR JZB R sAj {$IB2 V {Bt $tZs{$? Bt stsj$9s8BR jsR w$8D}BR$A$j$IsI R JZ B B st s RZR }BR IB R RsR YsA$j$IsI R 8? s ${BTPst ? sR ${sR k jsR }B t{$sj$IsI R I jBR s $jZ $BR JZ 8Z{YBR I jjBR Z $j$9st 5e-$R t j? 8$ R P? R${BR s jBR }BI R I Zt RZ} YB8A 2 s 8st B 7}$I 8st w{Bt {Zs B hj8 R s RZR R}sjIsR jBR IBR } $8 BR k R j R ZtIB }B j 8B8 t BD RBt
n d
3jsRY j j? s8}s B YZ8stB
s k Vjj t Zt {$ t ? h{B JZ sAs`s }s s j {Z }B I }Bj${? s I ] t sj ]$ k RZP Zt s{{$I t t RZ jsAB s B $B s {BtR {Z t{$s I js {s? Is I Zt skB ej {Bt s{ B {Bt {$ BR } BIZ{ BR JZ? 8${BR k j P { B j? { ${B I j skB jB {Bt%$ t t Zt RZ} Y? B {s}s9 I
=t {BtR Z$IB $t t B }B }Bt B I t t js sj ? s I RZ} Y? B R jB {BtR $ Zk j *${{$Bts $B I 7Z} Y? B R >d EH {BtP {{$BtsIB }B NB t9B *? s9 @
© Los autores, 2001; © Edicions UPC, 2001.
@
* $t Bt s e$tR $t
3$ n d =t RZ} Y? B {B8B 3jsRY JZ }BR js } BI$ $BRs Ps{Zj sI I {B s Zts st % jB{$IsI tB }Z I $ }B sY? % R $IB I {ZsjJZ$ 8st s ej {sjB t sIB }B js P ${{$? Bt {Bt j s$ j BAj$ s s Z $j$9s Zt s Z tIB 8? sR } ? s{ ${B wsZtJZ }B{B I$R{ BD
I R}js9s R s js tsIs I RI K tsAj % jB{$IsI I g (( ,8>Y q sR j s{{$I t Vjj t t s t {Bt s{ B {Bt js IB{ B s ] $R $ts {p $t% R $ sIB s I js I$%$R$? Bt A$B{$t? ${s I jBR NsAB s B $BR 7 s FZt BR R tP t st s jsR $AZR Z AstsR JZ {s8} st s RZR st{YsR }B ] t sj ]$ k =t RZ} Y? B s{sAs I ts{ ]Bt R BR $t I$ t R ks t 8BR j 8s $sj I AsR }s s {BtR Z$ BIB Zt R $sj I s% t Z sR }jsR8sIB t 3jsRY j j? s8}s B YZ8stB >qY 3jsRY d (T dH 3jsRY {B8B t t sj BIBR jBR RZ} Y? B R } B{ I I j {? B8${ IBtI s}s {$? B }B } $8 s % 9 t j sK tB d ;( I js 8stB I j Z$Bt$R s ps It 3B- k I j I$AZ`st <s k Ns8} et RZR 8} stsR s% t Z sR s t{s tsIB }B j R ZI$st Fsk ps ${, JZ$ t RZP ? s j s{{$I t t R {sRB {Bt Zt } BIZ{ B JZ? 8${B {B8B j s Zs } RsIs JZ j } B}B {$BtsAs j }BI I {B s st % jB{$IsI ej } RBts` tI ? s Zts tZ %s % R$? Bt t d x ks {B8B s k Vjj t 7ZR Z$Bt$R sR Ys ? st sj$IsI jB $8}BR$Aj U R 3jsRY {B$t{$I$ ? s {Bt j B $ $tsj t ZtB I jBR t? Z8 BR I js R $ I I${sIs sj } RBts` sR sAs j {Z RB P? s{$j I gYs{ s ? R YsA$ st I Zts I$8 tR$? Bt }s sj js et d M j RZ} Y? B I `s ? s RZ }Z R B s $I 3jsRY `B% t{$ B JZ sIJZ$ ? s s{$sR s Zt s{{$I t {B8B j I RZR } I { RB R $I? t ${BR }BI R VI 8? sR I j h j t B R Z$8$ t B I JZ Ys R$IB BA` B }B }s I jBR $8} t$ t R j { B R I {? B8${R wZt ? s s{$sR s RZ }sRB s JZ sj ? Zt R ZI$BRB Ys IsIB t I ht$ {B8B j {$t I jBR }BA RD R ? js j %$R$? Bt JZ j } RBts` {$A$ ? s j R}sjIs s9B I ht$ $%B z$R s js ? t R$R Y$R ? B ${s I j } RBts` }sR 8BR sYB s s stsj$9s jsR }B t{$sj$IsI R I j }BI JZ j } 8$ R {jsR$h{sIB {B8B RZ} Y? B !A%$s 8BR t R st? sj$R$R js PB 8s t JZ j 8$R8B R sIJZ$ $IB sZtJZ t j {s}? ZjB ; %$Rs 8BR j P { B tsIs s sIsAj }B {$ B I Zt skB RBA Zt B st$R8B
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
@ @
et j } $8 }$RBI$B I js R $ j %$R$%s R % s Zt s k Vjj t $t{BtR{$ t I RZ {$? t sIJZ$ $Is YsA$j$IsI RB8 $IB s ZtsR } Z AsR 8? I${sR }B }s I js IB{ B s {p ej } BT s Bt$R s {B }B Zts {$t s R$t ht JZ 8$I RZ % jB{$IsI 8$ t sR ZtBR j { BIBR {Bt Bjst RZ s{ $%$IsI {B }B sj Ns {$t s I j I$R}BR$ $%B JZ R? BjB R ? s I$R K tsIB }s s RB}B s jsR % T jB{$IsI R ? }${sR JZ Zt R YZ8stB }Z I sj{st9s w8 tBR I ;( ,8>YD R B8} {ZstIB j s}s s B 8s {s E;( ,8>Y w{B R}BtI$ t s Zts j { Z s I ;(( 8$jjsR }B YB sD ej RZ` B Is Zt } JZ K tB Rsj B k R s s s s jsR As sR I RZ` {$? Bt js sj R O sJZ? tB Ys }sRsIB tsIs Ns RB } tI$Is IB{ B s Ys ? s A$ t t 8BR s s8A$? t RB } Rs tB R? BjB }B js % jB{$IsI $tI${sIs }B j I$R}BR$ $%B R$tB g}B JZ jBR Z$Bt$R sR Yst IsIB %s{s{$Bt R s js $t {$s ej } B s Bt$R s R I R}js9s }B js {$t s k 8st $ t Zts % jB{$IsI tZjs R} { B I j RZ jB _ R s jjB {ZstIB ? R s R B8} j B9s8$ t B {Bt RZR 9s}s $jjsR JZ } 8$ JZ }Z Is {B }B js 8$R8s R$t I Rj$9s } B%B{s ? s JZ R 8st t s Zt$IB s js {$t s Rsj$ tIB jst9sIB `Zt B sj - 8B I js 8$R8s s Zts % jB{$IsI $I? t ${s s js JZ R I R}js9sAs IstIB RZR YZ RBR {Bt s js }s I I j jsAB s B $B _B js 8$R8s {sZRs js $t {$s {ZstIB Zt s ? ABj P ts t R {B j 8B%$8$ t B I Zt % Y? {ZjB JZ R 8}B s t ? j RZR B{Z}st R Rsj t I R} I$IBR t js I$ {{$? Bt I j 8$R8B k s js 8$R8s % jB{$IsI R$ tB R ? st RZ` BR }B j {$t Z ? Bt I R Z $IsI ]js B JZ t tZ R B {sRB R s s I Zt {$? t {jZ sIB RZ} Y? B k }B jB 8 tBR YsA ? s JZ {Bt{ I j js }BR$A$j$IsI I JZ RZj $j RB sR js $t jZI$Aj {Bj$R$? Bt 7$ tB YsA 8BR Zt{sIB Zts } B8 IB s {s s k s{sAsIB I Zt }jZ8s9B wB 8 `B As s{s9BD js R $ s} tsR {B8 t9sIs et B s A $jjst R{ ts I j 8$R8B }$RBI$B tZ R B RZ} Y? B 8}$ 9s s Is R {Z t s I }s s JZ? }Z I R %$ Rs {$? t sIJZ$ $Is YsA$j$IsI ]ZstIB R I$ $ Ys{$s RZ sZ B8? B%$j R Is {Z t s I JZ $ t Zts I jsR Z IsR }$t{YsIsR 5_s s JZ? t t R t {s8A$s js k jZ B {BtIZ{$ j % Y? {ZjB }B {sjj R s R sIsR I ? sh{B2 7$ ZtB }Z I I R}js9s R s %s $BR { t ts R I ,$j? B8 BR }B YB s 5}s s JZ? t { R$ s Zt sZ B8? B%$j2 VR? JZ gI {$I $ R {B $ tIB _ B jBR Z$Bt$R sR tB Yst t$IB t {Z t s JZ jsR {sjj R I Zts {$ZIsI tB R ? st I$R K tsIsR }s s JZ JZ$ t R I R}js{ }B jjsR jB Ys s s stI R % jB{$IsI R !AR ? s{ZjBR sj 8s t jBR { Z{ R $t R {{$Bt R I {sjj R RBt {B8}j${sIsR {Z %sR t PB 8s I N s} sR }s s tB sI$B I {Z %s Z s JZ 8AB{s s 8 tBR I x( ,8>Y 7Bt {Z %sR R$t } sj k I } JZ K Ys{ t $8}BR$Aj Zts {BtIZ{{$? Bt s % jB{$IsI R 8skB R yt{jZRB t jBR {$ {Z$ BR } }s sIBR sj P { B {B8B jBR I P? B 8Zjs d IBtI R sj$9st {B8} ${$Bt R sZ B8B%$j? R ${sR RZj s I$P? {$j B tI ? s 8Z{YBR } BAj 8sR {ZstIB I As %s $s RZ} s jBR n(( ,8>Y WZ R B }BA RZ} Y? RZ sk { B $s B {$ tIB s $9JZ$ Is B s I {Ys }B jsR {sjj R _s s B8s Zts {Z %s R$t Rsj$ R I js 8$R8s I A } B}B {$Bts R sj BA` B 8? B%$j Zts PZ 9s { t ? } s 7 s s I Zts PZ 9s } } tI${Zjs sj 8B%$8$ t B k I$ $ $Is Ys{$s j { t B I js {Z %s ej B9s8$ t B t jBR t Z8? s ${BR I j sZ B8? B%$j B js RZ js I jBR 9s}s BR k j sRPsj B RZ8$t$R s js PZ 9s { t ? } s t { Rs $s }s s P { Zs j $ B Ns % jB{$IsI 8? s-$8s s js JZ Zt sZ B8? B%$j Z BA` B t 8B%$8$ t B }Z I B8s Zts {Z %s }jsts R } B}B {$Btsj sj sI$B I js 8$R8s k sj {B h{$ t I B9s8$ t B t jsR Z IsR k j RZ jB ]Zst B 8skB R R st s8ABR }s ? s8 BR s st s 8? sR % jB{$IsI }BI ? s j 8? B%$j ` {Z s j $ B R$t $ R BR 7$ j B9s8$ t B R $tRZh{$ t B j sI$B I js {Z %s R } JZ K tB j sZ B8? B%$j B j {B IB tI ? st s 8st t s{$sR s js $t {$s js sk { B $s { $j? t s $t${$sj k tB YsA ? s 8st s I Is js {Z %s * Rj$9s ? st k s{sAs ? st R jj? stIBR {Bt s js %sjjs } B { B s B j I$h{$B I tP t ej } sj sIB B $t{j$ts{$? Bt R} { B I js YB $9Bt sj I j h 8 I Zts %? s {s s B sZ B}$R s IZ{ j }s} j
© Los autores, 2001; © Edicions UPC, 2001.
@
* $t Bt s e$tR $t
I j B9s8$ t B VYB s R js {B8}Bt t YB $9Bt sj I js s{{$? Bt I j RZ jB sj } RB I j 8? B%$j wPZ 9s tB 8sjD js JZ R t{s s I } B}B {$Bts js PZ 9s { t ? } s t { Rs $s }s s I R{ $A$ js sk { B $s {$ {Zjs Ns % jB{$IsI 8? s-$8s R t R {sRB } B}B {$Btsj sj sI$B k sj s ?t ZjB B } sj ej P { B {B8A$tsIB I Zts {Z %s {Bt } sj k j B9s8$ t B } 8$ sj{st9s 8skB R % jB{$IsI R _ B }B jB JZ }s { R BR } JZ K tBR I sjj R tB Ys{ t 8 jjs t 3jsRY VAB{sIB s Zts % $ $tBRs {s s t$ R$JZ$ s js $t {$s }s { R {s}s9 I I t j _s sP sR stIB j ? ZjB I Zts tB% js I is8? Bt p? B8 9 I js 7 ts }BI ? s8BR I {$ gsY? %s Zts $t{Bt Z t{$s ! BR P t? B8 tBR R s % 9 A$ t $jZR sIBR t js R $ j %$R$%s {BA st $8}B st{$s s % jB{$IsI R j %sIsR q sR js PB 8$IsAj {s s s Zts % jB{$IsI { {sts s jBR (( ,8>Y JZ jj %s s s k $t{jZRB s I `s s ? sR j jZ s I I R $tB RZ B}s I {sjj 8Z R s A$ t s jsR {js sR j P { B I j {sj t s8$ t B I A$IB s js P ${{$? Bt {Bt j s$ VJZ jjs s}s { {Ys8ZR{sIs k Y {Ys `$ Bt R V }s $ I R }$RBI$B % 8BR ks sj } B s Bt$R s 8AZ $IB t Zt s` R} {$sj I Zt jjs8s $%B {BjB B`BU Zt % R $IB ZRB I AZ{ B R$R t s jBR {s8A$BR I } R$? Bt 8? sR s BI$t? s8${B k s AZ t R Z B {BtP {{$BtsIB {Bt sj ? Zt 8s $sj s8A$? t R$R t sj {sjB et R {sRB R ? s B sj8 t `ZR $h{sIs js t { R$IsI I 8}js9s js B}s I I$s $B }B j s` I RZ} Y? B Os tBR I$ ? st ZR I R js PB Zts JZ 3jsRY I A ? s sR s R? BjB t s` R R$ I R}Z? R I {sIs {s $ s j JZ IsR t $tR %$Aj R O RB }B tB YsAjs I RZ {sj9sIB BAj$ sIB s s{ Zs {B8B P tB {sIs % 9 JZ j RZ} Y? B I {$I JZ ks R ? s A$ t I {B U R$ BIs js t ? s {$t? ${s JZ }BR j RZ} Y? B {ZstIB R I R}js9s stRPB 8sIs t {sjB }B j B9s8$ t B {ZstIB P ts t R {B PZ R sARB A$Is }B RZ {Z }B RZ 8} s Z s {B }B sj sZ8 t s ? s gM sIBR s jB JZ }BI ? s8BR { t ? sIBR 7Zh{$ t }s s s{sAs {Bt js %$Is I Zts } RBts tB 8sj 7 ? I tB8$ts Zts {s s P A $j }B js {$ZIsI _s s {B8} tI I PB 8s {Zsj$ s $%s {? B8B R P { ? Zs js {s s }BI 8BR Z $j$9s Zt 8BI jB 8 {? st${B R t{$jjB 7Z}Bt s8BR Zts } RBts B Zt st$8sj JZ {B s % jB{$IsI {BtR st 7$ tB t 8BR t {Z t s j sAs`B t { Rs $B }s s % t{ js R$R t{$s I j s$ Zts % 9 R ? s t 8B%$8$ t B tB Ys{ Psj s sj$9s sAs`B }s s JZ RZ {Z }B R 8st t s t 8B%$8$ t B _ B {ZstIB Zts }$ ts B Zts }s s t s t {Bt s{ B {Bt j RZ jB JZ Is t }BRB 8B8 t ? st s8 t 8$ t sR JZ j R B I j {Z }B {Bt $tZs 8B%$? tIBR Ys{$s sI jst et j 8B8 t B t JZ js }$ ts R j %st s RZj s s{ j sIs }B jBR 8? ZR{ZjBR {B R}BtI$ t R }s s R Z$ j 8B%$8$ t B sR D ]ZstIB js }$ ts jB sI jst s t Bt{ R R P tsIs }B B BR I j {Z }B wgk tB JZ Is R s ? 8? ZR{ZjBR JZ js %Z j% t s R$ Zs tZ %s8 t t }BRB t j RZ jB ej RPZ 9B } $t{$}sj I j {B IB R { t s t s{ j s k I Rs{ j s {Bt $tZs8 t RZR }$ tsR B }s sR Ns t ? s {$t? ${s JZ }BR t jsR }$ tsR I A$IB s RZ 8B%$8$ t B R $ Zsj sj sAs`B P { ZsIB }B jBR 8? ZR{ZjBR JZ sj$9st Zts {$ s PZ 9s 8$ t sR R {Bt s t Zts I$R st{$s I 8$tsIs V
V sj P { B jsR ts% R k stRAB IsIB R R}s{$sj R %st {ZA$ BR {Bt 8s $sj R { ? s8${BR R$R t R sj {sjB }s s } B RZ $t $B I jsR j %sIsR 8} s Z sR } BIZ{$IsR }B j tB 8 {sjB t sIB }B js R$R t{$s I j s$ {ZstIB s s%$ Rst js s 8? BRP s R et js {$ t _ I$IBR t j R}s{$B >NBR $t 7}s{ d MH j }js $jjB %Bjst JZ Ys I {BtIZ{$ s js Ps8$j$s iBA$tRBt s jBR {Btht R I j Zt$% RB R Ysjjs % R $IB I Zts {s {sRs - $B {Zks PZt{$? Bt }s { R js I 8$t$8$9s R P { B eRs 8$R8s P ${{$? Bt {Bt j s$ R js {sZRst I js s}s ${$? Bt I jsR R jjsR PZ s{ R t j {$ jBU 8$t? ZR{ZjsR }s ? {ZjsR I }Bj%B $t }jst s $B JZ jj st s JZ 8s R st R I sj{st9s js RZ} h{$ R B t? stIBR %$R$Aj R t j {$ jB tB{ Z tB
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
d1n
3$ n 1 3jsRY j j? s8}s B YZ8stB Zt RZ} Y? B 8? sR ? s}$IB JZ RZ } B}$s RB8A s ]s j }ZAj${$ s $B I js } j? {Zjs qY 3jsRY >d (H
© Los autores, 2001; © Edicions UPC, 2001.
d1;
* $t Bt s e$tR $t
}s $ I R RZj sIB }Z I I 8$ts R {? B8B I } tI js % jB{$IsI I Zt st$8sj {Bt RZ s8sK tB sR s {B Is }s s jjB sj {B8B ks %$8BR t j {s}? ZjB d JZ js PZ 9s ` {$Is }B jBR 8? ZR{ZjBR R } B}B {$Btsj s RZ R {{$? Bt k }B st B sj {ZsI sIB I j s8sK tB 8$ t sR JZ js 8sRs I jsR }$ tsR R } B}B {$Btsj sj {ZAB I j 8$R8B 7 t{Z t s sR? JZ js % jB{$IsI I j st$8sj R $tI } tI$ t I j s8sK tB eR RZj sIB R %? sj$IB }s s js {s s I st$8sj R {ZsI ? Z} IBR 7 ? Zt R 8BI jB 5JZ? I$R K tB I A ? s t Zt st$8sj }s s R Zt AZ t % T jB{$R s2 eR t { Rs $B JZ }BR s ZtsR }s sR sjs sIsR }s s sZ8 t s js I$R st{$s JZ }Z I {Bt s R j 8? ZR{ZjB s js % 9 JZ js 8sRs 8ZR{Zjs I jsR 8$R8sR R % s IZ{$Is sj 8? t$8B R$ ZstIB }B ` 8}jB jBR 8? ZR{ZjBR I jsR }s sR I t B I j {Z }B { t sj I j st$8sj I 8st s JZ tB R 8Z %st {ZstIB sJZ jjBR jB Ys{ t NsR }s sR I A t R }B st B j$ sR k I j sIsR eR B {Bt{Z Is s9BtsAj 8 t A$ t {Bt js PB 8s I jBR stI R {B IB R I j $tB st$8sj {B8B j Z }s IB j {sAsjjB B j {$ %B et {s8A$B jBR stI R P j$tBR {B8B jBR j Bt R k jBR $ R }BR t }s sR Z RsR sIs} sIsR sj R$R 8s JZ Z $j$9st }s s {s9s U Rsj st }B RB } Rs RBA js } Rs }s s jB {Zsj t { R$ st Zts s{ j s{$? Bt $t${$sj stI ks JZ tB RBt st ? s}$IBR {B8B }s s s s}s js {B $ tIB V Psj s I js % jB{$IsI I 3jsRY 5{Z? sj R js 8 `B R s $s }s s YZ$ I R BR I } IsIB R2 et js Rs s I tB% jsR RBA j s% t Z B }jst s $B FBYt ]s $t${$sIs {Bt =ts } $t{ Rs I s >_ $t{ RR BP s R d d1H js Pst sR? s I eI s i${ Z BZ YR }BAj? B j }jst s s {Bt ZtBR 8BtR ZBR I } IsIB R $ st RU jBR Ast YR Vj $ Zsj JZ 8Z{YBR B BR R{ $ B R k Z$Bt$R sR I j ? t B 8? sR } B{Z}sIBR }B } R t s s YB $Aj R 8BtR ZBR k - s R R I PB 8sR -? B ${sR JZ }B % {? B8B R BR t{s`st t Zt I 8$tsIB {BR$R 8s Z BZ YR I `? B I jsIB Zt sR} { B st j 8 t sj {B8B j I } B}B {$Bts s RBR 8BtR ZBR 8s {$stBR st$8sj R Y A? %B BR {Bt jBR JZ }BI sj$8 t s R VZtJZ JZ$9? sR js $t t{$? Bt I j tB% j$R s s t s RBR R R R$ 8} s js R} s I $t{sZ sR } RsR YZ8stsR 3? 8$tsR 8 `B 7$t t s s stsj$9s jBR sR} { BR A$Bj? B ${BR I jBR }BR$Aj R $}BR k R{ ts $BR I %$Is - s R }BI 8BR %sjB s s js jZ9 I jsR {Bt{jZR$Bt R - s? IsR I j 8BI jB RBA js {s s JZ? }BR$A$j$IsI R tI ? s Zt R YZ8stB I YZ$ I sj R { $s Z sR 7Z}Bt s8BR JZ ZtB I R BR 8BtR ZBR I PB 8s YZ8stB$I } R$ Z s Zts ? {Bjs 7$ t j $t t B I YZ$Is js {Y${s {B }B Zt tB YB $9Bt sj j 8BtR ZB 8s {$stB s{sAs ? s s AZ t R Z B I? stIBj sj{st{ et {s8A$B tI ? s 8? sR B}{$Bt R R$ R{s}s {B $ tIB }B Zts {Z R s z ? s8BRjB _s s RZA$ }B Zt }jstB $t{j$tsIB R s t { R$ s % t{ js s s{{$? Bt s%$ s B $s j } RB wR$t t t {Z t s j B9s8$ t BD Ns t ? }B Zt$IsI I $ 8}B B }B t{$s t { Rs $s }s s RZA$ I } tI I js 8sRs I j {Z }B wk I js s% IsI } B R s R js 8$R8s }s s s8ABR {B IB RU } R Z$IB k } R Z$IBD k I js % jB{$IsI s js JZ R sR{$ tI _B B B jsIB js }B t{$s I Rs BjjsIs }B jBR 8? ZR{ZjBR I } tI I RZ R {{$? Bt stR% Rsj k R }B st B } B}B {$Btsj sj {ZsI sIB I j s8sK tB ]B8}s stIB jsR -} R$Bt R I s8AsR }B t{$sR RZj s R t{$jjB I IZ{$ JZ js % jB{$IsI R $t% Rs8 t } B}B {$Btsj sj s8sK tB eR B R$ t$h{s JZ }s s st$8sj R I PB 8s R 8 `st {Zst B 8? sR stI R s j s8sK tB 8? sR } JZ K ts R ? s js % jB{$IsI JZ }Z I t I Rs Bjjs t RZA$Is _B st B js Y B? ts tI ? s 8? sR }BR$A$j$IsI R I }BI I RYs{ R I j P B9 8BtR ZB RZA$ tIB }B Zts } tI$ t
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
@ N
? sR I } $Rs 8? sR I } $Rs =t {B $IB }B js R{sjs I jsR % jB{$IsI R }Z I skZIs tBR s %sjB s js YsA$j$IsI I R j? s8}s B YZ8stB JZ R 3jsRY V js % jB{$IsI I }sR B ZtBR x ,8>Y Zts } RBts }Z I {B Zts 8st9sts I {sRsR I Zts {$ZIsI t Zt 8$tZ B s} B-$8sIs8 t =t {B IB I {$ t 8 BR j$RBR R {s}s9 I I R}js9s R d( 8 {sIs R ZtIB % jB{$IsI JZ } R t s nE ,8>Y sZtJZ tB }BI ? s 8st t R s % jB{$IsI 8? sR sjj? s I ZtBR { t ts R I 8 BR 3jsRY }ZjT % $9s ? s j ? {B I I j 8ZtIB I {$ t 8 BR j$RBR }Z R jB s ? s Zts $8} tRsAj 8s {s I g( ; R ! jB JZ R jB 8$R8B t j $ 8}B t JZ j }jZR8s JZ$R s YZ8stB I jBR {$ t 8 BR {B ? s R s I$R st{$s tZ R B RZ} Y? B R s ? s ks s 1 x ,8 , ,
_B B B jsIB 3jsRY tB R I R}js9s IstIB stI R Rsj BR s } Rs I JZ s{$sR s RZ st % jB{$IsI }BI ? s {BtR Z$ s8A$? t ? {B IR $t$8s $tsAj R t jsR 8BIsj$IsI R I Rsj B I sj Z s n R$8s8 t RZR }$ tsR et {B8}s s{$? Bt {Bt Zt s j s k I jBt $ ZI ]B I R}js9stIB s}$I? JZ Is I j B I t I x }sRBR }B R ZtIB jsR }$ tsR I 3jsRY Is ? st d1x }sRBR t j 8$R8B $ 8}B w}s s Zts 8$R8s js Z s I }sRBD q sR R {? sj{ZjB j 8 t sj s ZtB R j B{Z t {Bt Ps{$j$IsI sj ZtsR {Z R $Bt R 57 R$ t jsR }$ tsR2 5i R$R $ ? st RZR s ${Zjs{$Bt R s8sK ts 8B%$j$IsI2 O s8A$? t Zts ? s}$Is R}Z R sU g%sj I s{Z IB R Zt RZ} Y? B $ t sR 3jsRY $ t Ps8s A$ t stsIs I {s8} ? Bt I {s sR t jBR RZ} Y? B R B BR j I$R}Z st RZ BtB {ZstIB I jB JZ R s s R I 8B% R s s%? R I B B 8 I$B qsj R j {sRB I Zt {Bt 8}B ? st B RZkB Ws8B j } ? t{$} RZA8s $tB JZ 8 ? s t j 8ZtIB I j {? B8${ Ys{$s d n <$`B I Zts } $t{ Rs I j j tIs $B $tB RZ8 $IB I js V j? st $Is k I Zt {s}$ ? st I As {B R Zt R sthA$B JZ }Z I %$%$ st B PZ s {B8B I t B I j s Zs w j } B s Bt$R s I j hj8 Gs bB jI >Gs bB jI d xH k js RBj$ s $s { $s Z s JZ 8B s t js Ns Zts W s I js } j? {Zjs Ns 8Z` k j 8BtR ZB >qY ] s Z P B8 Y js{, Ns BBt B d x;H RBt s8A$? t B BR {BtB{$IBR R R sthA$BR I js h{{$? BtD Ns 8 9{Bjst9s I s9sR j IB ? I Zts PZ 9s RBA YZ8sts k sI 8? sR I ZtsR } JZ K tsR sj$ sR t jBR BA$jjBR JZ gj } 8$ t %Bjs et RZ8s R RZ} Y? B R I R}js9s }B $ s 8s B s$ {B8B JZ$ t tB JZ$ js {BRs sZtJZ R t j j? JZ$IB j 8 t B IBtI 8 `B R I R t%Z j% et RZ} Y? B R ABts{YBt R k A$ t$t t{$BtsIBR Ws8B I R s{s }B RZ RBA A$s B ZjjB k Zt tPsIB } 8st t {s ? s{ JZ j s{s s js t 8$R sI I BIB j 8ZtIB Ns ts s{$? Bt } 8$ JZ j YB8A }Z Is I R}js9s R }B Zt 8 I$B s{ZBRB 7$t 8As B {ZstIB R tsIs R s%st9s s s%? R I Zt 4Z$IB JZ B}Bt Zts R$R t{$s 8? sR stI JZ j s$ sj s%st{ VZtJZ tBR }s 9{s JZ R %s 8Zk I } $Rs {ZstIB R tsIs t sj$IsI ZtB R 8Z % s Zts % jB{$IsI JZ t j 8 `B I jBR {sRBR w}jZR8s {s 8ZtI$sj I jBR {$ t 8 BR sR I 1 8 R R I {$ ZtBR R{sRBR ,8 Y =ts % jB{$IsI sj B RZ} $B j$A RD R I }B{B 8? b b
=t 8BI jB R$8}j AsRsIB t j 8B%$8$ t B I } Bk { $j R } 8$ js{$Bts js sj Z s k js I$R st{$s YB $9Bt sj B sj{st{ 8? s-$8sR JZ }Z I sj{st9s Zt st$8sj {Bt js % jB{$IsI JZ jj %s t j 8B8 t B I j Rsj B $ t sR JZ Zt s j s JZ Rsj sR {Bt Zts % jB{$IsI I d( 8bR k {Bt Zts $t{j$ts{$? Bt I ;x0 {Bt js YB $9Bt sj }BI ? s sj$9s Zt Rsj B I d( 8 I jBt $ ZI jj stIB s Zts sj Z s I 1, x 8 3jsRY JZ R 8Z % s Zts % jB{$IsI 1x % { R RZ} $B $ ? s s }s s {js B R ? s 8Z{YB 8? sR j `BRU s 8? sR I E ,8 I I$R st{$s k s d, x ,8 I sj Z s gWB R ? s tsIs 8sj n
© Los autores, 2001; © Edicions UPC, 2001.
@ -
* $t Bt s e$tR $t
s js I }sR B 3? ` tR {B8B t jsR } Z AsR I {B8} ${$? Bt I ts s{$? Bt j `Z 9 JZ R 8Z % }B j AB I I js }$R{$ts R$ Z R$t t$t Zts I$h{Zj sI sj tsIsIB 8? sR % jB9 $ t sR JZ jBR YZ8stBR Yst I Rs BjjsIB ZtBR }B{BR R $jBR ts s B $BR jsR ? {t${sR 8}j sIsR }B jBR st$8sj R s{Z? s ${BR RBt 8Zk %s $sIsR V I$P t{$s I stIs B %Bjs }s s tsIs t j s Zs {ZsjJZ$ {BRs R$ % Ws8B sj $ Zsj JZ B BR $jZR R tsIsIB R I js h{{$? Bt {B8B j } B s Bt$R s I js } j? {Zjs tsIs 4 -$BtstIB s $As k sAs`B RZ {BjZ8ts % A sj eR s ? {t${s R js JZ 8}j st jBR stI R k ? s}$IBR tsIsIB R I j 8ZtIB 8s $tB {B8B RBt jBR I jht R k jsR Asjj tsR eR BR 8s8? P BR 8s $tBR }Z I t 8st t % jB{$IsI R JZ RBA }sRst jBR d( 8>R p s{$sR s jjB jBR I jht R }B ` 8}jB }Z I t Rsj s s Zts sj Z s I YsR s x 8 t % ${sj
Gs bB jI
s $t
7$ ZtB tB R 3jsRY k I R s 8B% R 8? sR I } $Rs R$ 8} }Z I {Z $ s sj Zts 8? sJZ$ts JZ } 8$ s sZ8 t s js }B t{$s I jBR 8? ZR{ZjBR =t {${j$R s }Z I I Rs Bjjs Zts % jB{$IsI 8$R8B R$ tBR I Rj$9s8BR t % 9 I {B }BI 8BR $t{ 8 t s 8? s-$8s I ZtBR x ,8>Y VR? js % jB{$IsI k jj s YsR s jBR x( ,8>Y t{$8s I ZtBR }s $t R RBA Y$ jB B RZ} s jBR 1(( ,8>Y {Bt js } ? s{ ${s I j RJZ? 7$t {Z $ s B BR 8 {st$R8BR I } B}ZjR$? Bt JZ tB R st jBR JZ } B{ I t I j RPZ 9B 8ZR{Zjs }s { JZ ? R s R ? s js % jB{$IsI 8? s-$8s s js JZ }BI 8BR I R}js9s tBR }B js RZ} h{$ R et {Zst B s jBR st$8sj R -$R js tI t{$s ? Bt s s {BtR$I s JZ jBR 8? sR stI R R 8Z % t 8? sR j t s8 t JZ jBR } JZ K tBR ]B8B R K tsjs yRss{ VR$8B% $t4Zk }BR$Aj 8 t js $I s I j $ 8}B JZ j st$8sj $t%$ t {B Zts I$R st{$s {B8}s sIB {Bt RZ s8sK tB ] 8BR sR? JZ Zts s I$jjs JZ R I R}js9s {B $ tIB R 8Z % 8? sR I } $Rs JZ Zt j Pst JZ }s { {s8$ts j t s8 t WsIs 8? sR j `BR I js sj$IsIU Zt j Pst }Z I 8B% R s ZtBR s}$IB {B8B Zt % jB{$R s YZ8stB k 8? sR I } $Rs JZ js $tJZ$ s s I$jjs q tI 8BR ;( ,8>Y st ? s8A$? t s R $8s I PB 8s ? Bt s js % jB{$IsI I sJZ jjBR st$8sj R JZ $ t t Zt 8 {st$R8B I jB{B8B{$? Bt I$P t I j tZ R B =t ` 8}jB R ? s j I jsR R }$ t R js 8? sR ? s}$Is I JZ I t { R$ s jB }BI ? s8BR YZ$ jsR {Z? sj R }Z I {B8B 8Z{YB 8B% R s ZtBR 1x ,8>Y VR? {B $ tIB R$t 8Z{YBR } BAj 8sR =t {$ 8}$? R } R s {Bt s {Bt js skZIs I BIsR RZR }s sR R 8Z % RBjs8 t 8 I$B 8 B }B R ZtIB w8 tBR I 1 ,8>YD NBR k R I js % jB{$IsI I j $tB st$8sj RBtU t $ s j Z }s IB JZ sj{st9s jBR d(( ,8>Y t j 8s j } 9 % js Zts %s $ IsI I } 9 R}sIs JZ tsIs s dd( ,8>Y t j s$ k t %Z jB j$A j % t{ `B {s}s9 I %Bjs s d ( ,8>Y k j Ysj{? Bt JZ t %Z jB t }${sIB s} B% {YstIB js s% IsI sj{st9s sR j %sIs s js JZ }Z I I R}js9s R Zt R %$%B R$t js jBR nx( ,8>Y eR s R js % jB{$IsI 8? skZIs I t$t ? Zt 8B B i tZt{$stIB sj {Bt Bj }BI 8BR sj{st9s R s % jB{$IsI R$t 8? sR JZ s B`s tBR I RI Zt st sR{s{$ jBR g_ B s JZ? } {$B V 8 tZIB tBR P $8BR s js ? }B{s s{ Zsj {B8B js s I js % jB{$IsI O P { $%s8 t tZt{s {B8B sYB s js % jB{$IsI I j stR}B k I jsR {B8Zt${s{$Bt R YsA? s { {$IB s Zt $ 8B st R} { s{Zjs et j s ?8A$ B I jsR % jB{$IsI R I I R}js9s8$ t B tB R YsR s htsj R I j R$ jB y JZ {Bt js s}s ${$? Bt I j t k I j sZ B8? B%$j js YZ8st$IsI sj{st9s jBR d(( ,8>Y O jjB s } Rs {B8B R$ 8} RZ{ I {Bt j } B RB {tBj? B ${B I {$ sR ${ t{$sRU {ZstIB R R sAst {BtR Zk tIB jsR } $8 sR jB{B8B B sR s %s}B wYs{$s dMM(D sj ZtBR { ? ${BR sR Z sAst JZ js sRh-$s R} sAs s BIBR sJZ jjBR JZ sj{st9s st gjs R}st BRs % jB{$IsI I x( ,8>Y et j stR{Z RB I Zts t s{$? Bt R RZ} s j j? 8$ I jBR d!((( ,8>Y {Bt js s}s ${$? Bt I jBR
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
d1
{s s{Bj B Z s R {$ 8}$? R YB8A w}sR BD tsIsIB R }$ t {B IB I jP? t }s $tsIB As {B I }sRs` BR RZA8s $tB s ? B8${B RZ8 $IB {${j$R s Z }s IB } 9 % js %$ t B wYZ s{? stD jst{Ys 8B B s % t{ `B t I %s}B RJZ$sIB sZ B8? B%$j Ysj{? Bt w%Z jB t }${sIBD Y j${? B} B t j? { ${B %$ t B w B tsIBD t 8BtB s? j I j %$ s{$? Bt 8s t? ${s sZ B8? B%$j I {s sR s%$? Bt I Y? j${ 3jsRY wRZ} Y? B D sZ B8? B%$j w8B B {BY D RBt$IB t j s$ q$ s w B s{$? Bt t j {ZsIB D s%$? Bt I s{{$? Bt {BY {Bt% t{$Btsj q$ s w% jB{$IsI B A$ sjD {BY < j$BR 7Bj w R} { B { t B sj? s{ ${BD jZ9
z jB{$IsI w ,8>YD (, (x (, n 1 x M 1x nE nE x( ( ( x d(( dd( k d1( dxx d ( dM( 1(( n(( nx( n ( nM( ;M( xdx E x MM( (( d3d ( d3d x d3EM( n3xMx ;(3n(( d( 31M( 1;(3((( 13((( d, (M d(
R ${sR I sj ZtBR R R %$%BR 8? sJZ$tsR k BA` BR I j Zt$% RB { t j$t qsAjs n d z jB{$IsI R {s s{ ?
© Los autores, 2001; © Edicions UPC, 2001.
d1M
* $t Bt s e$tR $t
s%$Bt R k j {BtR {Z t IB8$t$B I j s$ RBA }sRstIB js 8? ${s As s I j RBt$IB wd!d x ,8>Y B s{Y dD ej } B RB RZj s s }s $ I sJZ? % $ $tBRB V }s $ I d x( k t st RBjB Zts I? {sIs R sj{st9s js {B s I jBR d(!((( ,8>Y {Bt j I Rs BjjB I jBR s%$Bt R RZ} R? Bt${BR k {Bt js s}s ${$? Bt I jBR {BY R R}s{$sj R wd E(D R s{sAst RZ} stIB jBR d((!((( ,8>Y ]js B R ? s JZ R sR tB 8 R % jB{$IsI R $ t t $t ? R R? BjB t j s ?8A$ B I jBR %$s` R R}s{$sj R _s s I R}js9s tBR }B js RZ} h{$ R R RZh{$ t js AstIs I jBR d (((Td( ((( ,8>Y =ts I jsR RBjZ{$Bt R 8? sR $t tZsR } B}Z R sR }s s R $}B I %$s` R js t{Bt s8BR t j hj8 iB{, >qY VI% t Z R BP Y iB{, d dH ej } B s Bt$R s I 8st s s{{$I t sj t s t }BR R$? Bt I Zts 8B{Y$jsT{BY s s{{$? Bt -} $8 t sj JZ } 8$ %Bjs s Zt YB8A VK ts ?Istj Zt {sR{B JZ s{ ? Zs {B8B $8? Bt k g}s s{YBJZ R k ks t 8BR s B B RZ} Y? B j YB8A T{BY } }s sIB }s s js s{{$? Bt NBR 8sj%sIBR I Z tB t R {sRB jBR ts9$R w t Zts {js s P t{$s k YB8 ts` s jBR R $sj R I jBR sK tBR d ;(D $t t s ? st Ys{ R }B BIBR jBR 8 I$BR {Bt j s $jZ $B }s s RZR } B}$BR ht R Ns } j? {Zjs R ? s $tR}$ sIs t j hj8 $t BP Y iB{, t >d ; H IBtI j Y? B % R $IB I {BY R$ Z t R {sRB js }$R s I Zt 8sj%sIB t8sR{s sIB j * zZj{st NsR }$ Z sR %BjsIB sR I j } B s Bt$R s jsR {BtR$ Z R$t 8? sR JZ $ s jBR R AB Bt R I {Bt Bj I RZ s` U j I % jB{$IsI w{Bt IBR }BR${$Bt RU s $As Bt }s s k sAs`BD j I {Bt Bj } B}$s8 t w{Bt jsR }BR${$Bt RU t{ tI$IB k s}s sIBD k j AB ? 8B% R {Bt 8skB B 8 tB s}$I 9 g=t }$jB s` I Zts {js $IsI k R t{$jj 9 - sB I$ts $sR *$ tB {B8} $IB I 3jsRY iB{, I A sP Bt s $ttZ8 sAj R } BAj 8sR R$ I R s IB s I %$RBR I % BR$8$j$ ZI s RZ } B}$B } RBts` Vj $ Zsj JZ RZ {Bj s I A Ys{ P t sj } BAj 8s I jsR s{ j s{$Bt R k I Rs{ j s{$Bt R {ZstIB I R s }s $ tIB I j }BRB sj{st9s ZjB 1D VI 8? sR I js P ${{$? Bt {Bt j Zts {$ s % jB{$IsI B I$R8$tZ$ ? R s }s s s $9s w]s}? s$ JZ I A R j %sIs wsZtJZ tB R R} {$h{s s JZ? % jB{$IsI %Z js {sA RZ}Bt JZ jB Ys{ s js I Zt {BY s s{{$? Bt IBR }s s R -s{ BR }Z R I R s Z$Rs R ? s {BtR $ Z$IB j s $jZ $B sIBRsIB s RZ R}sjIsD R ? s j } BAj 8s I j {B8AZR $Aj Z ts }s I j {Bt t$IB I jBR {BY R {Bt% t{$Btsj R R ? s B{Z}sIB }B j {B8AZR $Aj ]ZstIB ? R R JZ 8s t s jBR sR R JZ Zts % 9 k { sIBR Ys{$s s ? sR $8}ZjRst sj {BY 7 s s I Zts s}j${s{$? Bt } ? s{ ${s I js {BtR %s{$? Bt I js {st $IsI I 8B%$8$ t B k I js j k I s{{$? Bt k s{{$? Bt ej {BY sR{$ tI } B}ZjRsIB }B jBR sR R I R{s} WB }s { JZ js 8B{Y$js I j YB8A {BY }B 8Zk -} $8 t sj JZ R s {Bt t s j {B8AZR $Aj RZh{$ t {B8B }s s JZ t {sRB I RBA %$%$ s jsR stI R s{ j s{$Bt R k I Rs{ j s{$Bt R s JZ R s ? s RB8 $IB j RZ} Y? B }Z Is %Bjs stI R I$R st{$sR eR AsR st } BAsAj JZ I As R s {Bt $tZs8 t }BR stIB RZ I }? BR$ B {Bt js {BtR {Z t }? I$Is I sZ BtB8? s I %Z jB _BI ? s sIZ{$ R JZ sj % 9 j s $jZ $B PZt{$Bts $8$ stIB js PB 8s JZ $ t t I } B}ZjRs R st$8sj R {B8B j }Zj}B B j {sjs8s eR BR st$8sj R 8s $tBR -}ZjRst {Bt Zts st PZ 9s j s Zs {B $Is }B RZR {Z }BR I R 8} K tstIB ? R s j 8$R8B }s} j JZ jBR sR R I js {B8AZR $? Bt }s s Zt {BY s s{{$? BtU j s Zs -} j$Is ` { RBA jjBR Zts PZ 9s $ Zsj k I R t $IB B}Z R B JZ jBR } B}ZjRs Ys{$s sI jst 7$t 8As B R s 8BIsj$IsI I } B}ZjR$? Bt s s{{$? Bt R$t {B8AZR $Aj PZt{$Bts A$ t t Zt 8 I$B {B8B j s Zs IBtI I A$IB s JZ js I tR$IsI R 8Z{YB 8skB JZ js I j s$ AsR s Zts } JZ K ts RZ} h{$ {Bj { B s }s s -}ZjRs {Bt }BR $B $IsI Zts 8sRs I 4Z$IB RZh{$ t
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
@
3$ n n _s s { s Zt RZ} Y? B {sR B AsR s 8AZ $ s Zt $tI$%$IZB I t B I Zt s` jB 8? sR R sPsjs $B }BR$Aj JZ$}s jB {Bt sj Zts JZ B s s 8s k t%$s jB s PZR $ s s st R R jB{sj R B I j R}s{$B - $B ! s? Zt 8? sR P? s{$jU RZR $ Z$ j RB8A B I {BbABk }B Zt {sR{B R}s{$sj I YB`sjs s jBR }st sjBt R %sJZ BR k j {Ysj {B }B Zt s}s s BRB s` {s8A$s j {sAsjjB }B js ts% R}s{$sj k s js }$R Bjs s{B}js j Zt 8AZIB 8 ? sj${B g s8}B{B R {BRs I $ttB%s VJZ? $ t t ZtB I jBR }BR$Aj R RZj sIBRU ]B88stIB ]BIk 7,k B I j $}B I s RYsjj BP Y =t$% R } B s Bt$R s I js R $ I j %$R$? Bt I j 8$R8B tB8A >d xnH 7Z} Y? jBR JZ R$t s` tB RBt tsIs jsR j$8$ s{$Bt R I } RZ}Z R B RBjs8 t j } 8$ t Z $j$9s j s` I YB8A {BY I RZ {Bj s iB{, t 3? ` tR t jB P? s{$j JZ }s { RZ 8st `B {Bt R? BjB R AB Bt R I {Bt Bj O }B {$ B 5}s s JZ? JZ$ Zts {s}s R$ RZR s% t Z sR RZ{ I t }B jB {B8? Zt t 8ZtIBR R$t s$ 2
© Los autores, 2001; © Edicions UPC, 2001.
dn(
* $t Bt s e$tR $t * j YB8A 8Z {$? js B sj YB8A s sK ts
n 1
Z{ Gskt 8? sR {BtB{$IB {B8B s 8st R Zt 8$jjBts $B ` {Z $%B {Bt Zts IBAj } RBtsT j$IsI $ t sR s}s t s I$ $ $ RZR t B{$BR t js RB8A s Z $j$9s RZR }BR$A$j$IsI R {Bt? B8${sR }s s }Bt R sj R %${$B I js `ZR ${$s k Ys{ P t s js j $? Bt I 8sj%sIBR k %$jjstBR JZ {s8}st }B pB Ys8 ]$ k ]ZstIB t j {$ jB I js {$ZIsI R } Bk { s j R? 8ABjB I j 8Z {$? js B RsA JZ js {$ZIsI j t { R$ s 7 tPZtIs t RZ s` k gYsjs s I RPs{ t Z BR 7Z R? 8ABjB R j 8Z {$? js B } B tB $ t tsIs JZ % {Bt R BR st$8sj RU R R$8}j 8 t Zt YZ8stB I$RP s9sIB Ns {s B ? s I RZ} Y? B js sj{st9s s{$sR sj s R tsj I s $jZ $BR JZ Z $j$9s }s s tP t s R sj 8sj 7Bt jBR {BtB{$IBR As s}s s BR ; s 8st tB $ t RZ} }BI R {B8B 3jsRY 7}$I 8st B j } B}$B 7Z} 8st k R Zt } RBts` 8? sR YZ8stB 8? sR { {stB s js sj$IsI JZ s js h{{$? Bt 7 s s I Zt `ZR ${$ B JZ s{ ? Zs s 8 tZIB sj 8s t I js j k jB JZ j B{sR$Bts tB }B{BR JZ A sI BR I {sA 9s {Bt RZR j ? $8BR I P tRB R js }Bj${? s I pB Ys8 ZR{ZjsIB YsA$j$IBRB k Rsj s ? t 8AZ $IB t Zt { K t$IB s` t B }s s sAs`s sj R s js {Bt -$? Bt {Bt j 8Z {$? js B2D jj s IBtI tsI$ s8}s B I js BR{Z $IsI I js tB{Y w5 R ? }Z I jj s k sI 8? sR s $ 8}B =t sR B } {Zj$s I s 8st R JZ R? BjB s{ ? Zs t pB Ys8 ]$ k eR B Ys{ } tRs JZ IsIs js I j$t{Z t{$s -$R t t js {$ZIsI tB Is sAsR B ! A$ t JZ tB j ZR s %$s`s sZtJZ t Bt{ R 5}s s JZ? t { R$ s Zt sZ B8? B%$j st R} { s{Zjs 2 ej } RB I js `ZR ${$s I A R I 8sR$sIB stI }s s Zt RZ} Y? B RBjB sR? JZ 8Zk } Bt B t js { BtBjB ? s I j } RBts` jBR Z$Bt$R sR j } B}B {$Bts ? st Zt skZIst U j {Y${B 8s s%$jjsR iBA$t Os t 8BR PB 8sIB j Ps8BRB IZ B Pst ? sR ${B ej } RBts` I s 8st PZ { sIB }B j I$AZ`st BA st t d n k ks t d ;( I$R}BtI ? s I {? B8${ } B}$B }sRstIB A$ t } Bt B s js }st sjjs t R $sj R {B8B s 8st >d ;nH k s 8st stI iBA$t >d ; H k s js j %$R$? Bt >d EEH IBtI $t{jZRB tI ? s Zts R $ I I$AZ`BR st$8sIBR 7Bt sIs} s{$Bt R 8? sR B 8 tBR h j R s jBR {? B8${R I IBtI } B{ I jBR {Zsj R {Bt $t? Zst I$ ? stIBR _B j 8B8 t B {Zs B RBt jBR js B8 s` R sj$9sIBR RBA j } RBts` U s 8st >d M H s 8st %Z j% > s 8st i Z tR d 1H s 8st 3B % >d nH k s 8st k iBA$t > s 8st m iBA$t d H et jjBR s}s { t 8sj%sIBR I sjjs {B8B j FB, B j _$t [ Z$tB JZ jj st $t{jZRB s {j$}Rs sj } B}$B RZ} Y? B k JZ? %B{sR RZ} Y B? tsR {B8B ]s GB8st js 8Z` s B B _B$RBt y%k Ns } R t{$s I R BR R 8}$ tBR k }? hIBR 8sjY {YB R Is JZ? } tRs 57Bt ZtBR 8sjBR 8Zk AZ tBR t jB RZkB2 5! A$ t R JZ s 8st tB R {s}s9 I s{sAs tZt{s Zt sAs`B sZtJZ {Z t {Bt js $t R $8sAj skZIs I iBA$t2 ]B8B R K tsj? sAs8BR ZtsR j? t sR 8? sR s $As jBR As s}s s BR k RZR YsA$j$IsI R {$ { tR R RZ}j t {Bt YBj Z s js Psj s I }BI R I R RZ} Y? B WsIs JZ I${YB R s I }sRB tB }Z Is {BtR Z$ R s AsR I Zt t ts8$ t B sI {ZsIB zs8BR s stsj$9s s {Bt $tZs{$? Bt jsR }BR$T A$j$IsI R I R BR As s $jZ $BR s {s}s _s { R? BjB Zts {s}s JZ Is Zt {$ B {Bt s}Zt B sj % R $IB I RZ} Y? B } B sI 8? sR j R$ % }s s }jst s WB BAR st RZj s I 8sR$sIB } JZ K ts {B8B }s s RB}B s j } RB I Zt PB t$IB RZ} Y? B NsR ? }${sR sjsRTI j s Z $j$9sIsR }B jBR } s{ ${st R I j %Z jB }jst sIB $ t t Zts RZ} h{$ 8Z{YB 8skB ]Z $BRs8 t js {s}s }sRs I t js - Z s 6 ;
s
t $t j? R R$ t$h{s 8Z {$? js B
© Los autores, 2001; © Edicions UPC, 2001.
n *Â&#x201A; 7Z}Â&#x201A;Â&#x201E;8st sj YB8AÂ&#x201E;Â&#x201A; $t%$R$AjÂ&#x201A;U ? IBjBR {Bt }$Â&#x201A;R IÂ&#x201A; AsÂ&#x201E;Â&#x201E;B
dnd
3$ n ; =ts RB8AÂ&#x201E;s %$ $jst Â&#x201A; RÂ&#x201A; }Â&#x201E;BkÂ&#x201A;{ s RBAÂ&#x201E;Â&#x201A; pB Y8st ]$ k 5eR Zt YB8AÂ&#x201E;Â&#x201A;2 5eR Zt 8ZÂ&#x201E;{$? Â&#x201A;js B2 WB Â&#x201A;R s 8st 3B B Â&#x201E;s8sR IÂ&#x201A;j hj8Â&#x201A; s 8st >d M H
Š Los autores, 2001; Š Edicions UPC, 2001.
dn1
* $t Bt s e$tR $t
I js B}s s B ts R ? $Is {ZstIB s s 8st j Is }B }jst s
s R K tsj eR js PB 8s JZ js {$ZIsI I pB Ys8 $ t I {js8s js } R t{$s I j RZ} Y? B eR {B8B Zt stZt{$B {B8 {$sj R$ ZsIB t j {$ jB JZ s}s { {ZstIB R $jZ8$ts {Bt ZtBR }B t R PB{BR I RI j RZ jB i } R t s j jB B $}B I j 8Z {$? js B R jjB I $I t $IsI I j } RBts` eR I$P? {$j { s Zt I$AZ`B } {$RB t j {$ jB sZtJZ t R} { ? s{ZjBR 8ZR${sj R B }$ B ? {t${BR R {BtR$ Z t P { BR sj B }s {$IBR {B8A$tstIB }B t R Ys{ R jZ8$tBRBR w$t{jZRB skBR j? sR D {Zks jZ9 R I$R} RsIs }B j YZ8B B }Bj%B {$ {ZtIst qsj % 9 R s Zt AZ t 8? BIB }s s s8 I t s s jBR 8sj%sIBR } B RZj s ? s 8Z{YB 8? sR P { $%B k } ? s{ ${B Zt j? PBtB 8? B%$j }Z R B JZ js {B8Zt${s{$? Bt t s8ABR R t $IBR R$ 8} R RZ} $B 6
=t AZ8 st AsR st }s {$IB t {Zst B s PB 8s s jBR sj R Ns R$8$j$ ZI s{sAs sJZ? =tB tB R -}j${s {? B8B }Z I %Bj% sj jZ s I j jst9s8$ t B Zts % 9 Ys I `sIB PZ s I {B8As s ZtBR {Zst BR 8sjY {YB R =ts } B 9s 8? sR sjj? s I js P? R${s JZ {B8}s s8A$? t j R{ZIB I j ]s}$ ? st V8? ${s 6 6 s 8? B%$j ej RZ} sZ B8? B%$j I s 8st Zts 8s s%$jjs {tBj? B ${s RZ} $B sj }B}Zjs ]B{Y 3st ? sR ${B i RZj s I j BIB $t -}j${sAj }B JZ? jBR Z$Bt$R sR Yst IB sIB s R % Y? {ZjB I
s AZ8 st
} B}ZjR$? Bt s s{{$? Bt {BtI tsIB {B8B R ? s s BIs R? BjB }B js {sjj R k s% t$IsR I pB Ys8 ]$ k Vj 8s t I jsR s{ j s{$Bt R k P tsIsR s jsR JZ j IZ B Pst ? sR ${B R ? s RB8 $IB IZ st RZ }$jB s` jsR I$h{Zj sI R I js {BtIZ{{$? Bt s j %sIsR % jB{$IsI R }B js {$ZIsI RBt jsR 8$R8sR JZ jsR JZ -} $8 t s j {B IB 3jsRY {Bt j s s%st I JZ s }B{B JZ R s} $ j s{ j sIB 8? sR I js {Z t s j % Y? {ZjB }Z I I R} s I j RZ jB gk s %Bjs _B jB 8 tBR j sAj B I 8stIBR R ? s s{B I {Bt js RBhR ${sIs {tBjB ? s JZ {sA s $AZ$ s Zt sZ B8? B%$j I R sR {s s{ ? R ${sR ej t? Z8 B I AB Bt R jZ{ R }s }sI st R $tI${sIB R {Z Is sj I Zt s%$? Bt 7 R$ Z sJZ? js js tB R{ $ s I JZ j sIB I RBhR ${s{$? Bt {tBj? B ${s R } B}B {$Btsj sj t? Z8 B I jZ{ {$ sR }sjst{sR k AB Bt R I j s $jZ $B t {Z R $? Bt 3Z ZtB I jBR } $8 BR % Y? {ZjBR I js h{{$? Bt IB sIBR I j? PBtB Vj $ Zsj JZ j s` I j RZ} Y? B R Ys sIs} sIB s8A$? t s jsR tZ %sR 8BIsR k s%st{ R {tBj? B ${BR k sYB s $t{B }B s ks Zt %? I BT j? PBtB I$R}BR$ $%B JZ tB s Is 8BR t % $tR sjsIB t jsR tZ %sR t s{$Bt R I sZ B8? B%$j R Z $j$ s $BR et {s8A$B R ? s 8? sR I$P? {$j JZ B BR s{{ RB $BR I j % Y? {ZjB R st {BtR$I sIBR }B jBR PsA ${st RU }B js R$8}j } R$? Bt I Zt AB ? Bt j As 8? B%$j }Z I IZ{$ RZ st{YZ s I PB 8s sZ B8? s ${s *BR I jsR {Zs B Z IsR JZ }BR {sIs ZtB I RZR ` R tB I j % Y? {ZjB k R sI jst st k {BtR $ Zk t Zt tZ %B ` jB JZ } 8$ IZ{$ w2D j s8sK }BR$A$j$ s BIs s s%? R I jBR 8? sR R {YBR jZ s R O BIB s{B8}sK tsIB I j jst9s8$ t B I } Is9BR I j sZ B JZ }$ I t js s{{$? Bt }s I RZ {s B{ ? s =t R} { ? s{ZjB %s8BR
s st{YB WsIs - sB I$ts $B =t st{YB {B $ t RB R? I Zts st R$R t{$s t PB 8s I R jjs I R }Zt sR =t$IB s Zts {Z Is B {sAj } 8$ s tZ R B RZ} Y? B Rsj s s js 8st s I 7}$I 8st {Bt RZR js sK tsR I I$h{$B t I$h{$B q$ t s8A$? t B BR ZRBR {B8B }B ` 8}jB RBj% t s sj ZtBR I jBR } BAj 8sR s jBR JZ I A ? s Ys{ P t Zt {B IB {B8B 3jsRY }s s $ s s % jB{$IsI R j %sIsR et js } j? {Zjs s 8st }Z I % R sj As 8? B%$j YZ$ s st % jB{$IsI }B jsR {sjj R I pB Ys8 } R Z$IB }B %s $BR % Y? {ZjBR s R sIBR I 8sjY {YB R et j 8B8 t B `ZR B t JZ $t${$s js 8st$BA s I $ B t Zts {Z %s 6
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
dnn
{ sIs s 8st jst9s Zt {sAj JZ JZ Is h`sIB s{$sR sj As T st{YB t Zts Ps Bjs Ns tR$? Bt I j {sAj } B}B {$Bts js PZ 9s { t ? } s sI${$Btsj JZ j } 8$ I R{ $A$ js {Z %s 8Z{YB 8? sR I } $Rs JZ jBR % Y? {ZjBR } R Z$IB R jBR {Zsj R s{sAst R jj? stIBR {Bt s jsR Bt Zts % 9 8? sRD ]js B JZ js Z $j$IsI }s I R I jBR I$h{$BR {$ {ZtIst R wjs $t {$s t s{{$? I j 8? BIB }sRs }B I$R}Bt I Zt {sAj {Bt js R$R t{$s RZh{$ t {B8B }s s JZ s } Rs I R s RB8 $IB s PZ R s{{$Bt R tB R B8}s ]ZstIB tB R Z $j$9st BIBR R BR As s $jZ $BR } 8st { t Zs IsIBR t js As {Z %s R$ ZsIs As`B js 8stR$? Bt I Z{ Gskt T s 8st et jjs R Ysjjst s8A$? t Zt As stsj$9sIB TI T {ZsjJZ$ T{BRs k {js B Zt As B I tsIB {s}s9 I R}BtI {ZsjJZ$ {Z R $? Bt JZ R j PB 8Zj ej h j 8skB IB8B VjP I R t{s s I t jB BIB t AZ tsR {BtI${$Bt R I ZRB et js j? t s I s 8st -$R t B BR RZ} Y? B R YZ8st$9sIBR 7Bt YZ8stBR B I$ts $BR A$ t 8ZR{ZjsIBR RB R? } B JZ tB }BR t - sK tBR RZ} }BI R *B{ 7s%s ts{$IB t j {? B8${ t d nn R Zt s{sZIsjsIB {$ t ? h{B {sR$ RZ} YZ8stB t $t j$ t{$s k t PZ 9s JZ tB IZIs t {Z $ s RBhR ${sIsR s 8sR {Bt Zts {$ s AsR {$ t ? h{s {ZstIB R t { Rs $B q$ t Zt JZ$}B I {$t{B RZAB I$tsIBR R} {$sj$9sIBR t s R %s $sR w -}jBR$%BR { D k {$ t{$sR JZ AB I st jBR $t{$ BR j? 8$ R I js {$ t{$s h{{$? Bt * I${s RZ %$Is s {B8As $ {BtR}$ s{$Bt R { $8$tsj R k R j t{Z t s I %$R$ s } 8st t t 8ZtIBR $ tB BR k } I$IBR ej YB8A I BjB t j tB8A I A Bt{ {B8B sR? R j jjs8s R Zt } RBts` JZ $t4Z$ ? s t j I$R K tB wk tB R? }$jsU ]js , 7s%s k ]js , t R} { $%s8 t D {B8B } RBts` RZ} Y B${B I 7Z} 8st wsj$sR j YB8A I s{ BD JZ Ys ? s RZ s}s ${$? Bt }B{B I R}Z? R *s ? s j Rsj B s js }st sjjs {Bt js } j? {Zjs *B{ 7s%s qY st BP Bt9 >d xH ? sR Ps8BRB R 3jsRY pB IBt } RBts` JZ %$B js jZ9 t d n; k JZ Ys R$IB jj %sIB s js }st sjjs t I$P t R B{sR$Bt R w{B8B R $sj t d nE d nM k d ;( t Zts R $ I qz t d xd k t Zt B ${BR js B8 s` t d M( R$ 8} As`B j 8$R8B ? ZjBDN 7ZR s% t Z sR k I R% t Z sR t -? }jst sR {BtR $ Zk t Zt 8BI jB I jB JZ Ys IsIB t jjs8s R js B ?} s R}s{$sj wR}s{ B} sD RZA ? t B I js {$ t{$s h{{$? Bt t j JZ R t jBAst BIsR sJZ jjsR Y$R B $sR I s% t Z sR s Zt R}s{$sj R {Bt {$ BR BJZ R I B8st ${$R8B wjs Rs s I js Z s I jsR sjs-$sR R ? ` 8}jB {$ t D 3jsRY pB IBt R jsR $ t {Bt Zt Y? sA$j st s Bt$R s I 8? Zj $}j R {Z RBR j %$jjstB $t j * R}$sIsIB JZ $ t RZ R I t j }jst s Bt B N s{B8}sK tst t RZR {B ? sR }B js psjs-$s RZ $tR }s sAj s8sIs *sj V I t k Zt BR{Z B {$ t ? h{B j * s ,B% Ns s{{$? Bt }$Ist $ t jZ s t t B tBR IBtI R 8 9{jst j 8 t BR PZ Z ? R ${BR {B8B skBR I js 8Z k ts% R R}s{$sj R {Bt B BR s {s${BR {B8B I$tBRsZ $BR `Zt jsR k R}sIsR VZtJZ A$ t R % IsI JZ R tB s Zts {$ s {Bt t{$? Bt t j ZRB I j 8 t BR st I$R}s R V I$P t{$s I jsR Y$R B $sR I Z BZ YR IBtI } $8s js s% t Z s }B js s% t Z s jsR } $} {$sR t JZ R % t%Z j B 3jsRY pB IBt $ t t Zt j$ B BJZ I }jsZR$A$j$IsI WB BAR st jsR s R k }BI R I j I$sA? Bj${B $t js Pst sR? s I RsPB sIs t js I {B s{$? Bt }jst s $s j ZRB I
]B8B s 9s {sA {$ s js } j? {Zjs 3j RY pB IBt >d ;H Zts I j$ st I$% $Is k AZ j R{s }s BI$s I jsR } $} {$sR I R } RBts` IBtI BIB $ t {js sR {BttB s{$Bt R k P t{$sR R -Zsj RU jsR ts% R R}s{$sj R }BR t }B ` 8}jB PB 8sR $t JZ? %B{s8 t P? sj${sR k Zt $ st } t RsZ $ZR {s8}s s RZR st{YsR O {B8B s Z8 t BU js s8 ts9s I j 8} sIB Gst R K tB I j }jst s _B tB JZ I R s sIZ K ts R I js q$ s s s{? stIBjs {Bt Zt skB g ? B ${B N
© Los autores, 2001; © Edicions UPC, 2001.
dn;
* $t Bt s e$tR $t
js s% IsI { {Bt $ t t B R I AZj B JZ ZtB I A sRZ8$ I st 8stB
ej R $jB t B8? st ${B k As B{B I 3jsRY pB IBt R {BtR$I sIB }B sj ZtBR { ? ${BR {B8B Zts R}Z R s s js P ? s {tBjB ? s } R t t js psjs-$s { sIB t d 1 w
Z{, iB R Z{, iB R $t Y 1x Y ] t Z k
Zt $jZR st { RB {B8B JZ$`B I D Z{, R Zt t$ t I jsR PZ 9sR
s? sR tB s8 ${stsR JZ $tsI% $Is8 t RZj s stR}B sIB x(( sK tBR Ys{$s j PZ Z B et js R $ I j %$R$? Bt Z{, R Zt sR BtsZ s JZ I R}$ s sR x(( sK tBR I Y$A ts{$? Bt
} B js R$ Zs{$? Bt I }s $Is R js 8$R8sU t R 8ZtIB PZ Z B jBR R R I A t Ys{ P t s jsR YB IsR I 8sj%sIBR - s R R JZ {s8}st s RZR st{YsR }B j }jst s V{B8}sK tsIB }B RZ ts tB%$s G$j8s * $t j AZ tB I Z{, R }sRs js %$Is jZ{YstIB }B $ s
}B 8s B }B j R}s{$B {Bt s RZ 8B sj t 8$ B $jj st NBR $t I$ t R I js B ?} s R}s{$sj R ? st R %$IBR k R {Z s BIBR jBR ? B}${BR {BtB{$IBRU st $ s% IsI }$R BjsR I Ns }B}Zjs $IsI
skBR I R$t sIB R ts% R R$I sj R {$ZIsI R } B $IsR }B {? Z}ZjsR { I
Z{, iB R R $tP $B s js I 3jsRY pB IBt sZtJZ j } RBts` B9s ? s {B8B ? R I
R $sj R >d n H R $ R I j %$R$? Bt >d x( d H k YsR s I Zts } j? {Zjs >d H
]B8B {Bt s}Zt B s R BR Y? B R 8sR{Zj$tBR t 8BR s Zts s ? }${s RZ} Y B ? tsU
s As jjs
eR Zt RZ} Y? B s8B sj R -Zsj8 t $tRs{$sAj k {Bt }B{BR R{ ? Z}ZjBR }s s Ys{ `ZR ${$s _ RBts` I Zt {? B8${ P st{? R JZ Is s I d E1 jj s s js }st sjjs t js } j? {Zjs YB8? Bt$8s I d EM et j hj8 s As jjs R t%$sIs {B8B s t R s js {$ZIsI I 7B B ZA${sIs
t j }jst s Nk Y$Bt IBtI AZR{s sj I Rs}s {$IB {$ t ? h{B *Z stIT*Z stI j {Zsj }BR j I R Z{ B
skB }BR$ ? Bt${B
w D
]Bt Zts R ? ${s k }Z R s t R{ ts R$8$js s js I 3jsRY
pB IBt jB I 8 tBR sJZ? R js % BR$8$j$ ZI I j js B ts sIB VR ? JZ tBR } 8$ $ ? st JZ tB Ys s8BR t$t Zts { ? ${s I RI j }Zt B I %$R B P? R${B RBA jsR s{{$Bt R k R$ Zs{$Bt R t JZ R % t%Z j B st R$t Zjs } RBts`
Vt R I htsj$9s R A % }sRB I jBR Y? B R I js h{{$? Bt 8 tBR
IB sIBR
I RI j }Zt B I
%$R s I RZR }BI R sZtJZ tB 8 tBR RZ} %sj$ t R } {$RB R {B Is {Bt {$ s tBR sj $s s B BR } RBts` R t R {sRB I tZ R B }s ? R JZ s8A$? t Yst Y {YB RBK ts s %s $sR t s{$Bt R I `? B% t R t Zts ? }B{s js }BR Z s tB I 8sR$sIB } I$R}Z R s s jsR {Bt{ R$Bt R k %sR$Bt R I R $}B
-
et sK tsAj R Y? B R {B8B
*$ B zsjB
>d x;H B
iB{, zst Zs I
>d xMH {ZksR
Ys9sK tsR }B{B $ t t JZ t%$I$s s jsR JZ sj$9st RZR YB8? BjB BR I j {? B8${ tB s8 ${stB
g_Z8 g sR g]s s{ s{
V }s I RZR As s $jZ $BR
s 8st {B8B B BR RZ} Y? B R {Z s 8 tZIB s RZR }ZK tBR
}s s I$ $8$ RZR I$P t{$sR {Bt BIB $}B I 8sj%sIBR eR R Zt 8B $%B 8? sR JZ RZh{$ t {B8B }s s JZ tBR I t s8BR s stsj$9s j P { B I jBR }ZK t s9BR qBIB {YBJZ {BtR$R t Zts stRP t{$s I js {st $IsI I 8B%$8$ t B t jBR BA ` BR JZ $t s{{$Btst V I$P T
t{$s I jBR {YBJZ R t ABjsR ? $IsR {B8B jsR I j `Z B I j A$jjs js 8sRs $t%BjZ{ sIs t Zts I$R}Z s wRZ} Y? B JZ Bj} s k 8sj%sIB JZ {$A D I } tI I js }s I j {Z }B JZ
Zt 8 {$IB YB8 ts`
=ts I jsR R{sRsR P t{$sR s Rs }j? ksI I Y? B R {sR BR R js -}BR${$? Bt ]$ t{$s h{{$? Bt s YsA ? s JZ tI$ Ns {tBjB ? s t jBR {? B8${R I jBR sK tBR {$t{Z t s >d MH _ RBts` R s jBR JZ Zt I? -
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
dnx
R Z $j$9s k I {? B8B R 8}j s ? R s VI 8? sR I A t R t {Z t s JZ {ZstIB R Bj} s Zt BA` B Zts }s I js {st $IsI I 8B%$8$ t B R stR8$ sj RZ jB _s s R$8}j$h{s j R ZI$B R s{BR Z8A s s $t BIZ{$ j {Bt{ } B I } 8$ {BtR$I s j R$R 8s Bj} sIB T Bj} sIB s$RjsIB I PZ 9sR - $B R k Ys{ }BR$Aj js s}j${s{$? Bt I j } $t{$}$B I {BtR %s{$? Bt I js {st $IsI I 8B%$8$ t B 7$ t 8BR } R t JZ js {st $IsI I 8B%$8$ t B R j } BIZ{ B I js 8sRs }B js % jB{$IsI Zts stRP t{$s 8? s-$8s I R s 8s t$ ZI P? R${s }sRs }B sZ8 t s js 8sRs P { $%s js % jB{$IsI B s8AsR s js % 9 VR? R }Z I Bj} s $t%BjZ{ stIB js 8sRs I BIB j {Z }B {B8B t j AB- B B A$ t Ys{ $t % t$ Zts }s js 8stB B j }$ t Zt 8B%$8$ t B ? s}$IB {B8B t j ,? s s et R Z ?j $8B {sRB j }ZK tB R 8Z % s} B-$8sIs8 t t j? t s { s k j $8}s{ B R } BIZ{ {ZstIB RZ % jB{$IsI R 8? s-$8s eR B RZ{ I {ZstIB j A s9B R ? s - tI$IB t Zt (0 I RZ jBt $ ZI R$ tIB js % jB{$IsI t Bt{ R I ZtBR x, x 8bR
8sRs P { $%s I j BA` B JZ Bj} s B } {Z B eR B
et Zt {YBJZ $t j? sR ${B IBtI jBR BA` BR R 8Z % t {Bt`Zt s8 t I R}Z? R I j $8}s{ B js {st $IsI I 8B%$8$ t B R 8st $ t {BtR st } B js t ? s {$t? ${s I j R$R 8s tB R {BtR %sU Zts P s{{$? Bt I js 8$R8s R $t%$ t js I PB 8s{$? Bt I jBR {Z }BR JZ t st t {Bt s{ B k t {sjB et j {sRB I Zt BA` B I Zts {$ s 8sRs JZ R 8Z % s Zts {$ s % jB{$IsI k JZ $8}s{ s {Bt B B JZ R t{Z t s t }BRB RZj s R t{$jjB t{Bt s Zts js{$? Bt t js t ? s {$t? ${s } I$Is t js {Bj$R$? Bt k js t ? s {$t? ${s $t${$sj I j BA` B ej {B{$ t I t ? sR {$t? ${sR R ? s js{$BtsIB I PB 8s $t% Rs8 t } B}B {$Btsj {Bt j {B{$ t I 8sRsR eR RZj sIB } 8$ I 8BR s JZ jBR Bj} R } B}$tsIBR }B Zt ,s s {s RBt I RI Zt }Zt B I %$R s t ? ${B 8? sR P { $%BR JZ jBR }ZK t s9BR JZ $t {s8A$st t R? jBR }? Z $j R I Zt {B8As I AB- B ej AB- sIB Z $j$9s BIB RZ {Z }B t j Bj} U jsR 8sRsR I j Bj} sIB k I j Bj} sIB RBt R 8 `st R j ,s s {s }B j {Bt s $B 8}j s tB 8sj8 t Zt RBjB 8$ 8A B w8stB }$ D JZ Bj} s RBA j {Z }B I j {Bt $t{st Zt BA` B I 8sRs 8Z{YB 8skB Ns stRP t{$s I t ? s k }B st B j IsK tB {sZRsIB R 8skB t R R ZtIB {sRB et j ,? s s $t Rs IZ{$ sj sI% Rs $B s AsR }B ` 8}jB I P s{ Z s j sj ? Zt YZ RB eR B JZ$ Bj} R ? s}$IBR k Zts st $t {s8A$B t ? ${B et j AB- B R $t t s IB8$ts sj {Bt $t{st j t s8 t 8 I$st Zts RZ{ R$? Bt I }ZK t s9BR Ns IZ s{$? Bt I j $8}s{ B R s8A$? t 8skB s {sZRs I j ZRB I Zst R ej $t {s8A$B I t ? s t {sIs Bj} R 8 tB
z s8BR Zt }s I ` 8}jBR $jZR s $%BR I jB JZ s{sAs8BR I I {$ =t RZ} Y? B {B8B 3jsRY s{BR Z8A s s I RYs{ R I RZR t 8$ BR s }ZK t s9B j$8}$B _BI 8BR } tRs JZ RZR }ZK t s9BR RBt st ? s}$IBR {B8B jB R RZ % jB{$IsI t {B8}s s{$? Bt {Bt js I Zt YB8A tB 8sj R I {$ Zt Ps{ B 1x 7Z}Bt$ tIB Zt $ 8}B I $8}s{ B I Zts { t ? R$8s I R ZtIB w JZ$%sj t }B ` 8}jB sj $ 8}B t JZ Zt Asj? Bt I P? Z ABj R ? s t {Bt s{ B {Bt js AB s I j `Z sIB IZ st t s9BR R ? s I E31x( W ZtsR EM % { R RZ} $B s js j }Zt s}$? D js PZ 9s 8 I$s I RZR }ZK PZ 9s 8 I$s ` {$Is RBA Zts } jB s I P? Z ABj IZ st Zt }Zt s}$? gVR? JZ 8? sR %sj tB }Bt R sj sj{st{ I RZR }ZK tBR VZtJZ 5{? B8B jB s jB R$ sI 8? sR R I Zts s $j$IsI }sR8BRs2 sj jB $ t t jBR %$jjstBR JZ BRst I Rshs jB sj {B8B js R $ j %$R$%s JZ } B s Bt$9s R Zt st $Y? B {B8B sI s- et Zts I jsR R {Z t{$sR { t sj R I js } j? {Zjs sI s-U 8? sR sjj? s I js ]? Z}Zjs I j q Z tB > sI s- kBtI qYZtI IB8 d MxH R tP t s t Zts {s8} ? Bt I j A$ t R t{s s I 8BR s _ZK t s9BR st Bj? B ${BR RBt s8A$? t jBR JZ } B}$ts
© Los autores, 2001; © Edicions UPC, 2001.
dnE
* $t Bt s e$tR $t
jZ{Ys s 8Z s Zt $8}Bt t k - sK tB jZ{YsIB U
j
s R B Bj} sIB
_BI 8BR R $8s
js PZ 9s 8 I$s ` {$Is RBA RZ sI% Rs $B t j 8B8 t B t JZ jB Bj} s {Bt Zt }ZK t s9B ? s}$IB k R {B w{Bt R{sRs PB Zts }B jB JZ R % }Z R B JZ j tB 8 {Bt tI$ t s} tsR R $t8Z sD 7Z}BtI 8BR }s s jjB JZ sR j Bj} j }ZK tB k js {sA 9s I j {Bt s $B R Ns PZ 9s 8 I$s ` {$Is R %sj? Zs I$%$I$ tIB js %s $s{$? Bt I js
8Z % t I PB 8s {Bt`Zt s
{st $IsI I 8B%$8$ t B I j A s9B t j $ 8}B I {Bj$R$? Bt qB8stIB ZtBR %sjB R s9BtsAj R }s s jsR 8s t$ ZI R $t%BjZ{ sIsR w}B ` 8}jB 8sRs I j A s9B , 8sRs I js {sA 9s I j {Bt $t{st E , % jB{$IsI I j }ZK tB x, x 8bR $ 8}B I IZ s{$? Bt I j Bj} (, (d RD js PZ 9s 8 I$s ` {$Is RZj s R I d3 M( W JZ JZ$%sj s ZtsR 1 % { R j } RB I Zts } RBts
! B 8s8}B B I {Z$IsIB R j
]s}$ ? st V8? ${s
7? 8ABjB 8Aj 8? s ${B I jBR %sjB R
}s $? B ${BR I j }Z AjB tB s8 ${stB R RZ} Y? B PZ { sIB }B FB 7$8BtR k j } Bj? h{B Fs{, $ Ak t d ;d * RI t Bt{ R k sj $ Zsj JZ B BR I RZR {Bj sR Ys } B s Bt$9sIB
R $sj R >d ;;H j hj8 R >d (H k YsR s Zts } j? {Zjs >d M H Ns 8$R$? Bt JZ $ t t{B8 tIsIs Ys $IB %s $stIB s 8 I$Is JZ jB Ys{? st jBR t 8$ BR I WB s8? ${s 7$ } $8 B PZ Bt jBR
ts9$R Zts % 9 htsj$9sIs js yy pZ s ZtI$sj R ? s j {B8Zt$R8B sZtJZ Ys s{sAsIB AsT sjjstIB RBjB B t {B8}sK t? s w t {BjsAB s{$? Bt {Bt j Z}B I RZ} Y? B R I
NBR z t sIB R
D
} ? s{ ${s8 t {Bt s BIB j 8ZtIB 3$ j 4 `B I j R t $ I j {$ZIsIstB 8 I$B tB s8 ${stB Ys }sRsIB s8A$? t }B Zts s}s j$A sj eR RZ} PB 9ZIB R t sj$IsI 7 % iB R Zt
R8$ $sIB YZ8stB JZ tB IZIs t RB8 R s Zt -} $8 t B 8$j$ s }s s {BtR Z$ R R s ZR 7Z RZ} }BI $tIZ{$IB R s % 9 }B } B{ I$8$ t BR } RZt s8 t {$ t ? h{BR R$I t RZ RZ} PZ 9s z s8BRU j 8? ZR{ZjB I Zt st$8sj R ? s {B8}Z R B }B 8$jjs R I htsR
hA sR sjs sIsR NsR R K tsj R j? { ${sR t%$sIsR }B j R$R 8s t %$BRB } BIZ{ t {Bt s{{$Bt R I R sR hA sR t $tR st R I$P t R k t I$R $t BR jZ s R I j 8? ZR{ZjB ? R R {Bt s k ` { }B {BtR$ Z$ t Zts PZ 9s ]B8B RZj sIB
Ns PZ 9s B tR$? Bt 8? s-$8s I Zt
8? ZR{ZjB R } B}B {$Btsj sj s ? s I RZ R {{$? Bt stR% Rsj t j }Zt B 8? sR st{YB eR s PZ 9s I } tI s8A$? t I js jBt $ ZI I j 8? ZR{ZjB ej %sjB 8? s-$8B R {BtR$ Z {ZstIB j 8? ZR{ZjB R t{Z t s t Zts }BR${$? Bt { {sts s js I I R{stRB B R$t } Z As k %sj t n( k ;( Wb {8 eR %sjB I$R8$tZk {Bt s}$I 9 R$ j 8? ZR{ZjB R sjs s B R
s{B s
V $ ZsjIsI I s8sK tB NBR j %st sIB R I
}s s sZ8 t s js PZ 9s R JZ$ Zt sZ8 t B I js R {{$? Bt 8ZR{Zjs
} RB }B ` 8}jB $t t st sZ8 t s t jB }BR$Aj RZ RZ} h{$ 8ZR{Zjs }s s 8 `B s RZR 8s {sR qsj % 9 sj ZtsR I jsR Ys9sK tsR I tZ R BR RZ} Y? B R JZ I t `ZR $h{sIsR {Bt R sR sR {BtR$I s{$Bt R w}B RZ}Z R B tsIs I j %st s {s8$Bt R t$ }s s t R {B8B % 8BR 8? sR sI jst D } B 8Z{YB tBR 8 8BR JZ RZR RZ} 8ZR{ZjsIBR B RBR k 8$ 8A BR tB R st 8? JZ {Bt{ R$Bt R s js R ? ${s {B }B sj
et {Bt{ B js PZ 9s JZ sIJZ$ j ]s}$ ? st V8? ${s } BIZ{ B I js {B8A$ts{$? Bt I j RZ B R} {$sj JZ R j $tk { s {Bt Zts AZ ts IBR$R I j { ${$IsI RZj s R {$ t % { R RZ} $B s js JZ }BR ? s {B8B $tI$%$IZB tB 8sj 7$ {B8B s{sAs8BR I -}Bt {BtR$I s8BR JZ js PZ 9s 8ZR{Zjs R } B}B {$Btsj s js R {{$? Bt 8ZR{Zjs jBR 8? ZR{ZjBR I j RZ} Y? B I A ? st t Zts RZ} h{$ {$ t % { R RZ} $B s js I j R8$ $sIB 7 % iB R $Ist ZR I R j } ? 8 B I RZ 8? ZR{ZjB A? { }R k I$%$Ist RZ %sjB t $ U Ysjjs ? st j I$? s8 B I j 8? ZR{ZjB t RZ }s
_s s {B8} BAs jB $t t }B ` 8}jB { s j }ZK tB B {B Zt BA` B {Bt js 8stB 8st T t$ tIB js 8ZK t {s $t{j$tsIs
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
dn
3$ n x wV $AsD s 8st k iBA$t jZ{YstIB }B j A$ t s AsR I 8s8}B BR ej R $jB k R ? ${s I js R $ j %$R$%s I d EE $8$ s st A$ t sj {? B8${ JZ $t{jZRB jsR BtB8s B} ksR I Bj} R k }ZK t s9BR s}s { t R{ $ sR t jsR R{ tsR wVAs`BD =t ]s}$ ? st V8? ${s 8B s8 t }s {$IB sj I j {? B8${ B $ $tsj
© Los autores, 2001; © Edicions UPC, 2001.
dnM
* $t Bt s e$tR $t
8? sR st{Ys 8Zj $}j$JZ t jZ B j RZj sIB BA t$IB }B d( q tI ? st sR? Zts R $8s{$? Bt I js 8ZR{Zjs Z s JZ h j R s jsR $tI${s{$Bt R I RZR Z$Bt$R sR I A ? s t RZ Y? B Ps%B $ B 7$ j RZj sIB tB R }s { t tsIs s jB JZ R} sAst tB R } B{Z} t WB R Yst JZ$%B{sIB eR JZ {B8B ks YsA ? st }BI$IB {B8} BAs jBR Z$Bt$R sR tB s{BR Z8A st s R {BtR {Z t R ! BR sR} { BR js{$BtsIBR {Bt R } RBts` RBt I$ tBR s8A$? t I 8 t{$? Bt 7$ t j {sRB I 3jsRY js $tIZ8 t s $s I RZ} Y? B s {sR$ Zts t { R$IsI k t j I s 8st j I$R{ B {BjB t B I RZ $8}Bt t s` j R$ % sj RZ} Y? B }s s 8B% R I PB 8s RZA } ${$s }B js tB{Y w{Bt stIB {Bt jsR 8sj $jZ8$tsIsR {sjj R I pB Ys8 ]$ k BIB Ysk JZ I {$ jBD ZtB R } Zt s JZ? Ys{ j ]s}$ ? st V8? ${s % R $IB {Bt jBR jjs8s $%BR {BjB R I js AstI s tB s8 ${sts 5_ B{js8s s jBR {Zs B %$ t BR RZ }s $B $R8B s Zj st9s2 ej {BjB $IB I RZ $tIZ8 t s $s sj % 9 I? j } B t Zts h R s I {s ts%sj } B Ys{ I ? j Zts Ajst{B P? s{$j }s s RZR t 8$ BR RBA BIB {ZstIB {B8B RZ{ I t Zts R{ ts I j hj8 ]s}$ ? st V8? ${s >]s} s$t V8 ${s d (H $t t s s{ {s R s Zts AsR 8$j$ s ts9$ R$ ZsIs t 8 I$B I js R j%s Zt { ? ${B Ys I ht$IB s R RZ} Y? B {B8B Zts Vj 8s t I RZ R sPsjs $s $tIZ8 t s $s wsj ? AstI s {Bt }s sRD jB 8? sR tB sAj I R RZ} YB8A R RZ R{ZIB 7$t ? j tB R 8? sR JZ Zt R$8}j PB 9ZIB 8? sR eR s $jZ $B }BR } B}$ IsI R $tRBR} {YsIsR V }s I RZ s{ Zs{$? Bt {B8B R$R 8s I I P tRs $8} t sAj w{s}s9 I R$R $ s skBR AsjsR { D js YsA$j$IsI I RZ } B}$ s $B } 8$ JZ }Z Is Z $j$9s R {B8B s 8s I {Bt ss sJZ U t B s R{ ts I js } j? {Zjs RBA j } RBts` tB RBjs8 t {BtR$ Z }s s Zts Asjs {Bt I${YB R{ZIB R$tB JZ ? R s Rsj s AB sIs t js I$ {{$? Bt {B { s }s s Y $ s B B sI% Rs $B Ys{$ tIB sjs I ZtBR AZ tBR {BtB{$8$ t BR I P? R${s A? sR${s V 8 tZIB R ZRsIB {B8B R$8}j s 8s s B`sI$9s Ns {B8}j `s sk { B $s I jBR AZ8 st R s 8sR Z $j$9sIsR }B jBR sAB ? t R sZR sj$stBR k {BtB{$IsR ks t js st $ [ Z IsI R AsRs t jsR PZ 9sR I P ${{$? Bt JZ s}s { t {ZstIB Zt {Z }B R I R}js9s t j R tB I Zt 4Z$IB {B8B j s Zs B j s$ U RBt jsR I tB8$tsIsR PZ 9sR I s sR eR sR {Zj Z sR R t ts Bt t j s I {B8A$ts $tR $t $%s8 t j $8}ZjRB I j jst9s8$ t B js B s{$? Bt I j AZ8 st k js R$R t{$s I j s$ k {BtR Z$ t j {sRB I s j $ B JZ j s 8s B tsR RB } tI t 8 t sj }Zt B I }s $Is Vj $ Zsj JZ jBR AZ8 st R j R{ZIB I j ]s}$ ? st V8? ${s I A ? s %Bj% sj }Zt B I jst9s8$ t B R? BjB t {sRB I YsA sIB j $ B _ B {B8B Zt RZ} Y? B tZt{s Psjjs I A RZj s 8Bj R B j t JZ $ s {B R$ 8} j R{ZIB VR? JZ jBR Z$Bt$R sR } tRs Bt JZ R ? s 8Z{YB 8? sR {? B8BIB JZ j R{ZIB %Bj%$ R R$ 8} s js 8stB I RZ jst9sIB g$tI } tI$ t 8 t I JZ Y${$ R Ajst{B B tB et js } j? {Zjs g j R{ZIB B ts sj RZ} Y? B I R}Z? R I I R Z$ Zts B I %$ $jst{$s ]B8B tB R BAR %s t$t ? Zt {YB B I sR JZ I js js } R t{$s I Zt 8B B j${ R { D R? BjB {sA s $AZ$ s js 8}s ? s JZ j s $jZ $B R$ t }B RZ t$ }s R 8? B%$j R wY? } B}$ s $B js -}j${s{$? Bt I R - sK tB {B8}B s8$ t B et jBR stI R I j }ZK t s9B j$8}$B R Ysjjs Zt s ? }${B R js sRs =t } RBts` { sIB }B jBR } Bj? h{BR 7 st N k Fs{, $ Ak t d E1 JZ I s8AZjs t js j? t s I$%$RB $s JZ R }s s js Y B${$IsI k js %$jjst? s $ t sR JZ t j {? B8${ Ys R$IB k R Zt } RBts` YsR s RZj ? Bt JZ {Z t s {Bt Zt st t? Z8 B I R Z$IB R RZR $t{Z R$Bt R t js j %$R$? Bt k t j {$t wNs sRs >qY yt{ I$Aj <Zj, d HD tB Yst R$IB I 8sR$sIB 8 $ B $sR 7 ? s ${B k s B 8 t sIB IBtI jBR Ysks }B RZ IBAj } RBtsj$IsI %$ t s R Zts 8 9{Bjst9s I j 8BtR ZB I 3 st, tR $t st t % I I j JZ Ys Y IsIB RZ {sA 9s }jsts k Zts }$ j $R? s{ s wJZ jBR Z$Bt$R sR B{s ?
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
dn
AB jjs {Bt }BR $B $IsID k I j *B{ B F {,kjj k $R <kI Z{ stt R Zt {$ t ? h{B JZ sAs`s {Bt sI$s{$Bt R s88s JZ R % sP { sIB }B Zts -}jBR$? Bt sI$s{ $%s s{{$I t sj w8? BIB ZRZsj }s s {Bt% $ R t $tI$%$IZB PZ s I jB {B8? ZtD V }s $ I R 8B8 t B {sIs % 9 JZ R -{$ s R {Bt%$ t Zt R 8BtR ZBRB I R 8 BR I sj Z s IB sIB I Zts PZ 9s I R{B8Ztsj WB t { R$ s 8? sR JZ RZR }ZK tBR }s s Is $ tIs RZ j s s RZ s R$%$IsI {Bt t$Is et j {? B8${ }Z I %? R j jZ{YstIB {Bt s BIBR jBR RZ} Y? B R k ts8 t } R Z$IB }B j `? {$ B k js }Bj${? s * % 9 t {ZstIB RZR t j PBtIB AZ tBR R t $8$ t BR j jj %st s sj$9s s{{$Bt R } B}$sR I Zt RZ} Y? B ]ZstIB j tPsIB k js -{$ s{$? Bt R j }sRst {Z} s RZ R sIB B $ $tsj k %Z j% s R j }s{? h{B Z{ stt V I$P t{$s I jBR `ZR ${$ BR JZ Y 8BR %$R B R s { $s Z s $ t 8Z{YBR } BAj 8sR }s s jj %s RBA RZ 8ZR{ZjBRs }$ j sj B 8? sR JZ Ys s}BR ]sIs % 9 JZ -} $8 t s js stRPB 8s{$? Bt B8} BIs RZ B}s sZtJZ {BtR %s RB R? ZtBR I RY$js{YsIBR k {s sIBR }st sjBt R JZ {Z $BRs8 t sZ8 t st I s8sK tB sj $ Zsj JZ RZ {Z }B gWB sts }s s {s8$RsR * I? BtI Rs{s js 8sRs sI${$Btsj }s s jj ts RZ {B }s{Y? Bt k I? BtI js Zs Is Zts % 9 B ts sj R sIB tB 8sj RBt {Z R $Bt R JZ jBR Z$Bt$R sR tB tBR Yst I R% jsIB qs8}B{B RZ $t{ ? Aj PZ 9s JZ j } 8$ st B s}jsR s Zt {B{Y {B8B s st{s I {Zs`B Zt s ? ABj $ t -}j${s{$? Bt VZtJZ A$ t R {$ B JZ st B }B RZ R s Z s {B8B }B js 8ZR{Zjs Z s JZ }BR R {BY t sR$ ts j Zts PZ 9s A Z s RZ} $B s js I Zt 8ZR{ZjsIB YZ8stB tB jB R 8 tBR JZ j sZ8 t B I 8sRs I R {B8B %$8BR t j I A$ s t {BtR {Z t{$sR {Bt s $sR } B}$sR I RZ $ st $R8B w {Z? {s}? ZjB d JZ js PZ 9s js $%s I$R8$tZk {Bt j s8sK tBD
7}$I 8st j RB } tI t YB8A s sK ts _ _s , Zt `B% t R ZI$st k PB ? B sPB R }${sIB }B Zts s sK ts sI$s{ $%s _B{B s }B{B tB s {B8B %s sIJZ$ $ tIB jsR Ps{Zj sI R I Zt s ? s{t$IB sZtJZ 8st $ t RZ s}s $ t{$s YZ8sts Ns %$R$? Bt k j B? IB R j s ZI$9st R B ts % jB9 t jsR s{{$Bt R $tR $t $%sR I Rs Bjjs js {s}s{$IsI I RZA$ R }B jsR }s I R k jst9s Zt `$IB R$8$js s js R Is {Bt j JZ }Z I {Bj s R B s s}s s RZR } RsR gVY k {B8B R YsA$ Zsj sIJZ$ Zts %sj t ? s s Zj st9s V }s $ I R 8B8 t B B{Zj s RZ IBAj $I t $IsI {Bt Zt %$R BRB % R $IB B`B {Y$jj? Bt {Bt j R? 8ABjB I Zts s sK ts I$AZ`sIB t j } {YB JZ j {ZA I RI js {sA 9s YsR s jBR }$ R ej } RBts` $I sIB }B Fs{, $ Ak k I Rs BjjsIB }B 7 % *$ ,B s}s { t d E1 {B8B qY V8s9$t 7}$I 8st zs $sR R $ R I I$AZ`BR st$8sIBR k R } j? {ZjsR w7}$I 8st >7}$I T st d H 7}$I 8st 1 >7}$I T st 7 $, R s{, d MH 7}$I 8st j I RsP? B I j I s ? Bt >7}$I T st qY * s Bt:R ]Ysjj t d M(HD s%sjst RZ sk { B $s eR j } B B $}B I Y? B {Bt } BAj 8sR VZtJZ $tsR JZ$Aj sj I Rsj$ t B Ys{ j A$ t s } Rs I RZR 8? Zj $}j R I R s{$sR s skD V jsR I$h{Zj sI R {Bt? B8${sR }s s jj s s htsj I 8 R w $ t s RZ {s B s Zts ? R j sK tsI t jBR {Bt4${ BR I$s $BR {Bt j $ sR{$Aj I$ { B I j } $? BI${B }s s j JZ sAs`s Vj B sP s{sAs R$ 8} s{ZRsIB I {ZsjJZ$ I j$ B JZ ks {B8B 7}$I 8st 8$ts ? s }B RBj% et RZR RZ} }BI R JZ$9? sR j 8? sR jjs8s $%B R s js YsA$j$IsI sIJZ$ $Is I }sR s R {B8B R$ sj {BRs }B jsR }s I R k jBR {YBR I jBR I$h{$BR ]sA $8s $ts JZ R j s` I RZ} Y? B JZ$ t j {Bth R }BI Vtsj${ 8BR s {Bt $tZs{$? Bt sj ZtsR Y$}? B R$R }jsZR$Aj R JZ }BI ? st -}j${s R {B8}B s8$ t B % IsIB sj YB8A U
© Los autores, 2001; © Edicions UPC, 2001.
d;(
* $t Bt s e$tR $t
]ZsI B n d 7ZA$ R }B jsR }s I R _s s RZA$ R }B jsR }s I R B {s8$ts }B j {YB Ysk JZ t Zt s8sK tB } JZ K tB NBR st$8sj R JZ R }sR st }B jsR }s I R $ t t I$8 tR$Bt R } ? B-$8sR sj s8sK tB ? { ? ${B } R t sIB t j ? sh{B eR R j RZj sIB I j JZ$j$A $B t j } RB wPZ 9s I js s% IsID JZ 8}Z`s Ys{$s j RZ jB k js PZ 9s I {BY R$? Bt I B $ t j? { ${B JZ $ tI s 8st t sIY $IB j B st$R8B s js }s I NBR R{s sAs`BR }B ` 8}jB }BR t ZtsR }s sR sj8BYsI$jjsIsR {ZksR } JZ K tsR } B ZA st{$sR j R } 8$ t sP s R s jsR I$8$tZ sR $ Zjs $IsI R I RZ} h{$ R s}s t 8 t j$RsR NsR Rsjs8stJZ RsR B BR R{Z $I$9BR }sIB R t jBR j? 8$ R I j s8sK tB { ? ${B $ t t Zts R} {$ I sj8BYsI$jjsR B js8$t$jjsR R$8$js R t jBR I IBR I RZR }s sR JZ PZt{$Btst I PB 8s }s {$Is
NBR $tR { BR k B BR } JZ K tBR st$8sj R JZ }ZjZjst }B }s I R k {YBR R t{Z t st }B I As`B I Zt s8sK tB { ? ${B }Zt B I $t R {{$? Bt t js j? t s JZ } R t s j } RB {B }B sj } B}B {$Btsj sj {ZAB I j s8sK tB I j B st$R8B k js j? t s JZ 8Z R s js PZ 9s I {BY R$? Bt I$ { s8 t } B}B {$Btsj sj s8sK tB wsIs} sIB I 3 G t d EMD 6 NB } $8 B JZ s ZtB R j B{Z R JZ js }s I j s` I 7}$I 8st JZ {ZA jsR }sj8sR
I RZR 8stBR k jsR }jst sR I RZR }$ R }BR sj ? Zt $}B I RZR st{$s sIY R$%s JZ } 8$ 8st t sj RZ` B {Bj sIB I j {YB ]Bt Zt AZ t } s8 t B }BI ? s jB s R 7$t 8As B js RBj Z s {Bt JZ 7}$I 8st %BjZ{$Bts }B j {YB {Bt sI${ R 8 {st$R8B I RBR ? t _s s I R}js9s R I A ? s I R t st{Ys k t st{Ys sj ts $%s8 t 8stBR k }$ R jB {Zsj j R s ? s 8B%$j$IsI k R ? s s js js s Zts s s } RsIs
© Los autores, 2001; © Edicions UPC, 2001.
n *Â&#x201A; 7Z}Â&#x201A;Â&#x201E;8st sj YB8AÂ&#x201E;Â&#x201A; $t%$R$AjÂ&#x201A;U ? IBjBR {Bt }$Â&#x201A;R IÂ&#x201A; AsÂ&#x201E;Â&#x201E;B
d;d
3$ n E ! Â&#x201E;B RZ}Â&#x201A;Â&#x201E;Y? Â&#x201A;Â&#x201E;BÂ&#x201A; IÂ&#x201A; }$`s8s s`ZR sIBU 7}$IÂ&#x201A;Â&#x201E;8st Â&#x201A;j $t{Â&#x201E;Â&#x201A;? AjÂ&#x201A; YB8AÂ&#x201E;Â&#x201A; sÂ&#x201E;sK ts ]sÂ&#x201E; Â&#x201A;j }ZAj${$ sÂ&#x201E;$B IÂ&#x201A; js }Â&#x201A;j? {Zjs 7}$IÂ&#x201A;Â&#x201E;8st >7}$IÂ&#x201A;Â&#x201E;T st d H
Š Los autores, 2001; Š Edicions UPC, 2001.
d;1
* $t Bt s e$tR $t
6 qsj % 9 I$R}Bt I } JZ K tBR } B }B t R j { B$8st R {Zks PZ 9s I s s{{$? Bt 8s t? ${s }Z I %s $s R jj stIB $t{jZRB s stZjs R s %BjZt sI *$R}BR$ $%BR I R sR {s s{ ? R ${sR R Z $j$9st }B ` 8}jB }s s $9s stI R } RBR t jBR I R Zs{ R I sZ B8? B%$j R _s s 8B% R {Bt s $j$IsI }B j {YB t }BR${$? Bt $t% $Is AsR s JZ {Bt { k I R{Bt { j j { B$8? st _ B gsk j R$R 8s R? BjB R %$ ? s t {YBR k }s I R I 8 sj {B8B j Y$ B IBtI js PZ 9s 8s t? ${s ` { RZ s{{$? Bt 6 ! s }BR$A$j$IsI R JZ js }s I j % R $IB I 7}$I 8st t {Bt s{ B {Bt js }s I R ? {BtR $ Z$Is }B R RZ` sIB Zt$% Rsj I st - tI$IB ZRB JZ R j % j{ B w{Bt s{{$? Bt s PB 8sIB }B Y$j sR I I jsR }sjsA sR P st{ RsR % jBZ R {$B} jB k { B{Y st{YBD eR ? I$8$tZ BR st{YBR wI t ( ; k 1 x 88 I s8sK tBD k B`sj R {Zks Zt$? Bt } 8$ {BtR Z$ R$R t{$sR PB 8$IsAj R =t } Is9B {ZsI sIB I 1 {8 I jsIB }Z I {Bt t Zt }s I 8$j R I R BR st{YBR k B`sj R ]BjB{sIB t Zts }s I }Z I s Zst s } P { s8 t j } RB I Zts } RBts I M( , Ns R$R t{$s JZ B}Bt sj I RsA B{YsIB st Zts PZ 9s I s{{$? Bt } } tI${Zjs s js AsR I jBR st{YBR BtIs jBR d x , {8 7$t 8As B {ZstIB R $ s I jjBR BAj${Zs8 t st{YBR k B`sj R R R }s st {Bt Zts PZ 9s RB } tI t 8 t 8 tB U js PZ 9s s{ ? Zs RBA Zts Y$j s k tB RBA j {Bt`Zt B k RZj s RZh{$ t }s s I R t st{Ys } B R$%s8 t BIs js }$ 9s et j {sRB {Bt{ B {B8 t sIB }B ` 8}jB AsR s Zts PZ 9s t ( n k d ; , NsR {s s{ ? R ${sR I j % j{ B st R$R t{$s k Ps{$j$IsI I I R} sIB jB {Bt%$ t t Zt {stI$Is B $I? Bt B }s s j s R tsj I 7}$I 8st 7$t 8As B {B8B t js Y$}? B R$R } { I t j R$R 8s R? BjB R ? s P { $%B R$ jBR {YBR k }s I R R Z%$ R t {ZA$ BR }B j 8$R8B `$IB , , , b , ,
Ns Y$}? B R$R 8? sR R$8}j I R{s sIsR jsR st $B R {BtR$R t {BtR$I s JZ 7}$I 8st RZA }B jsR }s I R s{$sR s JZ R Zt R{sjsIB PZ s I R $ WB t { R$ s t$ {Z IsR t$ Zts st IBR$R I Rst P ? sD }s s t{s s8s R }B jsR }s I R I Zt sR{s{$ jBR tsIs w RB R? Vj B JZ ks Ys{? s j {? B8${B <s BjI NjBkI t j hj8 ej YB8A 8BR{s >d 1nH eR B {js B R ? s R$ Z I `stIB R$t -}j${s{$? Bt {? B8B R 8st $ t RZR} tI$IB t j {YB et Zts R{ ts I js } j? {Zjs 7}$I 8st j RZ} Y? B }s }B jsR }s I R I Zt I$h{$B }s s Rsj%s s Zt RZ${$Is JZ R ? s s }Zt B I s B`s R }B Zts % t sts ]BtR Z$IB RZ } B}? BR$ B {s s {Bt sJZ? j k Ys{$? tIBjB 8? sR I$P? {$j BIs%? s I RstIs jB stIsIB k %Z j% s js s9B s I j I$h{$B I RI IBtI YsA? s }s $IB =tB R } Zt s R$ tB YZA$ R R$IB 8? sR R t{$jjB Zts % 9 sj{st9sIs js % t sts YsA {B $IB sj P ZR sIB RZ${$Is k YsA As`sIB B RZA$IB }B js R{sj s B j sR{ tRB {B8B BIB j 8ZtIB WB { 8BR JZ sj }BA YB8A j JZ I t stsR I %Bj% s $t t s jBU gjs -} $ t{$s %$%$Is RZA$ tIB }B Zts }s I % ${sj s R}sjIsR I 7}$I 8st R I sJZ jjsR JZ tB R Bj%$Ist qs8A$? t t js % R$? Bt 8BI ts I j {j? sR${B Ns BR{s >qY 3jk d MEH }Z I % R sj t tI B 8 I$B YZ8stB 8 I$B 8BR{s t PsR I stRPB 8s{$? Bt }sR ? stIBR I RtZIB }B j {YB I js YsA$ s{$? Bt ej YsA sIJZ$ $IB }s I js R Z{ Z s 8Bj {Zjs I Zts 8BR{s tB j Is t$t ? Zt I {YB s jjB }B 8Z{YB JZ R 8} K t t jBR Z$Bt$R sR ]s8$ts }B j {YB I } tI I j s8sK tB et j {sRB I 7}$I 8st }BI? s AZR{s R t j % R $IB js {js% I sj Ys9sK ts } B tB R R j {sRB 7 s s I Zts R{ ts $t% BR? 8$j 6
7$ RB } tI t R js YsA$j$IsI I Zt RZ} Y? B {B8B 7}$I 8st }s s RZA$ R }B jsR }s I R tB jB R 8 tBR j s $jZ $B JZ Z $j$9s } BPZRs8 t st B }s s I R}js9s R I I$h{$B t I$h{$B
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
d;n
3$ n 5<s } tRsIB ZR I R K tB 7}$I 8st t IZ{$ RZ s8sK tB2 {B8B }s s {s} Z s 8sj%sIBR B jB JZ R {$ 7 s s I RZR {BtB{$IsR js sK tsR _B jB JZ }s { RBt I PsA ${s{$? Bt } B}$s sZtJZ tZt{s R I R% js I JZ? 8s $sj R ? st Y {YsR 7Z R$R t{$s R B B I sjj I R{BtB{$IB sZtJZ RBt {s}s{ R I RBR t YsR s Zts {s8$? Bt s }Zt B I } {$}$ s R }B Zt st RB{s%? Bt } BIZ{$IB s {BtR {Z t{$s I Zt 8B B 7Bt BjB j sI 8? sR I Zts st 4 -$A$j$IsI k {s}s{ R I sIY $ R t {ZsjJZ$ RZ} h{$ w} B R? - 8B JZ t s t {Bt s{ B ks JZ j R B I j Y$jB R {B8}B s {B8B Zts {Z Is tB 8sjD et j % R $IB I 7}$I 8st -$R t ZtBR I }? BR$ BR I {s}s{$IsI s}s t 8 t $j$8$ sIs R$ ZsIBR s js sj Z s I jsR 8ZK t {sR =ts } JZ K ts } R$? Bt 8ZR{Zjs RZj s RZh{$ t }s s JZ jsR js sK tsR R st jst9sIsR s st % jB{$IsI Ys{$s j BA` $%B j $IB *sIs js t BR$IsI {Bt js JZ RBt Z $j$9sIsR }B 7}$I 8st {sA } RZ}Bt j R Zts } B}$ IsI tB {Bt 8}jsIs }B jBR Z$Bt$R sR I j } RBts` U I A t R A$BI sIsAj R B sZ BI R Z$ R }sRsIB Zt {$ B $ 8}B 7$ tB R sR? ks 8 I$ ? st JZ$? t R t{s s I j$8}$s js {$ZIsI I R}Z? R I Zts jsR YsA$ Zsj R s% t Z sR I j RZ} Y? B IBtI tB Ysk %$K t s B R{ ts t JZ tB s}s 9{s RZ AZ ts s{$? Bt I js sK tsR VI 8? sR j RZ} Y? B I A ? s R}BtI I RZR s{{$Bt R st {$ZIsIstBR {Bt {Bt{$ t{$s {BjB $R s
n n
7Z} 8st Zt RZ} Y? B 8BI? j${B
VZtJZ RZ tB8A }s 9{s $tI${s jB {Bt s $B w{Bt s{{$? Bt I RZ} k 8st YB8A D j RZT } Y? B 8? sR {BtB{$IB k Ps8BRB I BIBR jBR $ 8}BR tB R I R 8ZtIB eR Zt - s R B $ $ts $B I j j `stB }jst s k} Bt 7$ tIB s? Zt Zt A A? R t%$sIB }B RZR }sI R s js q$ s }s s Rsj%s jB I j $t8$t t ht I RZ 8ZtIB ej } JZ K tB sjTej R sIB} sIB }B Zts Ps8$j$s jBR t JZ s }s I }Bt j {B8B tB8A ]js , jB IZ{s ? st t jBR %sjB R }s $BR tB s8T ${stBR Os sIZj B sR R ZI$s } $BI$R8B t s ? s s sAs`s {B8B }B B t j I$s $B qY *s$jk _jst s jsR B ? I t R I j R % B _ k GY$ IBtI {BtB{ ? s s NB$R Nst JZ$ t R ? s
© Los autores, 2001; © Edicions UPC, 2001.
d;;
* $t Bt s e$tR $t
RZ ts s8sIs V }s $ I t Bt{ R I {$I$ ? s $ $ R {B8B sj8s Z js I js YZ8st$IsI qB{sIB {Bt Zts % R $8 t s } B}$s I Zt YB8A Asjs I j {$ {B JZ R$ 8} jj %s I As`B I s t RZ B}s I {sjj sjTej\]js , t R {Bt% $ ?
7Z} 8st j YB8A I s{ B
eR RZ} Y? B 8BI jB k P t I jBR 8Z{YBR JZ j R Z$ ? st PZ { sIB }B F k 7$ j k FB 7YZR t d nM et{s ts BIsR jsR %$ ZI R k JZ$R$ BR -$ $Aj R s Zt } RBts` {B8}j sT 8 t t sIB s js jZ{Ys {Bt s j 8sj eR %sj BRB sR Z B $t j$ t _BR ZtBR j %sIBR %sjB R 8B sj R k ZtsR {Zsj$IsI R P? R${sR -{ }{$Btsj R 7ZR RZ} }BI R Z ?t${BR }s { t } BT { I I jsR I$P t R {BtI${$Bt R s8A$ t sj R I js q$ s 7? BjB R %Zjt sAj s Zts {BRsU js
, $} Bt$ s B $ $ts $s I j }jst s k} Bt {Bt JZ jBR 8sj%sIBR I Z tB $t t s ? st $t $8$Is jB s{Z IB {Bt js % R$? Bt {$t 8s B ? sh{s I d M * RI RZ s}s ${$? Bt js }B}Zjs $IsI I j } RBts` tB Ys Y {YB 8? sR JZ sZ8 t s * j {? B8${ }sRs ? s A$ t } Bt B s js j %$R$? Bt IBtI Ys {Bt sIB {Bt %s $sR R $ R w t d ;M d xn k d x D
7 s s I Zt 8s $sj JZ tB t %stB Ys s s% RsIB R $R sjs-$sR YsR s jj s s js q$ s I
sh{BR j Yst R Z$IB {Zs B $t{jZRB I I$AZ`BR st$8sIBR wd ;d k d EED V jBR R $sj R {$t 8s B ? js B8 s` RU yy qY VI% t Z ]Bt $tZ R d M(H $}B {B8B
7Z} 8st Ns } j? {Zjs >7Z} 8st qY B%$ d MH 7Z} 8st yy >7Z} 8st 7Z} 8st yyy >d MnH k 7Z} 8st yz et AZR{s I js }s9 JZ t{s ts s Zt `B% t 7Z} 8st t RZ s}s Zt$% R$ s $s {ZstIB s? Zt
>7Z} 8st yz Y +Z R PB _ s{ d M H ej } RBts` Ys {Bt sIB {Bt I $%sIBR I BIB
7Z} ABk
tB Ys I Rs BjjsIB }j ts8 t RZR }BI R O skZIst R I j $tB st$8sj {B8B
7Z} {sAsjjB
VI 8? sR I Zts ? }j${s P 8 t$ts
7Z} $ j
7Z} } B
B
Zt }s $ t JZ Ys RBA %$%$IB s js
I R Z{{$? Bt I j }jst s ts sj k} Bt e-$R t s8A$? t I$ tBR $8$ sIB R {B8B j
]s}$ ? st s % j B ]s}$ ? st s s%$jjsR
tB8A {Bt
j JZ s8A$? t R j {BtB{ ? s t tZ R B }s? R JZ % ? s js jZ9 t d ;( Ns }B}Zjs $IsI I R } RBts` jj ? B $t{jZRB s RZ} s s js I 7Z} 8st Z{, iB R k 3jsRY pB IBt j R $sj $jjk
NsR s% t Z sR I j ]s}$ ? st s s%$jjsR
et js ? }B{s I jBR R $sj R RBA >qY VI% t Z R
BP ]s} s$t s % j d ;dH Z%B Zt st ? -$ B 7 s sAs I Zt `B% t % tI IB I } $? BI${BR sR Bt JZ$ t {$A? s I 8stBR I Zt 8$R $BRB 8s B {$ BR }BI R {Bt js htsj$IsI I JZ jBR Z $j$9sR }s s Ys{ `ZR ${$s t j 8ZtIB ]Bt RBjB } BtZt{$s RZ tB8A
7Ys9s8
ws{ ? Bt$8B I 7sjB8? Bt <? {Zj R V jsR ZR VJZ$j R k {Z $BD sIJZ$ ? s sj $tR st jsR {Zsj$IsI R {s s{ ? R ${sR I jBR } RBts` R 8$ Bj? B ${BR {ZksR $t${$sj R PB 8st R s }sjsA s ej `B% t R {Bt% ? s t Bt{ R t Zt R {Bt j }BI I ZR j %sjB I VJZ$j R js PZ 9s I <? {Zj R js 8ZR{Zjs Z s I V jsR k js % jB{$IsI I {Z $B 7Z R? 8ABjB s j skB JZ jZ{? s t js } {Y s I RZ % R $8 t s _ B jBR RZ} }BI R sIJZ$ $IBR st R? BjB 8}B sj R q stR{Z $IsR ZtsR YB sR %Bj%? s s R Zt YZ8stB tB 8sj Ns $t tZ$IsI I RZR s% t Z sR k js s8}j$s sj ? s I %$jjstBR {Bt j 8sj%sIB k R$t$ R B
eR{B }$? Bt
s js {sA 9s Ys{ t I R
RZ} Y? B Zt } RBts` } {Zj$s {ZkBR }BI R tBR sAR tI 8BR I stsj$9s YsA$Is {Z t s I jB I$%$tB I RZ } B{ I t{$s WsI$ R$t 8As B Ys }BI$IB Ys{ tZt{s RB8A s sj RZ} Y? B }B -{ j t{$s 7Z} 8st JZ$ t $t{jZRB t j 8ZtIB sj sts ? s Zts As sjjs 8? sRU s{ZRsIBR I }js $B jBR { sIB R I j ]s}$ ? st s % j w $jj 3sb{ k ] ] {$ {Zjs{$? Bt t d xn {,D I A$ Bt $ s jB I js
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
d;x
7Z} PZ 9s
zs8BR s }sRs s {Bt $tZs{$? Bt sj ZtsR I jsR YsA$j$IsI R JZ Ys{ t I 7Z} 8st j RZT } Y? B 8? sR sI8$ sIB k 8$IB ]B8B RZR {Bt ? t R RZ} Y B${BR 7Z} 8st R s8A$? t IsIB s %$Bjs js { s j k I W b Bt k j } $t{$}$B I {BtR %s{$? Bt I js {st $IsI I 8B%$8$ t B V? Zt s{ } stIB RZ RZ} PZ 9s jB {$ B R JZ RZR Ys9sK tsR R R tB R ? st t$ 8Z{YB 8 tBR {B8B tBR jsR }$t st z s8BR Zt }s I ` 8}jBR _s s IZ{$ jBR P { BR I Zts -}jBR$? Bt tZ{j s JZ Ys } BIZ{$IB %$Bj t BR 8B%$8$ t BR I $ s s jB js B I js Psjjs I 7st VtI ? R t ]sj$PB t$s 7Z} 8st t js } j? {Zjs YB8? Bt$8s j %st s Zt tB 8 } Is9B I B{s I {$ t BR I 8$j R sj % 9 8$jjBt R I Bt jsIsR 7$t t s s I$R{Z $ j B $ t I js RZ} PZ 9s t { Rs $s }s s jj %s s {sAB Zts } B 9s {B8B ? R s jB {$ B R JZ }B 8Z{YB 8} K tB JZ j }Bt s sj sRZt B R ? s $t{s}s9 I {BtR Z$ jB Ns PZ 9s ` {$Is }B j RZ} Y? B R t %$ ZI I js { s j k I W b Bt $ Zsj s js JZ ` { RBA ? j 8$R8B j AjBJZ B{BRB k }B st B $ Zsj s js JZ sj$9st RZR RZ} }$ R RBA j RZ jB ]Bt BIs R Z $IsI j RZ jB tB RB}B s ? s j } RB I j {$ sIB AjBJZ ej RZ} Y? B % ? s {B8B j RZ jB R YZtI As`B RZR }$ R k R 8}Z`sIB $ s sI t BU js IZ{$Is RZ} h{$ w}jst s I jBR }$ RD t JZ R }s R tB 8 } RB B $ $ts Zts } R$? Bt wPZ 9s }B Zt$IsI I RZ} h{$ D $8}BR$Aj I RB}B s }B j tB eR s R$ Zs{$? Bt }Z I {Bt 8}js R s8A$? t I RI j }Zt B I %$R s I js {BtR %s{$? Bt I js {st $IsI I 8B%$8$ t B 7$ 7Z} 8st j %st s Zts st 8sRs s Zts {$ s % jB{$IsI RZ {Z }B I 8sRs 8Z{Y? R$8B $tP $B R ? s $8} j$IB t js 8$R8s I$ {{$? Bt } B t R t $IB {Bt s $B s Zts st % jB{$IsI ]BtR$I stIB JZ RZ RZ} {Z }B 8st $ t js $ $I 9 R % ? s $ 8$R$Aj 8 t YZtI$IB Ys{$s jsR t sK tsR I js q$ s eR sj B }s {$IB s jB JZ RZ{ I {ZstIB R } tI {js%s Zt {js%B t js 8sI s ej 8s $jjB {Bt JZ R Bj} s j {js%B stRh s ? R RZ {st $IsI I 8B%$8$ t B jB JZ Zt$IB s js IZ{$Is RZ} h{$ I RZ }Zt s } 8$ JZ } t {Bt Ps{$j$IsI et Zts %$K t s {B R}BtI$ t s ZtB I jBR {? B8${R JZ $ t t {B8B } B s Bt$R s sj YB8A I s{ B }Z I %? R j }jst sIB t 8 I$B I Zts {s s 7$t 8? sR JZ R $ s RZ }BI BRB RZ} A s9B {BtR$ Z }s s Zt {s8$? Bt JZ Z Is }B js 8$R8s w3$ n MD VYB s js PZ 9s JZ sj$9s 7Z} 8st $ t js I$ {{$? Bt YB $9Bt sj Os JZ RZR }$ R tB Yst {YsIB s? { R t j RZ jB js PZ 9s 8? s-$8s JZ }Z I sj$9s %$ t IsIs }B j B9s8$ t B t RZR }$ R k j }s%$8 t B eR s PZ 9s R } B}B {$Btsj s RZ } RB k I } tI I j {B h{$ t I P ${{$? Bt t js RZ js I RZ {sj9sIB k j sRPsj B I js {s s 7$ B8s8BR Zt %sjB I j B I t I js Zt$IsI }s s R {B h{$ t k {BtR$I s8BR JZ js 8sRs I 7Z} 8st BtIs jBR ( , w sj k {B8B j } B}$B RZ} Y? B I R% js t js } j? {Zjs I d MD R $8s8BR t MM( W js PZ 9s 8? s-$8s ` {$Is }B j RZ} Y? B eR s PZ 9s I P tsIB JZ s{ ? Zs RBA j {s8$? Bt JZ {BtR$I s8BR $ t Zts 8sRs I x( Bt jsIsR k R I R}js9s s d(( ,8bY } B%B{s JZ RZ % jB{$IsI I$R8$tZks s Zt $ 8B I (, (1 8bR {sIs R ZtIB 7Z}Bt$ tIB JZ j RZ} Y? B RBA %$% s js {Bj$R$? Bt wsj B P? s{$j I sRZ8$ s R sR sj Z sRD j R}s{$B {B $IB }B j R$R 8s RZ} Y? B T{s8$? Bt st R I }s s R R ? s gZtBR 1( ,8 _ R s RZR }BI R g7Z} 8st tB }BI ? s %$ s R s sR sIB R s I$R st{$s st R I jB s RZ {B8 $IBU }s s }B {B8}j B j {s8$? Bt Vj B I$P? {$j I s{ } s }B sJZ jjBR $t{BtI${$Btsj R I j RZ} Y? B I R BRBR I s{{$Bt R }$Ist R }Z R B JZ s8sK ts } B 9s tI ? s jZ s t sj B 8 tBR I 1x 8$tZ BR 7 {B8} tI t Bt{ R JZ jBR Z$Bt$R sR Yskst t$IB s A$ t sYB s tBR ZtsR R{ tsR Zt st B sAZ $IsR O t{$8s j RZ} Y? B I A
© Los autores, 2001; © Edicions UPC, 2001.
d;E
* $t Bt s e$tR $t
Is s{$sR s js -$R t{$s I Zts PZ 9s {B8B j B9s8$ t B et sZR t{$s } ? s{ ${s I j 8$R8B w}B ` 8}jB t j {sRB I JZ js s{{$? Bt YZA$ R t$IB jZ s t Zts RZ} h{$ I Y$ jB IBtI j {B h{$ t I B9s8$ t B R ZtsR % $t % { R $tP $B sj JZ Y 8BR {BtR$I sIBD 7Z} 8st s IZ sR } tsR YZA$ R }BI$IB I t j % Y? {ZjB ]js B JZ R$ 8} JZ Is ? s sj Z$ t JZ }$ tR JZ sj $ Zsj JZ js % R $8 t s I j RZ} YB8A j } 8$ %Bjs s{$sR s Zt 8 {st$R8B I R{BtB{$IB j {sj9sIB R ? s Y {YB I Zt 8s $sj R} {$sj w} B{ I t sj % 9 I k} BtD {ZkB {B h{$ t I B9s8$ t B {Bt j RZ jB }Z I 8BI$h{s R s %BjZt sI k t R$ Zs{$Bt R - 8sR {B8B js {B8 t sIs R s 8Zk RZ} $B * R 8$j % { R 8skB 7Z} 8st I tI ? s sj {s8$? Bt t Zts I$R st{$s 8? sR Bj sAj I 1x 8 eR Zts Rsj$Is s9BtsAj JZ j R JZ Is s jBR Z$Bt$R sR }s s Rsj%s js R{ ts VZtJZ t {ZsjJZ$ {sRB 5JZ? 8 I${ t I j {sjB t sIB IZ st js P ${{$? Bt2 57 ? s I$R$}sIB }B RZ % R $8 t s2 5VZ8 t s ? s RZ 8} s Z s {B }B sj {B8B RZ{ I? s t j {sRB I 3jsRY2 WB R? BjB jsR Ys9sK tsR I js h{{$? Bt {B8B js {B8 t sIs k B sR JZ Y 8BR stsj$9sIB t s}s sIBR } { I t R tB tI ? st jZ s R$ j B9s8$ t B tB -$R $ R qs8}B{B RZ{ I ? st 8Z{YBR I jBR P t? B8 tBR B I$ts $BR s jBR JZ R s8BR s{BR Z8A sIBR _ R s RZj s } `ZI${$sj t j PZt{$Bts8$ t B I jsR 8? sJZ$tsR }B j I R sR k jsR }? I$IsR t ? ${sR JZ {Btjj %s R s PZ 9s } B}B {$Bts R sA$j$IsI _ 8$ {s8$ts }B js {sjj B {BtIZ{$ Zt sZ B8? B%$j e%$ s JZ jBR AB Bt R R {s$ st k JZ jBR {ZsI BR {Bj sIBR I jsR }s I R R } {$}$ t s $ s k }B ` 8}jB }BR$A$j$ s JZ jBR {B IBt R I jBR 9s}s BR R 8st t st stZIsIBR et js tB% js =t st$jjB sj I IB I j 7Bj >i$t V BZtI Y 7Zt d x1H ]j$&B I * 7$8s, I R{ $A Zts RB{$ IsI I {BtRZ8B {B8B js tZ R s IBtI Zts }Z s sA$ s s B s I$8 tR$? Bt Ys{ }BR$Aj js -$R t{$s sJZ$tsR I sP $ s AB8A$jjsR t{ tI IB R sZ B8? B%$j R { D R I {$ I } BIZ{ BR tBR w8? JZ tB R I R sR st }B js P ${{$? Bt t$ R R B} st {Bt j ZRB 5_Z I t ZR I R $8s $ts js { $R$R JZ } B%B{s ? st t tZ R B t B tB {BtRZ8$R s js s}s ${$? Bt I sj R } BIZ{ BR2 qs8A$? t t js } j? {Zjs ej YB8A I j s` Ajst{B >qY st $t Y GY$ 7Z$ d xdH R -}jB st jsR {BtR {Z t{$sR I Zts $ttB%s{$? Bt %BjZ{$Bts $s JZ jBR }BI BRBR 8} Rs $BR I j 8$B tB R ? st I$R}Z R BR s sRZ8$ U Zt `$IB }s s js PsA ${s{$? Bt I % R $IBR tBR V? Zt %s 8? sR sjj? s *s%$I $t t RZ tB% js ej P { B } ? s{ ${s >qY _ s{ ${ e& { d M;H et jjs Zt } BP RB I P? R${s * tt$R WZ j RZj s stR}B sIB s Zt 8ZtIB sj ts $%B IBtI jBR BA` BR 8 `B st {Bt j ZRB t jZ s I I $B s R Ns s{{$? Bt t R? R I tB8$ts } s{ ${s NBR % R $IBR I A t Z $j$9s R }s s JZ 8 `B t I sR} { B jsR s 8sR ZRs R }s s {Bt% $ R t } P { sR ej P { B } ? s{ ${s } B%B{s P t? B8 tBR {Z $BRBRU jBR 8st$JZ? R I jBR R{s}s s R RBt {sIs % 9 8? sR } P { BR ej I R sR JZ R ? Zt j sZ B } B%B{s js R$8}j 8$ sIs I jBR stR ? Zt R R$ % }s s 8 `B s RZ sR} { B ej P { B {Btjj %s }B {Bt s js }? I$Is I j R}? $ Z { s $%B k Zts $t%BjZ{$? Bt RB{$sj 5_s s JZ? { s sj B tZ %B R$ AsR s } s{ ${s {Bt jB {BtB{$IB }s s BA t Z tR$j$BR 8 `B sIBR2 5zBjs 2 g_ B R$ R 8Zk P? s{$j
yt{jZRB 8? sR JZ js RZ} PZ 9s js {s}s{$IsI I %Bjs R Zts I jsR {s s{ ? R ${sR } $t{$}sj R I 7Z} 8st Ns } Zt s R BA%$s 5{? B8B jB Ys{ 2 Nst{ 8BR sj ZtsR Y$}? B R$R
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
d;
3$ n M 5]BtR Z$ ? s 7Z} 8st RZ } B}? BR$ B2
ks Y 8BR $tI${sIB jsR I$P t{$sR I jsR {BtI${$Bt R P? R${sR t RZ }jst s I B $ t k} Bt k j I sIB}{$? Bt js q$ s }s { t R s t j B $ t I jBR }BI R I R RZ} Y? B _BI ? s8BR } tRs JZ js s% IsI t sJZ j }jst s R RZ} $B s js R k JZ j {Z }B I j {$? t ts{$IB sjTej R ? s } }s sIB }s s sIs} s R s js %$Is t R 8ZtIB ]B8B {BtR {Z t{$s I jjB sj I Rs Bjjs R t js q$ s RZ PB sj 9s P? R${s R 8Zk RZ} $B s js I Zt R YZ8stB eR R JZ t RZ I Rs}s {$IB 8ZtIB tB }sRs ? s I R Zt , $} Bt$stB {B8? Zt R t js q$ s Zt RZ} PB 9ZIB VR? s{$sR s js I$P t s% IsI 7Z} 8st }Z I sj$9s stI R Rsj BR k j %s R $t{jZRB }B t{$8s I jBR I$h{$BR Vj B }s {$IB s jB JZ jBR sR BtsZ sR -} $8 t st t jZ s R {B8B js NZts IBtI js s% IsI R Zts R - s }s I js s% IsI t js RZ} h{$ R k {Bt Zt $8}ZjRB R$8$js }BI ? st Rsj s BAR ? s{ZjBR R $R % { R 8? sR sj BR JZ t js q$ s eR s -}j${s{$? Bt R {B R}BtI {Bt j } $8$ $%B 7Z} 8st I j {? B8${ j {Zsj 8? sR JZ %Bjs jB JZ Ys{? s s $ IstIB Rsj BR 7$t 8As B {B8B }Z I RZ}Bt R Zts {BRs R Rsj s 8Zk sj B k B s 8Zk I$R $t s R t }j tB Rsj B I$ $ $ R Ys{$s sI jst B Ys{$s s ? sR s %BjZt sI gB }s s R t }j tB %Z jB yt{jZRB B8stIB t {BtR$I s{$? Bt R s YsA$j$IsI }s s P { Zs stI R Rsj BR tZ R B RZT } Y? B I A ? s RZ} s s% R BAR ? s{ZjBR NBR st$8sj R Rsj st 4 -$BtstIB k - tI$ tIB ? s}$Is8 t RZR - 8$IsI R wsZtJZ jBR $tR { BR }B ` 8}jB Z $j$9st Zts R} {$ I P { B Bt {s s}Zj sD ej } B{ RB I Rsj B $ t IBR PsR R et js } $8 s I tB8$tsIs PsR I j %s{$? j st$8sj R } }s s }s s Rsj s 4 -$BtstIB jsR }s sR Zts {$ s I$R st{$s wI$R st{$s I s{ j T s{$? BtD {s s{ ? R ${s I j st$8sj _s s j YB8A R s I$R st{$s R I j B I t I ( x 8 8$ t sR JZ }s s j {st Z B k js }Zj s R I d 8 k ( M 88 R} { $%s8 t V {Bt $tZs{$? Bt - $ tI jsR }s sR ? s}$Is8 t }sRstIB I j }BRB s js % jB{$IsI I j %s{$? Bt Ns R ZtIs PsR 8}$ 9s {ZstIB j st$8sj {Bt jsR }s sR A$ t - tI$IsR I `s I B{s j RZ jB k R j %s _s s Zt Bt I j %s{$? Bt YB8A tB 8sj js % jB{$IsI I j %s{$? Bt R I j B I t I ; ; 8 R k js s{ j s{$? R 1 % { R RZ} $B s js s% IsI Ns sj Z s 8? s-$8s sj{st9sIs t Zt Rsj B % ${sj R I j B I t , , , b
6 ]B8B
d;M
* $t Bt s e$tR $t
I d 8 _s s Rsj s Zts sj Z s 8skB I A ? s sZ8 t s R js s{ j s{$? Bt I j %s{$? Bt 7$ j YB8A }ZI$ R Rsj s {Bt js 8$R8s s{ j s{$? Bt {Bt JZ jB Ys{ Zts }Zj s }BI ? s sj{st9s js PB 8$IsAj sj Z s I E1, x 8 } B jBR } BAj 8sR hR$Bj? B ${BR I $%sIBR I js -}BR${$? Bt I ZjB 1D j$8$ s ? st jsR }BR$A$j$IsI R I I$RP Z s I sj RZ {Z }B s Zts st s{ j s{$? Bt w]s}? Ys9sK ts _s s P { Zs Zt Rsj B I 8skB j %s{$? Bt JZ js YsA$ Zsj R$t {Z $ s Zt sZ8 t B -{ R$%B I js s{ j s{$? Bt YsA ? s JZ $8$ s j I$R K tB R Z{ Z sj I jsR }s sR I jBR {st Z BR eR BR {BtB{$IBR Rsj sIB R }BR t Zt sj? Bt I VJZ$j R stI k Z RB JZ R {B8}B s {B8B Zt 8Z jj s{$sR sj {Zsj }Z I t sj{st9s sj Z sR I YsR s 1, 8 t Rsj B % ${sj R$t JZ $ I$R st{$sR I s{ j s{$? Bt 8Z{YB 8skB R JZ jsR I Zt YB8A NsR A$ t } B}B {$BtsIsR PB T 8sR I j {Z }B I 7Z} 8st tB RZ $ t R s 8BI$h{s{$? Bt I js R Z{ Z s I RZR - 8$IsI R $tP $B R 6 7$ I `s8BR s Zt jsIB B sR -}j${s{$Bt R I j BIB $t% BR? 8$j R {B8B j ZRB I Zt 8s $sj BtD R? BjB tBR JZ Is {Bt{jZ$ JZ st $ s%$ s B $B B js j %s{$? Bt }B %BjZt sI } B}$s wj %$ s{$? 7Z} 8st %Z js s{$sR s JZ RZ % R $IB s{ ? Zs {B8B 8 I$B I } B}ZjR$? Bt 7$t 8As B s I$P t{$s I B BR YB8A T{BY {B8B iB{, JZ 8Z R st ZtsR s}s s BRsR 8B{Y$jsR } B}ZjRB sR js % R $8 t s I 7Z} 8st tB }s { R{BtI t$t ? Zt s $jZ $B 5qsj % 9 R Ysjjs B{Zj B I As`B I RZ {s}s2 qs8}B{B 8$ {YB BR I sR t$ tsIs }B j R $jB VR? JZ tB t{Bt s8BR t$t Zts -}j${s{$? Bt sj 8 {st$R8B JZ } 8$ sj RZ} Y? B %Bjs 57 st$8s j { B s 8$ $ sj Zts Y$}? B R$R2
Ns j k tIs $ s I ? y{s B k *? IsjB $jZR s js $8}B t{$s I j YB8A }s s }BI %Bjs {B8B jsR s% R qsj % 9 {BtR{$ t R I R s j$8$ s{$? Bt js {$ t{$s h{{$? Bt Ys sAB IsIB t {Bt sIsR B{sR$Bt R j 8s et js tB% js VjsR tB{ Z tsR >W$ Y b$t R d EMH I iBA 7$j% A jBR R R YZ8stBR Yst I Rs BjjsIB sjsR {B8B jBR }? s`s BR VZtJZ }s s t{Bt s s R R YZ8stB$I R %BjsIB R Ysk JZ $ R s B BR }jst sR V}s { t {Bt }jZ8sR k BIB t pZ s I sjsIBR >qY Gs BP Y G$t T t d nH k ej }Z AjB I j s$ >qY _ B}j BP Y G$tI d nH I _BZj VtI RBt qs8A$? t t 3jsRY pB IBt t{Bt s8BR Zts s9s I YB8A R sjsIBRU jBR YB8A R Ysj{? Bt B $ $ts $BR I j $tB I V A? B s t j }jst s Bt B 5+Z? PB 8s I A ? s t Zt YB8A T}? s`s B {ZkBR 8? ZR{ZjBR I Rs BjjsR t Zts }B t{$s } B}B {$Btsj s RZ s8sK tB $ Zsj s js I Zt s ? Z$js }B ` 8}jB2 5]? B8B I A ? s R RZ ? B s- }s s sjB`s jBR 8? ZR{ZjBR I RZR sjsR2 5O RZR }$ tsR }s s {BtR Z$ IZ{$ j } RB2 ej hR$? BjB B FBYt 7 <sjIst Ys {sj{ZjsIB JZ Zt YB8A %BjsIB t { R$ s ? s Zt } {YB I d, 1 8 I BRB R? BjB }s s sjB`s jBR 8? ZR{ZjBR I RZR sjsR 7ZR }$ tsR sI 8? sR I A ? st {Bt% $ R t 9st{BR 8Zk I j sIBR }s s sYB s } RB eR sR {s s{ ? R ${sR }Bt t t js I `Z${$B js }BR$A$j$IsI I JZ R R YZ8stB$I R sjsIBR {B8B jBR {$ sIBR }Z Ist %Bjs }B RZR } B}$BR 8 I$BR }B jB 8 tBR R$ jsR Bt wYZ RBRD tB RZj st 8BI$h{sIsR {BtI${$Bt R P? R${sR w s% IsI s$ D B I {BtR $ Z{$? =ts I R{ $}{$? Bt {BY t I js PB 8s I { $s Z sR %BjsIB sR js t 8BR t js tB% js * R} s >qY Vbs, t R d 1H I 7Y $ 7 q }} 7 s s I jBR zBjsIB R YsA$ st R I j I$R st }jst s ZtIB I j i? BU "NsR }s sR js sR k {sR$ YZ8stsR {Bt RZR }$ R t PB 8s I s sR {ZA$ sR I }jZ8sR jsR sjsR }j sIsR {ZksR }Zt sR {sR$ B{sAst j RZ jB jsR 8stBR I R I IBR JZ ts{? st t js 8ZK t {s V I$P t{$s I jBR } JZ K tBR %BjsIB R t RZ BR B j }${B tB s js B R$tB {Ys B }B jB JZ I } hj YZA$ R }s {$IB {sR$ YZ8stB I tB R }B js
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
d;
Empuje =
1 CL dV 2 S 2
3$ n i {B Is jBR } $t{$}$BR P? R${BR JZ $t %$ t t t j } B{ RBU 5Zt R t{$jjB 8? BIB }s s %Bjs 2 sZR t{$s I ts $9 } ts{YBR t jsR B `sR B`BR stI R IBtIBR k BI sIBR I }jZ8sR j } {YB } B8$t t t j { t B k j {Z jjB JZ tB s 8Zk js B } B JZ R - tI? s }s s %Bjs " Ns PZ 9s I RZR t s{$? Bt JZ s{ ? Zs RBA Zt sjs R } B}B {$Btsj s js RZ} h{$ I js 8$R8s s js I tR$IsI I j 4Z$IB ws$ D k sj {ZsI sIB I js % jB{$IsI js $%s I j 4Z$IB R} { B I j BA` B ej {B h{$ t I } B}B {$Btsj$IsI R I tB8$ts {B h{$ t I RZR t s{$? Bt k $ t JZ % {Bt js PB 8s I j sjs k j s ?t ZjB PB 8sIB }B js I$ {{$? Bt I j 4Z`B I s$ k j sjs jjs8sIB ? st ZjB I s sJZ _s s %Z jBR P { ZsIBR s sj Z s {BtR st js PZ 9s I RZR t s{$? Bt R $ Zsj sj } RB I j BA` B %BjsIB NBR s%$Bt R s s{{$? Bt }B ` 8}jB R 8Z % t s stI R % jB{$IsI R I 8st s JZ js RZ} h{$ I RZR sjsR k j s ?t ZjB I s sJZ }Z I t R } JZ K tBR et {s8A$B t { R$ st sj{st9s Zts st % jB{$IsI }s s }BI j %s R _s s I R} s s % jB{$IsI R 8BI sIsR sj {B8B jB Ys{ Zt s%$? Bt I }sRs` BR R t { Rs $B Zt sZ8 t B A ZR{B I j s ?t ZjB I s sJZ Zts % 9 sj{st9sIs Zts {$ s % jB{$IsI { ? ${s NBR s%$Bt R s Y? j${ %Z jst s % jB{$IsI R $tP $B R k }BR t sjsR k s ?t ZjBR I s sJZ } B}B {$Btsj8 t 8? sR stI R JZ jBR s%$Bt R s s{{$? Bt et j {sRB I jBR st$8sj R %BjsIB R jsR sjsR {BtR $ Zk t s js % 9 jBR 8 {st$R8BR I } B}ZjR$? Bt k I RZR t s{$? Bt eR B Ys{ JZ RZ 8B%$8$ t B R s I Zts st {B8}j `$IsI Ns PZ 9s I RZR t s{$? Bt R$ Z R$ tIB PZtIs8 t sj sZtJZ st B j {B h{$ t I RZR t s{$? Bt {B8B js RZ} h{$ k js % jB{$IsI %s ? st t jsR I$P t R PsR R I j 8B%$8$ t B * `stIB s Zt jsIB j I R{BtB{$IB 8 {st$R8B Z $j$9sIB }B 7Z} 8st }s s %Bjs k sRZ8$ tIB I 8st s $8}j? {$ s sj ZtsR R$8}j$h{s{$Bt R }BI 8BR P { Zs Zt R t{$jjB {? sj{ZjB }s s I 8$ts js % jB{$IsI 8? t$8s JZ t { R$ s sj{st9s tZ R B RZ} Y? B }s s %Bjs _s s jjB AsR s {Bt $ Zsjs j } RB s js PZ 9s I RZR t s{$? Bt w ` {$Is }B j 8 {st$R8B } B}ZjRB D k Ysjjs js % jB{$IsI 7$ R sRZ8 t %sjB R ? }${BR {BtB{$IBR }s s jsR 8s t$ ZI R P? R${sR JZ $t %$ t t t j } BAj 8s w8sRs I 7Z} 8st k I tR$IsI I j s$ D k R RZ}Bt t %sjB R s9BtsAj R }s s j
© Los autores, 2001; © Edicions UPC, 2001.
@N
* $t Bt s e$tR $t
R B w{B h{$ t I RZR t s{$? Bt k RZ} h{$ I js {s}sD Ysjjs8BR JZ 7Z} 8st I A 8B% R s Zts % jB{$IsI 8? t$8s I 1;E ,8bY 7$ t{$8s } tI I R} s jj %stIB {BtR$ B j } RB sI${$Btsj I }B ` 8}jB NB$R Nst RZ } B8 $Is I A ? s {B }B j RZ jB YsR s sj{st9s Bt js % jB{$IsI ZtBR n( ,8bY WsIs JZ j RZ} YB8A tB }Z Is {BtR Z$ et {B8}s s{$? js % jB{$IsI R I$ { s8 t } B}B {$Btsj s js s? 9 {ZsI sIs I j s8sK tB =t s% } JZ K ts }Z I sj{st9s R s % jB{$IsI R$t 8? sR JZ Is Zt Rsj B k Zt }s I sj BR =t s% stI sIJZ$ js % jB{$IsI t { Rs $s {B $ tIB }B j RZ jB B }B t{$8s I j s Zs ej s% R Z9 }BR Zt s8sK tB {s s{ ? R ${B 1x % { R RZ} $B sj I j % t{ `B WB I A RB } tI tBR JZ Zt s% {B8B ? R s tB }Z Is %Bjs _ R s R Zt AZ t {B IB wsj{st9s {Bt Ps{$j$IsI Zts % jB{$IsI }Zt s I t$8s t { Rs $s }s s j %st s R t %Z jB j RZj s $tsj{st9sAj VR? 1 ,8bYD js % jB{$IsI 8? Zt s% I st s8sK tB I A s} B% {Ys jsR {B $ t R I s$ sR{ tI t }s s 8st t R t %Z jB et tZ R BR I? sR j st$8sj %BjsIB 8? sR stI R j sjAs BR {Bt Zts t% sIZ s I sjsR I ZtBR n, x 8 k Zt } RB I d( , et js ? }B{s I jBR I$tBRsZ $BR -$R $ Bt } $j R %BjsIB R s? Zt 8skB R {B8B j 8? t$8s I %Z jB I Zt s% {B8B j % t{ `B R I ZtBR 1d ,8bY et Zt %Z jB s sj Z s {BtR st
} BRsZ B I 8? sR I dd 8 I s8sK tB k Zt } RB I dM ,
eR sR
{ $s Z sR I R{B8Ztsj R tB }BI? st I R} s {B $ tIB k As $ tIB R$8}j 8 t RZR sjsR _s s %Bjs R jst9sAst I RI s{st $jsIBR k s} B% {YsAst jsR {B $ t R sR{ tI t R I s$ {sj$ t
NBR 8? ${BR I s Bt R RBt s8A$? t { $s Z sR JZ }B RZR stI R I$8 tR$Bt R tB }BI ? st %Bjs N R Ys ? s Psj s Zts 8ZR{Zjs Z s 8skB }s s sj9s j %Z jB I js JZ }BR$Aj 8 t }BI ? st {Bt t t RZR ks %BjZ8$tBRBR {B }s{YBt R _ R s jjB s? Zt }Z I %? R j R { Z9stIB {$ jBR $8s $ts $BR B R$ %$ tIB {B8B 8 I$B I stR}B t } j? {ZjsR k tB% jsR $JZ sIsR As`B j tB8A I
Pst sR? s
7$ %st s 8BIB I ` 8}jB js } j? {Zjs
Rjsk d MdH j {? B8${
_ t
ej { ts $B
I z${ t 7 jj R k js R $ I tB% jsR
ej I s ? Bt I j js B I PZ B >* s BtT NBR * s Bt R I
>d E Td M H { sIs }B js R{ $ B s Vtt {]s& k et R s Rs s tBR t{Bt s8BR {Bt
ZtBR I s Bt R %BjsIB R j? }s sR YsA$ st R I j }jst s _ t NBR R R YZ8stBR } B{ I t R I js q$ s JZ sK tBR Ys {BjBt$9s Bt j }jst s R sAj { t {Bt R sR { $s Z sR Zts sj$st9s }s s Ys{ P t s js $t%sR$? Bt I Zts }js s sj$ t? ts I R}B sR NBR I s Bt R }Z I t s s{s jsR R ${sR JZ R s $AZk t s R BR Pst ? sR ${BR R}B sR {Bt j PZ B JZ -Ysjst wB s I jsR {s s{ ? R RD k %$ s sR? JZ s s$ Z t t js RZ} h{$ I I${YB }jst s Ns $8}BR$A$j$IsI }s s sj9s j %Z jB }B }s I R BR R R Ys {BtIZ{$IB s sj ZtBR R{ $ B R s $8s $ts {Bt Zt {$ B BJZ $ ? Bt${B s jBR I s Bt R {B8B { $s Z sR j$ sR jj tsR I sR JZ 4B st {B8B R$ R s sR I stI R I$ $ $Aj R
FZt B s jBR I s Bt R k {B8}s $ tIB js {s B ? s I R R 8$ Bj? B ${BR t 8BR s8A$? t sj PsAZjBRB }? s`s B iB{ I R{ $ B }B j %$s` B s {B _BjBU "NBR YsA$ st R I js $Rjs I sIsT sR{s h t JZ t I 8$tsIs R s{$? Bt I j sK tB jj s I jsR $Bt R sZR sj R Zts R} {$ - sB I$ts $s I }? s`s B JZ I tB8$tst iB{ 7Z PB 8s R R 8 `st s js I j s ? Z$js } B R $t{B8}s sAj 8 t 8? sR stI ej iB{ R st PZ JZ }Z I $9s {Bt RZR s sR Zt j Pst %Bjs {Bt ? j }B jBR s$ R k I `s jB {s I RI j }Zt B 8? sR sj B }s s I %B s jB I R}Z? R NBR JZ Yst %$R B sj iB{ sR Z st JZ jsR sjsR 8$I t I$ {$R$ }sRBR I }Zt s s }Zt s k JZ jsR }jZ8sR Ys{ t B{YB }sRBR I jBt $ ZI" et js } j? {Zjs
7$8AsI j 8s $tB
>7$8AsI Y 7s$jB
d ; H s}s { Zts I R sR s% R JZ j $t ? }$IB } B s Bt$R s Z $j$9s {B8B 8 I$B I stR}B }s s RZA$ s js {$8s I Zts 8Bt sK ts {Bj ? stIBR {Bt RZ Z Ast I Zts I RZR }s sR $ stT
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
@N@
R{sR R$t JZ j st$8sj R I {Z t s eR s s% $8s $ts $s }BI ? s t js{$? Bt {Bt j - $t B
}? s`s B j Pst
JZ YsA$ ? B sj8 t t js $Rjs I sIs sR{s YsR s JZ PZ - 8$tsIs s
8 I$sIBR I j R$ jB zyy VZtJZ $t{s}s9 I %Bjs IsIs RZ t% sIZ s wRZR ;x( , I } RB Ys{ t I jjs j s% 8? sR } RsIs JZ `s8? sR Ysks -$R $IBD tB I A - sK ts JZ sIJZ$ $ R j {s ? s{ I s% 8? ${s
]BtR$I s{$Bt R RBA js }B t{$s JZ R JZ$ }s s %Bjs s Zts I 8$tsIs % jB{$IsI } 8$ t Is Zts R $8s{$? Bt s{ {s I j s8sK tB 8? s-$8B JZ }Z I t Zt st$8sj %BjsIB WB -$R t st$8sj R %BjsIB R 8Zk stI R sZtJZ s8}B{B jBR Ysk 8Zk } JZ K tBR Vj ZtBR $tR { BR I$8$tZ BR I js R} {$ I jsR 8BR{sR k jsR s%$R}sR I YsR s d 8$j$ s8B I } RB RBt -{ j t R %BjsIB R ytI$%$IZBR I s8sK tB $tP $B tI ? st 8Z{YBR } BAj 8sR }s s {Bt Bjs RZR I R}js9s8$ t BR s? BR ks JZ R % ? st s 8 { I I {ZsjJZ$ {B $ t I s$ WB RBt %BjsIB R t R t $IB R ${ B Ns {B s $tP $B }s s j } RB I Zt st$8sj %BjsIB R Ys R sAj {$IB t js I? {$8s I 8$j$ s8B k Zt 8$j$ s8B $ t sR JZ js {B s RZ} $B R Ysjjs ? s t jBR dx k 1( ,$jBR NBR ( , I 7Z} 8st j R$ ? Zst PZ s I j $t %sjB R %sIB s jBR R R JZ %Z jst }B RZR } B}$BR 8 I$BR ! B sR} { B I j %Z jB JZ $ t JZ % {Bt jsR I$8 tR$Bt R R j I j As $IB I jsR sjsR Ns P {Z t{$s I As $IB I } tI I j s8sK tB I j st$8sj =ts 8BR{s 8Z % RZR sjsR d (;E % { R {sIs R ZtIB Zts sA `s jB Ys{ 1n( % { R Zt {Bj$A ? d(( Zt }? s`s B {B8? Zt dx Zts {$ [ Z K ts IBR B R % { R 8$ t sR JZ Zt {? BtIB tB sj{st9s s sj s t$ Zts % 9 IZ st R $ 8}B NsR s% R 8? sR stI R {B8B j sjAs BR j AZ$ B j {? BtIB }jst st R$ 8} JZ j R R }BR$Aj ks JZ j sj B {Bt $tZsIB j R } R t s Zts st RPZ 9B _B jB 8 tBR jsR {s s{ ? R ${sR I j %Z jB I 7Z} 8st }s { t R s I s{Z IB {Bt R s j k I R{sjsU j RZ} Y? B {ZkB s8sK tB R ? s 8? sR { {s I jsR stI R s% R JZ I jBR } JZ K tBR R R %BjsIB R tB 8Z % s $As k sAs`B RZR A s9BR t$ s8}B{B RZ {s}s {ZstIB %Z js
* R}Z? R I jB I${YB k s } Rs I jBR } BAj 8sR ks R K tsjsIBR jBR YB8A RT{BY {B8B iB{, T RZj st 8Z{YB 8? sR { ? Aj R JZ 7Z} 8st R$ I RZ {s jBR s$ R R s s ej R} { s{Zjs I Rs BjjB I js s%$s{$? Bt JZ Ys } 8$ $IB RZ} s jsR j$8$ s{$Bt R P? R${sR I j YB8A s{$sR sj s%st{ {tBj? B ${B Ys RZ}j$IB s AsR I $t t$B jB JZ js ts Z sj 9s tBR Ys t sIB 7$t 8As B tB Ys{ 8Z{YB $ 8}B sj ZtBR R sP sAst s js $I s I JZ j YB8A tZt{s jj s ? s s RZ {s jBR s$ R V } $t{$}$BR I R$ jB j sR ? BtB8B A $ ? st${B 7$8Bt W b{B8A wdMnxTd ( D RBR t? s JZ j YB8A tB }BI ? s %Bjs tZt{s e s $8}BR$Aj {BtR Z$ $t t$BR 8 tBR } RsIBR JZ j s$ 7Z s9Bts8$ t B Zts - s}Bjs{$? Bt $t{B { s I js j k {ZsI sIBT{? ZA${s JZ $tT BIZ`$8BR t j {s}? ZjB d R {B8B R$ Z U j } RB I Zt s Ps{ B %BjsIB R } B}B {$Btsj s RZ %BjZ8 t 8$ t sR JZ js PZ 9s I RZR t s{$? Bt R } B}B {$Btsj s js RZ} h{$ Vj sZ8 t s j s8sK tB j } RB { { ? s 8Z{YB 8? sR ? s}$IB JZ js RZ} h{$ U "]ZstIB Zt s%$? Bt R s RZhT {$ t 8 t stI {B8B }s s {Bt t s Zt YB8A } Rs ? s I 8sR$sIB }s s JZ jB RBR t st RZR sjsR" _B{B I R}Z? R t d (n jBR tB s8 ${stBR ! %$jj k G$jAZ G $ Y {BtR Zk Bt j } $8 s%$? Bt Y${$ Bt sK t${BR R s Z8 t B <sk JZ sK tsI$ JZ W b{B8A tB R I RI$`B tZt{s I RZR sh 8s{$Bt R jj stIB $t{jZRB s sh 8s JZ tZt{s R {BtR Z$ ? s Zt s $jZ $B JZ PZ R {s}s9 I j %s s IBR } RBtsR k JZ }B st B g j $t% t B tB t? s t$t Zts Z $j$IsI } ? s{ ${s W b{B8A tB } tR? B JZ j YB8A I$R}BtI ? s A$ t } Bt B I 8s $sj R 8? sR j$ BR 8B B R I 8skB }B t{$s k JZ {BtR Z$ ? s s}s s BR s BI$t? s8${BR ej IB8$t$B I j s$ YsA? s I `sIB I R }s $8Bt$B I jsR s% R
© Los autores, 2001; © Edicions UPC, 2001.
@N
* $t Bt s e$tR $t
7Z} B? IB k RZ} %$R$? Bt NBR R t $IBR I j B? IB k I js %$R s I 7Z} 8st R ? st s8A$? t 8Zk I Rs BjjsIBR _B BIBR R RsA$IB JZ tZ R B RZ} Y? B $ t Zts {s}s{$IsI sZI$ $%s k %$RZsj 8Zk RZ} $B s js I Zt R YZ8stB _Z I B? {Bt% Rs{$Bt R j `stsR I$R $t Z$ BA` BR 8Zk sj `sIBR % t j $t $B I {$t BR B {s`sR { sIsR $t{jZRB 8$ $ {Bt RZR B`BR Zt }BI BRB skB {s}s9 I PZtI$ j 8? sR R$R t I jBR 8 sj R _ BI$ $BR R$t IZIs % IsIBR sj {B8? Zt I jBR 8B sj R sZtJZ tB s js {tBjB ? s JZ js YZ8st$IsI Ys I Rs BjjsIB zs8BR s stsj$9s {Bt Zt }B{B I I sjj R BR RZ} }BI R ej RBt$IB sj $ Zsj JZ js jZ9 B jsR BjsR I j 8s R Zts BtIs ]ZstIB R } Z As Zt sR Zt j? JZ$IB B Zt R? Bj$IB R } BIZ{ t BtIsR RBtB sR R I {$ } Z As{$Bt R JZ s%st9st s s%? R I j 8 I$B WB Ysk I R}js9s8$ t B t B I 8s $s ks JZ jsR 8Bj? {ZjsR I js RZR st{$s %$A st k {YB{st t R? } B tB 8BI$h{st RZ }BR${$? Bt 8 I$s sZtJZ Ysk stR}B I t ? s k I {st $IsI I 8B%$8$ t B et sZR t{$s I Zt 8 I$B 8s $sj stR8$RB RZj s $8}BR$Aj JZ j RBt$IB R } B}s Z sj B JZ t js h{{$? Bt RZ j Bj%$Is R s 8 tZIB 7sA 8BR JZ j R}s{$B $t }jst s $B $t R js R ? s } ? s{ ${s8 t %s{? B eR $8} tRsAj JZ }BIs8BR 8$ $ B {$A$ BtIsR RBtB sR s s%? R I ? j _B 8Z{YB JZ js h{{$? Bt R 8} K t t R R{ ts $B tB R Bk t jsR -}jBR$Bt R I jsR I %sR sIB sR As sjjsR t$ j Z$IB I jBR 8B B R I js ts% R t$ s8}B{B j 9Z8A$IB } BIZ{$IB }B j }sRB I 8 B $ BR k sR B$I R ]js B JZ {Bt R sR R ${{$Bt R jsR $8} R$Btst R As sjjsR R}s{$sj R {B8B jsR JZ $ t t jZ s t js Vj$st9s A jI k j y8} $B t Ns Z s I jsR sjs-$sR >7 s Gs R d H R$t Z$IBR t$ skBR JZ { Z9st I Zt jsIB s B B RZj s ? st 8Zk }B{B R} { s{Zjs R k s s{ $%sR =tB JZ$ } tRs JZ {ZstIB jBR Z$Bt$R sR {B8 t R $}B I B R I P? R${s j 8 t sj jB Ys{ t I PB 8s I j$A sIs }s s sj9s j R} { ? s{ZjB VZtJZ j 8? sR sARBjZ B I jBR R$j t{$BR I A $ t j %s{? B I j R}s{$B tB Ysk JZ jj s s jBR - 8BR }jst sIBR t j js B <$ Y zs{ZZ8 I ]Ys j R e s$t IBtI jBR sR BtsZ sR 8AZ $IBR t RZR s` R R}s{$sj R tB }Z I t B? RZR } B}$BR }sRBR "}B JZ tB Ysk s$ t j %s{? B" WB I A Bj%$Is R JZ j RBt$IB }Z I } B}s s R s8A$? t s s%? R I B BR 8 I$BR R? Bj$IBR B j? JZ$IBR k JZ t R {sRB I A ? s stR8$ $ R }B j } B}$B s` k jj s s RZR B? IBR s s%? R I j s$ $t $B JZ R}$ s j sR BtsZ s qs8A$? t jBR $8}s{ BR I jBR P s 8 t BR RZj st R I Zts -}jBR$? Bt {Bt js {s {sRs 8 ? sj${s I js ts% }BI ? st R R{Z{YsIBR t RZ $t $B }B j Y {YB I JZ js } Z As{$? Bt R stR8$ I j 8 sj sj s$ I js ts% et js {Zs s t s RBA jsR } $} {$sR I j YB8A I s{ B 7Z} 8st yz t AZR{s I js }s9 % 8BR sj RZ} Y? B }sR ? stIBR }B js NZts {B8B R$ sj {BRs R$t t { R$IsI I Zt s` I sR BtsZ s _s s RB R Zt R I ts Z sj 9s - s R s{ } ? 8BRjB sZtJZ s {BtI${$? Bt I JZ RZ AB{s tB 8$ s RBt$IB sj ZtB Ns % jB{$IsI I j RBt$IB I } tI I jsR } B}$ IsI R P? R${sR I j 8s $sj s s%? R I j JZ R } B}s s et {BtI${$Bt R tB 8sj R j RBt$IB R } B}s s t j s$ s n;; 8>R 8$ t sR JZ t j s Zs jB Ys{ {Zs B % { R 8? sR I } $Rs et t sj js % jB{$IsI I j RBt$IB R 8skB t jBR R? Bj$IBR JZ t jBR j? JZ$IBR k sR R eR B `ZR $h{s }B ` 8}jB j 8? BIB I s{ {s js B `s s js %? s I j t B sj RZ jB Z $j$9sIB }B jBR $tI$BR t jsR } j? {ZjsR I j B R B b R tR }s s I R{ZA $ js s} B-$8s{$? Bt I Zt t B I `$t R VI 8? sR j RBt$IB R s8B $ Zs 8 tBR }B $ s k RZ sj{st{ R 8skB
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
dxn
NBR st$8sj R $t{jZ$IB j YB8A Z $j$9st jsR BtIsR RBtB sR }s s $t {s8A$s $tPB 8s{$? Bt k }s s I { s k jB{sj$9s BA` BR NBR I$R}BR$ $%BR I { B R I j RBt$IB s{ ? Zst {Bt%$ $ tIB jsR %s $s{$Bt R I } R$? Bt I j s$ t %s $s{$Bt R I B sR 8s t$ ZI R 7 JZ$ JZ } BIZ9{st {Bt } {$R$? Bt jsR {s s{ ? R ${sR P? R${sR JZ I R{ $A t j RBt$IBU $t tR$IsI B t ? s }B Zt$IsI I $ 8}B k I RZ} h{$ k P {Z t{$s et j {sRB I j 8${ ? BPBtB RBt jsR %s $s{$Bt R I js {s}s{$IsI I Zt {BtI tRsIB {Zks 8 8A sts 4 -$Aj %$A s t R}Z R s s Zts BtIs RBtB s JZ$ t R B $ $tst Zts %s $s{$? Bt I js {B $ t j? { ${s JZ }Z I R 8 I$Is et j B? IB YZ8stB jsR %$A s{$Bt R RBtB sR {B $IsR }B j B? IB - tB }sRst sj ? 8}stB k R stR8$ t sj B? IB $t tB s s%? R I jBR YZ R {$jjBR eR BR s RZ % 9 stR8$ t jsR %$A s{$Bt R I j ? 8}stB s Zt 4Z$IB {Bt t$IB t jBR {stsj R I j B? IB $t tB js } $j$tPs JZ$ t sj 4 -$Bts j sA$JZ {B{j s R$ ZsIB t j {s s{Bj B {? B{j s -{$ s j R tR$Aj t %$B sZI$ $%B 3$tsj8 t jBR $8}ZjRBR t %$BRBR t sIBR R } B}s st YsR s j { A B JZ R t{s s I RZ $t } s{$? Bt NBR YZ R {$jjBR PZt{$Btst {B8B Zts } tRs Y$I ? sZj${s JZ s8}j$h{s ZtsR JZ$t{ % { R js PZ 9s ` {$Is }B jsR BtIsR RBtB sR RBA j ? 8}stB * RI j }Zt B I %$R s P? R${B j PZt{$Bts8$ t B 8 {? st${B I j B? IB R {BtB{ AsR st A$ t 7$t 8As B t js } { }{$? Bt I j RBt$IB $t %$ t t sI 8? sR I j } B{ Rs8$ t B s t$% j { A sj I js $tPB 8s{$? Bt sR} { BR RZA` $%BR JZ s? Zt tB R ? st B sj8 t -}j${sIBR ej B? IB YZ8stB {B8B j I jBR st$8sj R R Zts R Z{ Z s tB sAj eR R tR$Aj s Zt s8}j$B $t %sjB I RBt$IBR {Zks $t tR$IsI %s I RI js A$jjBt? R$8s I %s $B }B 8 B {ZsI sIB YsR s Zt %s $B }B 8 B {ZsI sIB p st }s I jBR RBt$IBR I tZ R B t B tB ts Z sj {s t I t B I R st B ej $t %sjB I sZI${$? Bt tB 8sj R RZA` $%B } B R Ysjjs j$8$ sIB }B j Z8A sj I sZI${$? Bt B $t tR$IsI 8? t$8s t { Rs $s }s s JZ Zt RBt$IB R s sZI$Aj k }B j Z8A sj I R tRs{$? Bt IBjB BRs V8ABR I } tI t I js P {Z t{$s 7$ js $t tR$IsI R 8$I t Zt$IsI R jB s ? 8${sR B I {$A j$BR j $t %sjB I sZI${$? Bt R R$ ? Zs }s s Zts P {Z t{$s I d!((( <9 t jBR ( k d1( I {$A j$BRU Zt $t{ 8 t B I d( I {$A j$BR R$ t$h{s Zt $t{ 8 t B t js $t tR$IsI I j RBt$IB I Zt Ps{ B d( * t B I R st B I sZI$A$j$IsI R Ysjjst jBR RBt$IBR } BIZ{$IBR }B jsR PZ t R YsA$ Zsj RU 8Z 8ZjjB n( I {$A j$BR {Bt% Rs{$? Bt tB 8sj E( I {$A j$BR {sjj {Bt ? sh{B ( I {$A j$BR $ B x I {$A j$BR I$R{B {s ( I {$A j$BR 8s $jjB t Z8? s ${B d(( I {$A j$BR ]B8B ks %$8BR t j {s}? ZjB d j B? IB YZ8stB }Z I I { s Zt st B I P {Z t{$sR t 1( k 1(!((( Y 9$BR R$ tIB RZ8s8 t R tR$Aj s P {Z t{$sR }B I As`B I jBR n!((( <9 _s s Zt t$% j I $t tR$IsI RBtB s IsIB -$R Zt $t %sjB I P {Z t{$sR JZ Zt B? IB tB 8sj }Z I } {$A$ 7Z} 8st Z $j$9s RZ RZ} B? IB }s s {s} s RBt$IBR I As`B t$% j I $t tR$IsI _Z I R{Z{Ys BR $t $8$IsI R stIB j }B ` 8}jB {Bt% Rs{$Bt R JZ $ t t jZ s t B s YsA$ s{$? Bt wgsI$? Bt I RZ s}s s B sZI$ $%B R ? s RZ} Y? B { {s D * A 8BR } tRs JZ j Z8A sj I sZI${$? }B I As`B I j YZ8stB }B jB JZ RZ Zt$% RB RBtB B R 8Z{YB 8? sR ${B WsIs }Z I t } $t{$}$B BA` s R s sj {s}s{$IsI 8$ t sR %sks s{B8}sK tsIs I js {B R}BtI$ t }BR$A$j$IsI I } B{ Rs BIsR jsR R K tsj R RBtB sR JZ R {$A t I PB 8s R$8Zj ? st s * tB R sR? js Is I Zts YB`s j {s8$ts s8}j$s{$? Bt I j st B I RBt$IBR sZI$Aj R w j Z$IB } BIZ{$IB }B js {s? I Zts YB 8$ s B Zts 8B s I }Bj%B JZ Bj} s {Bt s Zts % t stsD }BI ? s I `s I R Zts tB sAj {s}s{$IsI }s s {Bt% $ R t Zts $tRB}B sAj 8Bj R $s =ts -}j${s{$? Bt sj ts $%s I R RZ} }BI {BtR$R $ ? s t j {B8}B s8$ t B R j { $%B I j B? IB I 7Z} 8st eR I {$
© Los autores, 2001; © Edicions UPC, 2001.
dx;
* $t Bt s e$tR $t
j RZ} Y? B }BI ? s R j {{$Bts s %BjZt sI j Z8A sj I sZI${$? Bt k {s} s sR? j RBt$IB I R sIB sZtJZ R s I 8Zk As`s $t tR$IsI ej $t{Bt% t$ t RBA % tI ? s {ZstIB t Zts R$ Zs{$? Bt t JZ s}j${sR RZ RZ} B? IB t 8BIB I R tR$A$j$IsI 8? s-$8s }s s {s} s jBR R$ $jBRBR }sRBR I Zt 8sjY {YB js $tR }s sAj NB$R Nst }B ` 8}jB R B tZIsR { {s I ? j ! s tB sAj {s}s{$IsI I j B? IB YZ8stB R JZ } 8$ sj Bk t jB{sj$9s PZ t R RBtB sR k I$R{ t$ Zt RBt$IB R} {? h{B t 8 I$B I Zt t B tB }j B I Z$IB et jBR 8s8? P BR -$R Zts {B js{$? Bt t js Ps{$j$IsI I jB{sj$9s{$? Bt I jsR PZ t R I RBt$IB s I$% RsR P {Z t{$sR k jsR P {Z t{$sR JZ j st$8sj }Z I B? U R Ys BAR %sIB JZ R? BjB } {$A t Zt IB8$t$B I P {Z t{$sR t j JZ }Z I t jB{sj$9s I PB 8s h{$ t js PZ t RBtB s NBR 8s8? P BR JZ $ t t Zts R }s s{$? Bt stI t RZR B `sR }Z I t B? P {Z t{$sR 8? sR As`sR ej st B sZI$ $%B I j j Pst }B ` 8}jB R - $ tI s P {Z t{$sR 8? sR As`sR JZ j YB8A }B I As`B I jBR 1( <9 sZtJZ R? BjB sj{st9s jBR d(!((( <9 js 8$ sI JZ j YB8A NBR 8s8? P BR 8? sR } JZ K tBR t {s8A$B tB }Z I t } {$A$ A$ t jsR P {Z t{$sR As`sR sZtJZ -{ I t {Bt { { R j j? 8$ RZ} $B YZ8stB NBR } BR }B ` 8}jB RBt {s}s{ R I B? P {Z t{$sR RBtB sR I YsR s ;;!((( <9 8$ t sR JZ jsR s sR jj st YsR s jBR 1!((( <9 Ns {sZRs R$I t js js{$? Bt -$R t t j s8sK tB I js {sA 9s k js jBt $ ZI I BtIs {B R}BtI$ t I js BtIs RBtB s $t{$I t et Zts R{ ts I js } j? {Zjs 7Z} 8st yz t AZR{s I js }s9 j %$jjstB N - NZ YB 8} K tsIB t {BtB{ j R { B I js PZ 9s I j RZ} Y? B }s s sIZ K ts R I j 8ZtIB jjs8s s 7Z} 8st Z $j$9stIB Zt RBt$IB I P {Z t{$s RZ} $B s 1(!((( <9 N I${ JZ R js Z ?t${s { $s Z s JZ tB {s8$ts s {Zs B }s sR JZ }Z I B? RZ 8 tRs` 7$ tBR { 8BR R RZ} }BI Bt R {BtR {Z t D I j Y? B }BI 8BR sh 8s JZ R ? s t jB {$ B w}B jB 8 tBR JZ j Z$? ! s {BRs R {? B8B R jsR $t t$s }s s {BtR Z$ jB 7 ? Zt jB -}Z R B j s8sK tB I RZ {sA 9s I A ? s R $tP $B sj I Zts } RBts tB 8sj ! jB JZ R ? s JZ$%sj t js I$R st{$s t RZR B `sR 8 tB 57 $8s $tst2 WsIs I R B R BAR %s t 7Z} 8st {ZkBR sR BR tB I$h t s} {$sAj 8 t I jBR I Zt YB8A qs8A$? t t js } j? {Zjs _jst s } BY$A$IB >3B A$II t _jst d xEH Vj s$ s js Y$`s I j * B A$ZR YsA$ st I j }jst s Vj s$ Tyz Z $j$9s Zt R$jAs B JZ 8$ P {Z t{$sR $tsZI$Aj R }s s jBR YZ8stBR {B8B {js8B }s s {$ %BR k $ R eR B R s ? s t R$t Bt? s {Bt jB JZ Y 8BR I${YB eR BR st$8sj R RBt I R{ tI$ t R I jBR JZ js - $t Z$Is s9s sj$ t? ts I jBR , jj {s} Z ? B t Zts 8B s %$R$ s s js q$ s 1(( ((( sK tBR s ? sR _s { }jsZR$Aj s } $B $ JZ js %BjZ{$? Bt t Zt t B tB I$R $t B {B8B Vj s$ yz w s% IsI {B8}BR${$? Bt s 8BRP? ${sD Ysks $tIZ{$IB Zts {$ s I$P t{$s{$? Bt t jsR R} {$ R st$8sj R R} { B s RZR YB8? Bt$8sR R R sj B JZ tB R s} {$s t j hj8 Vt$8sj R {B8B jBR I jht R jsR 8s RB}sR k jBR 8Z {$? js BR Yst I Rs BjjsIB 8 {st$R8BR JZ Ys{ t ZRB I jsR } B}$ IsI R I jsR BtIsR RBtB sR }s s jB{sj$9s BA` BR e8$ t RBt$IBR I sj s P {Z t{$s Zj sRBt$IBR JZ sj R 4 `sIBR }B jBR BA` BR JZ jBR BI st j R } 8$ t I 8$ts RZ R$ Zs{$? Bt sI 8? sR I RZ PB 8s k ts Z sj 9s NBR 8Z {$? js BR }B ` 8}jB RBt } ? s{ ${s8 t {$ BR } B %Z jst %$ stIB jBR BAR ? s{ZjBR k {BtR$ Z t jB{sj$9s } JZ K tBR BtD 8 I$st js 8$R$? Bt I RBt$IBR I d1(!((( <9 *sIB JZ $tR { BR wjs AsR I RZ sj$8 t s{$? jsR BtIsR R? BjB }Z I t R } Z AsIsR }B BA` BR I I$8 tR$Bt R {B8}s sAj R B RZ} $B R s js jBt $ ZI I BtIs j s8sK tB 8? t$8B I jBR BA` BR JZ }Z I I { s R st$8sj R I j B I t I js jBt $ ZI I BtIs {B R}BtI$ t s R s P {Z t{$s R I {$ ZtBR n 88 ]$ s {jsR I I jht R jsR sPsj$tsR I { st $t%s $sAj 8 t t j s Zs }B Zt 8? BIB R$8$js BA` BR
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
@NN
]ZsI B n 1 *$P s{{$? Bt Ns {Z %s Z s I jsR BtIsR sj I IB I Zt BAR ? s{ZjB {B8B {BtR {Z t{$s I js $t P T t{$s I jsR I$P t R }s R I js 8$R8s BtIs R I tB8$ts I$P s{{$? Bt ej P t? B8 tB RZj s s} {$sAj {ZstIB js jBt $ ZI I BtIs R {B8}s sAj sj s8sK tB I j BAR ? s{ZjB B s Z` B RBA j JZ $t{$I Ns I$P s{{$? Bt I js jZ9 j$8$ s js t$ $I 9 I jsR $8? s t R PB 8sIsR }B jBR $tR Z8 t BR ?} ${BR k }B j B`B Ns jBt $ ZI I BtIs I js jZ9 %$R$Aj R I ( x 8$jjBt? B R$8sR I 8 B 8Z{YB 8? sR } JZ K ts JZ j s8sK tB I jBR BA` BR 8s{ BR{? B}${BR _B st B jBR BA` BR B I$ts $BR tB I$P s{ st s} {$sAj 8 t js jZ9 k ? R s R } B}s s t j? t s { s R$t I R%$s R et {s8A$B js jBt $ ZI I BtIs I j RBt$IB R I sj I IB I Zt 8 B {B8}s sAj s jsR I$8 tR$Bt R I jBR {Z }BR I tZ R B t B tB ej RBt$IB R I R%? s sj I IB I jBR BA` BR k R - $ tI t BIsR I$ {{$Bt R I ZtBR }B{BR 8$j? 8 BR I s8sK tB R$ ZsIBR s I$R st{$sR I %s $sR I { tsR I 8 BR I j st$8sj et js } j? {Zjs ej I? s I jBR ? hIBR >qY *sk BP Y q $^IR d EnH % R$? Bt $tP $B I js -{ j t tB% js YB8? Bt$8s I FBYt GktIYs8 >d xdH ZtsR }jst sR 8Z st R s {sZRs I js sI$s{$? Bt 8$ $Is IZ st Zts jjZ%$s I 8 B $ BR jB{sj$9st s RZR %? { $8sR }B j RBt$IB 7$ ? R sR } 8st { t 8ZIsR jsR }jst sR RBt $t{s}s{ R I I { s jsR ej } B s Bt$R s {BtR$ Z sj `s jsR Z $j$9stIB Zt {s8$? Bt JZ$}sIB {Bt Zt R$R 8s I sj s%B{ R Vj B R$8$js s {? B8B t }jst }s ? BI${B jBR YZ8stBR jB st % t{ s jBR $tJZ$ BR k A j${BRBR 8s {$stBR I s R V s{,R >d EH et R {sRB tB R st B j RBt$IB R$tB sj B 8? sR RZA` $%B jBR ZR BR 8ZR${sj R I jBR } JZ K tBR YB8A {$jjBR % I R $t%sRB R js {sZRs I RZ $ sIs =t I$R}BR$ $%B s $h{$sj JZ 8 Is j R$R 8s I {BjB{sj$9s{$? Bt Z $j$9sIB }B jBR I jht R R j RBts M I s8}j$B ZRB t js ts% s{$? Bt et js } j? {Zjs qY VAkRR >d M H j RZA8s $tB JZ } R$ Z s js { $s Z s sj$ t? ts Z $j$9s Zt RBts }s s R Z$ RZ }$R s ej I$R}BR$ $%B R 8}j s s8A$? t }s s RB s BAR ? s{ZjBR {B8B js I$R st{$s s jsR }s I R I Zt {sK t? Bt JZ j RZA8s $tB I A s s% Rs jB{sj$9s s B B RZA8s $tB YZtI$IB B j R t $IB I j 8B%$8$ t B I js { $s Z s ]B8B A$ t R 8Z R s t j hj8 tB }Z I Z $j$9s R }s s jB{sj$9s Zt 8$R$j } I$IB }B R Zt BA` B I 8sR$sIB } JZ K tB }s s 4 `s jsR BtIsR RBtB sR {Bt js RZh{$ t $t tR$IsI }s s JZ R st I { sIsR Ns RZ} %$R$? Bt R B B I jBR s $AZ BR {s s{ ? R ${BR I 7Z} 8st ej RZ} Y? B }Z I % s s%? R I jBR BA` BR BAR %s j {Bt t$IB I {$}$ t R { sIBR { ]? s8s sR I j %$R$? Bt k 8${ ? BPBtBR B{Zj BR RBt As s jsR t {B8}s s{$? Bt {Bt jB JZ R } RBts` R {s}s9 I Ys{ Ns jZ9 sj $ Zsj JZ j RBt$IB {B8}s jsR } B}$ IsI R P? R${sR t sj R JZ }BR t jsR BtIsR eR Zts %$A s{$? Bt I {s8}BR j? { ${BR k 8s t? ${BR JZ }Z I } B}s s R s s%? R I Zt 8 I$B 8s $sj k s I$P t{$s I sJZ j Ys{ jB s8A$? t t j %s{? B NsR BtIsR jZ8$tBRsR B B Zt 8$jj? Bt I % { R j { B8s t? ${sR R I R}js9st s Zts % jB{$IsI I n((!((( ,8>R t j %s{? s} B-$8sIs8 t 8? sR I } $Rs JZ jsR BtIsR RBtB sR t j s$ 7 {jsR$h{st }B RZR P {Z t{$sR B jBt $ ZI R I BtIs k sAs {st I RI jBR skBR s88s YsR s jsR BtIsR I sI$B }sRstIB }B jBR skBR jBR skBR Zj s%$Bj s js jZ9 %$R$Aj k jBR skBR $tP s B`BR M
V{ ? Bt$8B I 7BZtI Ws%$ s $Bt stI ist $t ts% s{$? Bt k jB{sj$9s{$? Bt }B RBt$IB
© Los autores, 2001; © Edicions UPC, 2001.
@N-
* $t Bt s e$tR $t
ej 8s I js %$R$? Bt R {B8}j `B ]ZstIB js jZ9 jj s s jBR B`BR } t s s s%? R I Zts sA Z s %s $sAj j $ $R k R tPB{s 8 I$st Zt R$R 8s I j t R {BtR $ Z$IB }B js {? B t s k j { $R sj$tB RBA js $ts Vjj? ZtsR {? jZjsR PB BR tR$Aj R wI tB8$tsIsR {BtBR k AsR Bt RD 8$ t $8}ZjRBR j? { ${BR {ZstIB RBt $jZ8$tsIsR V s%? R I j t %$B B ?} ${B R BR $8}ZjRBR RBt stR8$ $IBR sj { A B JZ$ t jsAB s Zts $t } s{$? Bt {B8B $8? s t R 8 I$st Zt } BT { RB {B8}j${sIB k s? Zt tB I 8sR$sIB A$ t {B8} tI$IB ej B`B YZ8stB {B8B j B? IB }BR } B}$ IsI R tB sAj R JZ Ys{ t I j 8$R8B Zts R Z{ Z s Z ?t${s ej {s8}B I %$R$? Bt {ZA dM(0 }Z I {s8A$s j tPBJZ }sRstIB ? s}$Is8 t I I$R st{$sR {B sR sj $tht$ B k RZ }BI I RBjZ{$? Bt R ? s } ? B-$8B sj j? 8$ $8}Z R B }B js I$P s{{$? BtU }Z I I$R $t Z$ BA` BR }Zt Zsj R A$ t $jZ8$tsIBR R }s sIBR n { t ? R$8sR I sIB ejjB R$ t$h{s JZ jBR I sjj R 8? sR htBR JZ }Z I t s} {$s R s R$8}j %$R s $ t t Zt s8sK tB I (, d 88 Ns $t tR$IsI 8? t$8s B Z8A sj }s s JZ Zt I R jjB jZ8$tBRB R s %$R$Aj I } tI I js jBt $ ZI I BtIs - tI$? tIBR t ${sR JZ R Ys IsIB t jjs8s jBR ; d( 8 k jBR d( 8 st B I jsR BtIsR j { B8s t? R} { B I js jZ9 %$R$Aj Ns R tR$A$j$IsI I j B`B R 8? s-$8s { {s I jBR x, x d( 8 wk sj B $tP $B }s s j B`B sIs} sIB s js BR{Z $IsI JZ R 8? sR R tR$Aj D JZ {B R}BtI s js jZ9 % I ej B`B YZ8stB tB R j Z ?t${B $}B I B`B sZtJZ 8Z{YBR st$8sj R RZ} $B R $ t t B`BR R t{$sj8 t $I? t ${BR s jBR tZ R BR 7Z s8sK tB tB }Z I R I 8sR$sIB } JZ K tB } B s8}B{B t { R$ s R 8skB NBR st$8sj R stI R tB t { R$ st B`BR IB sIBR I Zts RBjZ{$? Bt 8 `B JZ js I Zt R YZ8stB JZ R t{Z t s t j j? 8$ } 8$ $IB }B js I$P s{{$? Bt k }B st B tB RBt 8Z{YB 8? sR stI R =ts -{ }{$? Bt js {BtR $ Zk j {sjs8s $ st I j {Zsj -$R t ` 8}js R {Bt B`BR I 8? sR I ;( {8 I I$? s8 B B{Zjs et js {$ t{$s h{{$? Bt s}s { t { $s Z sR RB R? I B $ t - s R {Bt B`BR I stI R I$8 tR$Bt RU I RI j sj$ t? ts $t%sRB JZ s}s { t ej RZA8s $tB s ? B8${B >qY V B8${ 7ZA8s $t d E(H YsR s sj ZtBR I jBR {B8stIst R I js 4B s A jI I j hj8 ej B tB I j F I$ >i Z t BP Y F I$ d MnH I tBR }BR t B`BR 8skB R t RBR} {YBRB }s {$IB s Zt }Zj}B s stIsIB NBR st$8sj R } JZ K {B8}s s{$? Bt {Bt j s8sK tB I RZR {Z }BR JZ jBR I jBR R R YZ8stBR eR B R I A s JZ jsR {? jZjsR PB BR tR$Aj R I j B`B jBR {BtBR k AsR Bt R $ t t j 8$R8B s8sK tB t BIBR jBR B`BR I jBR st$8sj R JZ Z $j$9st R R$R 8s I %$R$? Bt 7$ 7Z} 8st 8}j s R 8$R8B R$R 8s RZj s I$P? {$j { JZ RZ %$R$? Bt }Z Is R 8 `B JZ js I Zt YZ8stB NBR $tR { BR tB }Z I t t ZtBR B`BR {B8B jBR tZ R BR R{sjsIBR s RZ s8sK tB }B JZ js I$P s{{$? Bt I js jZ9 IB8$ts ? s js PB 8s{$? Bt I jsR $8? s t R t js $ts <st I Rs BjjsIB Zt B`B {B8}Z R B PB 8sIB }B hA sR stR}s t R I tB8$tsIsR B8s $I$BR s Z}sIsR t PB 8s I 8 I$s RP s 7? BjB js jZ9 JZ $t{$I t {sIs hA s PB 8stIB Zt {$ B s ?t ZjB {Bt RZ ` { t sj }Z I s s% Rs js k R $8Zjs jBR t %$BR I js AsR eR s ?t ZjB I 8$ts j }BI RBjZ $%B I j B`B I j $tR { BU {Zst B 8 tB R s st B 8skB R ? s RZ RBjZ{$? Bt ej s8sK tB I R sR hA sR k }B st B j B`B I j $tR { B R j B ?} $8B et j hj8 Ns BR{s >qY 3jk d xMH js { $s Z s {Bt {Z }B YZ8stB k {sA 9s s stIsIs I 8BR{s % $8? s t R 8Zj $}j${sIsR ej }B}Zjs - s R JZ s}s { t js } j? {Zjs eq j - s R >e q qY e- sT q R $sj d M1H R ? s IB sIB I Zt }s I tB 8 R B`BR ej I$R K tB I { $s Z sR {Bt stI R B`BR R Zt {Z RB YsA$ Zsj RBA BIB t jBR I$AZ`BR st$8sIBR {ZstIB R } tI I R} s R t $8$ t BR sj R {B8B js tZ s t j R} { sIB
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
dx
I Zt 8$R8B BA` B {B8B R$ {sIs }s I j B`B I $tR { B s $ st sIB } BIZ` R Zts $8s t {B8}j s ej }B t{$sj %$RZsj I 7Z} 8st }s { % t$ 8? sR A$ t }B j jsIB I js R tR$A$j$IsI s B sR jBt $ ZI R I BtIs R$ ZsIsR 8? sR sjj? s I j st B I js jZ9 %$R$Aj ]B8B Y 8BR I${YB j B`B YZ8stB R R tR$Aj s Zts R {Ys AstIs I j R} { B j { B8s t? ${B 5_BI ? s PB 9s R j B`B s R R tR$Aj s B sR jBt $ ZI R I BtIs2 Vj ZtsR } RBtsR B} sIsR I {s s s sR w j { $R sj$tB R %Z j% B}s{B k R j$8$tsIB JZ$ ? Z ${s8 t D RBt R tR$Aj R s js sI$s{$? Bt Zj s%$Bj s JZ Zt B`B tB 8sj tB }Z I {s} s et js } j? {Zjs ej YB8A {Bt skBR t jBR B`BR >qY st G$ Y Tisk ek R d EnH j IB{ B s%$ $t% R $ s js }BR$A$j$IsI I R tR$A$j$9s j B`B s B sR jBt $ ZI R I BtIsU "eR B R jZ9 BtIsR I t ? s JZ -{$ st j B`B k j t %$B B ?} ${B stR8$ R s t ? s sj { A B k {Bt j { A B % 8BR _ B Ysk B sR PB 8sR I t ? s I I$P t jBt $ ZI I BtIs _BI 8BR AZR{s Zts PB 8s I R tR$A$j$9s j B`B s B sR jBt $ ZI R I BtIs $t{jZk tIB jBR skBR s88s k jBR %$ t BR {? BR8${BR" * R}Z? R I tRsks Zt } }s sIB JZ? 8${B {BtR$ B 8$R8B 8}$ 9s s % s s%? R I jBR `$IBR k I jsR }Z sR ej $tZR$ sIB Zt$% RB %$RZsj JZ R sA st RZR R tR$Aj R B`BR RBA }sRs js {s}s{$IsI I sR$8$js{$? Bt I Zts 8 t YZ8sts O A$ t tB I R% js 8BR j htsj Vj B R$8$js s jB JZ RZ{ I t js tB% js qY =tRj }$t ek >d ;H I *s%$I p ]B8} Bt IBtI R ts st jBR } BAj 8sR -$R t{$sj R I Zt YB8A {Bt {? s8s sR I j %$R$? Bt $8}jst sIsR t RZR B`BR et j B B - 8B I j }s s? RB %$RZsj *s I %$j >d E;H B *st * P tRB {B8B R j {BtB{? s }B sJZ? R j Z ?t${B RZ} Y? B $t%$I t I j Zt$% RB { sIB }B js Ps{ B ? s s % j 7Z $I t $IsI sj R js I Zt sAB sIB s Z IB{, s JZ$ t s s? 9 I j s{{$I t JZ j I `? B {$ B R j s ZI$9st jBR B BR R t $IBR k I Rs Bjjs Zt sIs R} {$sj p s{$sR s jjB tB R? BjB tB R Ysjjs t Zt R sIB I $tI P tR$? Bt R$tB JZ RZR R} {$sj R YsA$j$IsI R j } 8$ t tP t s R s jBR Ps{$t BRBR {B8B Ys ? s {ZsjJZ$ RZ} Y? B R$t 8$tZR%sj? sR P? R${sR _B {$ B j sAs`B tB j Psj s s R } RBts` U jBR 8sj%sIBR JZ I $ t As`B RZ $I t $IsI I RZ} Y? B R {Bt%$ t t RZ I P tI$IBR {ZstIB sIB} s RZ }s} j I sAB sIB z t s`sR I js IBAj } RBtsj$IsI q tI 8BR s { JZ tZ R BR R t $IBR tBR Ist Zts $8s t {B8}j s I jB JZ tBR BI s WsIs 8? sR j `BR I js sj$IsI ]B8B V YZ ] ]js , R K tsjsU "eR s8BR RB IBR {B8B Zts s}$s k {$ BR {B8B Zt }B9B s jBR {BjB R t Zt 8ZtIB I $8} R$Bt R 8? sR sjj? s I j sj{st{ I tZ R BR R t $IBR ej 8ZtIB I j } B R Zt 8ZtIB I BjPs B j 8ZtIB I Zt I jP? t R Zts R$tPBt? s I tB sR Zj sR? Bt${sR JZ }s s ? j $ t t j 8$R8B R$ t$h{sIB JZ js %$R s _s s js sA `s t Zt I? s tZAjsIB js I$PZRs jZ9 RBjs jj %s Zt R$ tB $tI${sIB I js I$ {{$? Bt JZ R ? s }B t{$8s I BIBR jBR }BI R YZ8stBR I BAR %s{$? Bt sZtJZ }Z I R I { sIB t j }jstB I %$A s{$? Bt I jsR BtIsR jZ8$tBRsR >}Bjs $9s{$? BtH" Ns BAR %s{$? Bt t B sR jBt $ ZI R I BtIs tBR } 8$ s{{ I s Zts $tPB 8s{$? Bt JZ } 8st { % IsIs s tZ R BR R t $IBR et sR BtB8? s jsR BAR %s{$Bt R sI$B j R{? B}${sR k t jsR AstIsR $tP s B`s k s88s I j R} { B j { B8s t? ${B Yst sA$ B Zts }stB s8s $tRBR} {YsIB
© Los autores, 2001; © Edicions UPC, 2001.
dxM
* $t Bt s e$tR $t
! BR B`BR B BR 8ZtIBR et js h{{$? Bt j s Z8 t B I j {Bt s{ B {Bt R} {$ R - s R R Ys } 8$ $IB R} {Zjs t B tB s }BR$Aj R 8 {st$R8BR I sIs} s{$? Bt s B BR 8 I$BR ej B? IB js %B9 k js %$R$? Bt tB RBt t { Rs $s8 t jBR 8 {st$R8BR 8? sR $I? Bt BR t I 8$tsIBR jZ s R et j {s}? ZjB ; % 8BR ` 8}jBR I R tR$A$j$9s{$? Bt I R} {$ R st$8sj R s {s8}BR j? { ${BR k 8s t? ${BR WB R {sRZsj }B ` 8}jB JZ j B`B YZ8stB k I js 8skB ? s I jBR st$8sj R } R t Zts R tR$A$j$IsI 8? s-$8s s js jZ9 %$R$Aj U j 7Bj 8$ js 8skB }s I RZ t ? s t R st B et R$R 8sR }jst s $BR I$P t R {Bt R jjsR t B BR R sI$BR %BjZ $%BR js R tR$A$j$9s{$? Bt I j B`B s js AstIs $tP s B`s B Zj s%$Bj s }BI ? s R 8? sR s} B}$sIs VR? j sj$ t? ts I js } j? {Zjs * } IsIB >_ Is B d M H sI 8? sR I }BR Zt {s8Z4s` I $t%$R$A$j$IsI I$R}Bt I I { B R I $tP s B`BR 7 tP t s sj Z ?j $8B RZ} %$%$ t I js Zt$IsI I RBjIsIBR JZ Ys st$JZ$jsIB ej RBjIsIB {B8}j s8 t I Rs 8sIB {BtR$ Z I PB 8s s{{$I t sj R{sAZjj$ R I j {s8}B I %$R$? Bt I R $8}js{sAj t 8$ B s AsR I 8AsIZ ts R I As B BIB j {Z }B jB JZ Ys{ 8? sR I$P? {$j RZ I {{$? Bt et js R {Z js * } IsIB 1 >_ Is B 1 d (H jBR sj$ t? tsR }Z I t {s8A$s s %BjZt sI RZ } { }{$? Bt I js sj$IsIU Zt I$R}BR$ $%B j R } 8$ {s} s js sI$s{$? Bt I B sR 9BtsR I j R} { B *$R8$tZ$ js 8} s Z s {B }B sj wsj B tB 8Zk {B8 tIsAj }s s B st$R8BR %$%BRD B Z $j$9s Zt R{ZIB ? 8${B JZ s}st sjj js sI$s{$? Bt $tP s B`s RBt sj ZtsR RBjZ{$Bt R }s s RJZ$%s j s{BRB I R BR {s9sIB R - s R R qBIBR jBR {Z }BR 8$ t BtIsR j { B8s t? ${sR t BIsR jsR jBt $ ZI R I BtIs Ns {st $IsI I t ? s sI$sIs t {sIs jBt $ ZI I BtIs I } tI I js 8} s Z s I j {Z }B ]ZstIB ? R s sZ8 t s js jBt $ ZI I BtIs s js {Zsj $ t jZ s js 8? s-$8s 8$R$? Bt R I R}js9s Ys{$s %sjB R 8? sR } JZ K tBR eR Y {YB %$ t -} RsIB }B js j k I G$ t Ns 8} s Z s I js RZ} h{$ RBjs ZtBR x! (( 0 ] I 8$ts js jBt $ ZI I BtIs s js {Zsj jj s s js q$ s js 8skB }s I js sI$s{$? Bt RBjs eR s jBt $ ZI I BtIs {B R}BtI s js }s %$R$Aj I j R} { B j { B8s t? ${B et j {sRB I j YB8A k I jBR st$8sj R {Zks 8} s Z s {B }B sj Bt 8? s-$8s {B R}BtI s js 9Bts R 8Zk $tP $B wZtBR nE, x 0 ] }s s jBR R R YZ8stBRD js 8$R$? $tP s B`s Ns R }$ t I {sR{sA j JZ }BR Zt R$R 8s I { B I $tP s B`BR s} B% {Ys R Y {YB }s s {s9s s RZR } RsR eR t R s AstIs I R} { B IBtI jBR %$ Bt R t R I t ? s }Z s I R{ $ BR t j js B I e ${ 3 iZRR jj s s R$t$ R s >7$t$R s $ d ;nH sARB A t k sI$st t ? s k RZj st }B st B $t%$R$Aj R s jBR B`BR I jBR YZ8stBR e-$R t I$R}BR$ $%BR JZ } 8$ t js %$R$? Bt tB{ Z ts {B8B jBR I { B R I $tP s B`BR k 8? sJZ$tsR }s s j I$s t? BR ${B 8? I${B {B8B jsR I skBR t{s sIsR I % js j $t $B I j {Z }B YZ8stB s AsR I } B}B {$Bts jsR Z $ts $sR sI$B sP? sR VI 8? sR I jsR {s}s{$IsI R I j B`B YZ8stB js RZ} %$R$? Bt I j YB8A I s{ B $t{B }B s js R tR$A$j$IsI st B s jBR skBR {B8B s jBR skBR $tP s B`BR I sj R I$R}BR$ $%BR =t RZ} B`B %s8BR VZtJZ {B8B ks {B8 t ? sAs8BR t j {sRB I j B? IB RZj s t { Rs $B JZ j RZ} Y? B }Z Is R$t Bt$9s s %BjZt sI j st B I jBt $ ZI R I BtIsR I jsR BtIsR j { B8s t? ${sR JZ I R s $t { } s 7$ t jBR RZ} Y? B R stsj$9sIBR }BI 8BR t{Bt s sj ZtBR ? 8$IBR RPZ 9BR }B 8st t Zts {$ s {BY t{$s t js P? R${s JZ {BtB{ 8BR k js JZ }s { $ t js h{{$? Bt -$R t B BR 8Z{YBR {sRBR t jBR JZ R Ys IsIB $ tIs RZ j s sj BIB %sj zs8BR s {Z} s s
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
@N
3$ n d( Ns RZ} %$R$? Bt }Z I s{s s s 7Z} 8st } BAj 8sR $tRBR} {YsIBR sj ZtBR I R BR R R {ZkBR %$RBR I sj$IsI {s t 8? sR sjj? s I {ZsjJZ$ R} {Zjs{$? Bt et t jj %sIsR sj {$t t jBR {B8}Bt t R I NBR ]Zs B 3st ? sR ${BR w{ZksR s% t Z sR Yst R$IB s8A$? qY 3st sR ${ 3BZ >d nHD t 8BR sj YB8A j? sR ${B js 8Z` $t%$R$Aj js st B {Ys YZ8sts k j YB8A I }$ I s {ZksR YsA$j$IsI R RBt P? s{$j R I $8s $ts VIJZ$ t R BR }BI R RBA YZ8stBR sj % R sP { sIs js ts% R}s{$sj t JZ %$s`sAst }B jBR {$t Z Bt R I sI$s{$? Bt I zst Vjj t R BR R? sj R JZ BI st js q$ s *$R{Zj}s8BR R s } $ts `ZR $h{s{$? Bt I j B $ t I R {Zs B }Z R B JZ R sR 9BtsR I {Bthts8$ t B }B j {s8}B 8s t? ${B R I }s ? {ZjsR {B8B j { Bt R k } B Bt R YsA? st R$IB I R{ZA$ sR R? BjB R sK tBR st R I JZ R 8 t s st t j {? B8${ ! BR {Z $BRBR RZ} Y? B R RBtU eR js }js sIs >7$j% 7Z P H Zt tB } s{ ${st I RZ P {BtI tsIB s } s{ ${s R I }B g}B js s 8? BRP s R N$t ts % I >p t Nst t d ;(H Zt $tI$%$IZB JZ }BR Zt 8$R $BRB st$jjB PsA ${sIB {Bt Zt 8 sj I B $ t - s R JZ j {Bth }BI R sj R {B8B %Bjs s s% Rs jsR }s I R k R $t8Zt s jsR AsjsR wgk jB JZ Ys s Psj s %s8BR D k eR} { B >qY 7} { d ;(H Zt }Bj${? s % R $IB I % I {Bt s8}j$BR }BI R JZ RZ R sIB Pst sR8sj }s { `ZR $h{s w{js B gR$ %$ t I j B B 8ZtIB D NBR Ysk }s s BIBR jBR ZR BR
n ;
WZ %BR YB8A R }s s j 8sK tsts
"VYB s 8$R $ sR I {s t st }B{sR k 8$t$8$9sIsR k jBR : 8}js9s8$ t BR: I sj s{$? Bt I 8 sj {BtR $ Z? st js 8skB }s I 8$ R}j tIB {B }B sj" * jBR 8}sR R AZ{sj R YsR s jBR 8s {s}sRBR B jsR } ? B R$R I {sI s jBR $8}jst R 8? I${BR tBR RZj st Ps8$j$s R k Yst R$IB - s}BjsIBR {Bt 8skB B 8 tB PB Zts `Zt B s RZR {BtR {Z t{$sR t js h{{$? Bt =t $8}jst }B sJZ? Zts } ? B R$R 8 {? st${s }B sjj? s k g9sR ks t 8BR Zt Y? A $IB YB8A T8? sJZ$ts Zt B T Bt st$R8B {$A t? ${B 8? sR {BtB{$IB {B8B {kAB @ =ts I jsR } $8 sR BA sR I {$ t{$s h{{$? @
]Bt s{{$? Bt I j $t j? R {kA t ${ B st$R8
© Los autores, 2001; © Edicions UPC, 2001.
@-
* $t Bt s e$tR $t
IBtI s}s { Zts P t{$s -}j? {$ s s R ? 8$tB R js tB% js I s $t ]s$I$t ]kAB >d 1H sZtJZ js 8? s ${s YsA? s R$IB }jst sIs ks t B sR tB% jsR {B8B js -{ }{$Btsj N$8AB >d x1H I ts I GBjP B js Rs ? ${s BI st >d dH I *s%$I i Zt{Y {Bt Zts I {ZksR P sR R $t${$? sAs8BR R s}s sIB et js } $8 s jBR RPZ 9BR I Zts YZ8st$IsI I$ 98sIs }B js { s Z s 8ZtI$sj }B - $ }s RZ s R$%$IsI I R 8AB{st t js s8}Z s{$? Bt %BjZt s $s I jsR - 8$IsI R k js {Bt% R$? Bt I jBR YB8A R t B st$R8BR {$A t? ${BR et js R ZtIs jBR 8$ 8A BR } B ? R${BR tB R? BjB RBt 8? sR {s}s{ R R$tB JZ {BtR $ Zk t s 8sR 8Z{YB 8 `B R ! sR %$R$Bt R I Zt PZ Z B IBtI jBR $8}jst R k jsR } ? B R$R A$B8 {? st${sR R ? st s js B I t I j I? s jsR t{Bt s8BR t jBR {? B8${R `s}Bt R R B 8st s et qY pYBR $t Y 7Y jj I sRs8Zt 7Y$ Bb R s s Zts YZ8st$IsI I htsj R I j R$ jB y {BtR $ Z$Is t RZ 8skB ? s }B {kT AB R eR BR {BtR %st RZ R$R 8s t %$BRB {$ {Zjs B $B k I$ R $%B } B }BR t - 8$IsI R k 8? ZR{ZjBR s $h{$sj R k Zts tZ %s {sA 9s IB sIs I 8? Zj $}j R R tRB R {Bt { sIBR s jBR t %$BR B} ${BR k sZI$ $%BR 5eR ? ? st R BR R R 8 I$B YZ8stBR 8 I$B 8? sJZ$tsR t I$R}BR${$? Bt I 8Zjs I RI Zts } R} { $%s 8? sR { ? Aj jsR } B 9sR I jBR RZ} Y? B R I {s t k YZ RB2 7 % VZR $t Zt st $ ZB sR BtsZ s I jsR PZ 9sR s? sR tB s8 ${stsR RZP Zt s% s{{$T I t 8$ t sR }$jB sAs Zt s%$? Bt -} $8 t sj Ns 8BI ts {tBjB ? s } 8$ JZ Zts }s I RZ I R B9sIB {Z }B R s {BtR Z$Is {Bt j 8 t BR s $h{$sj R * R s PB 8s sIJZ$ IBR tZ %sR }$ tsR Zt A s9B k Zt B`B $tI$R $t Z$Aj R I jBR B $ $tsj R } B RZ} $B R t {Zst B s } R s{$Bt R ej {BR I js B} s{$? Bt R $R 8$jjBt R I I? Bjs R ej RZj sIB Zt YB8A A$? Bt${B wR ? Zt j ? 8$tB }B}Zjs $9sIB }B js R $ j %$R$%sD Zt R {s}s9 I sj$9s s sR RBA T YZ8stsR _Z I {B s % jB{$IsI R $t{ ? Aj R k P { Zs s{{$Bt R JZ JZ$ t Zts tB 8 PZ 9s P? R${s eR tZ %B 7Z} 8st 8BI tB {BtB{$IB {B8B ej YB8A I R $R 8$jjBt R I sR }s s {B Is j js I ZIs {Bt s? Is {Bt j I? Bjs R >7$- $jj$Bt *Bjjs st d nT MH w5JZ$9? R sIB2D t s ? s s sAs`s sj R %${$B I js ]yV {B8B s t R} {$sj 7Z {Bt s}s $Is P T 8 t$ts R Fs8$ 7B88 R Ns 8Z` A$? Bt${s > $Bt${ GB8st d ET MH ]B8B RZ } I { RB }BR Zt {Z }B {BtR Z$IB sR Zt R % B s{{$I t U IBR }$ tsR tZ %sR Zt A s9B Zt B`B k Zts B `s {Bt js JZ }B ` 8}jB }Z I I { s {ZsjJZ$ Z$IB YsR s d, x ,8 I I$R st{$s w5 {Z Ist jB JZ ks {B8 t s8BR sj R} { B I j RZ} B? IB I 7Z} 8st2D q sAs`s s8A$? t }s s Zts { t sj I $t j$ t{$s I j BA$ tB gVY js s{B8}sK ts Zt h j } B s8A$? t A$? Bt${B jjs8sIB s- Z{YsR I jsR Ys9sK tsR JZ st B j {B Bt j VZR $t {B8B Fs8$ 7B88 R sj$9st RZj st $8}BR$Aj R I RI j }Zt B I %$R s P? R${B Vj $ Zsj JZ t j {sRB I 7}$I 8st 7Z} 8st k {B8}sK t? s RZR RZ} }BI R R % t R $t $IBR }B jsR j$8$ s{$Bt R JZ $8}Bt t jsR j k R P? R${sR Vtsj${ 8BR sj ZtsR I RsR $t{ ? Aj R } B 9sR et ZtB I jBR }$RBI$BR I js R $ j YB8A A$? Bt${B %$s`s t j sR$ t B I j {B}$jB B I Zt sZ B8? B%$j JZ Z Is }B Zt s8B { B {ZjB R Ysjjs R$t P tBR k R$t IZIs jB Zt I Zts {s s s Zts % jB{$IsI I ( ,8>Y ej % Y? $tR st VZR $t sA js }Z s k P ts s{$sR s js P ${{$? Bt JZ } B}B {$Bts j {Bt s{ B I RZ {sj9sIB {Bt j sRPsj B ej sZ B R I $ t t ZtBR d( R ZtIBR Ns I$R st{$s {B $Is YsR s }s s R {B8}j s8 t }Z I I 8$ts R Z $j$9stIB js R ZtIs j k I W b Bt RsA$ tIB JZ js Z ?t${s PZ 9s JZ s{ ? Zs R js I B9s8$ t B eR s I$R st{$s RZj s R I d(( 8 wRZ}Z R s Zts 8sRs I j {Bt`Zt B % Y? {ZjBTVZR $t I d!((( , D _BI 8BR RZ}Bt JZ jsR YsA$j$IsI R A$? Bt${sR I j Y? B j } 8$ t I t j % Y? {ZjB t js PB 8s I R{ $ s 7$t 8As B js PZ 9s
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
@-@
I B9s8$ t B tB R s}j${s RBA j { t B I 8sRsR I j BA` B R$tB t RZ }s - ts et {BtR {Z t{$s j YB8A A$? Bt${B tB }BI ? s %$ s Zt 8B%$8$ t B I B s{$? Bt t R t $IB YB s $B JZ s sR s ? s sj % Y? {ZjB PZ s I js {s s t {Bt s I jB JZ RZ{ I t js R{ ts j %$R$%s O RB R$ {BtR$ Z 8st t R sP sIB k RBj$Is $B sj % Y? {ZjB * jB {Bt s $B j P { B }sjst{s jB s B`s ? s PZ s I j 8$R8B ej YB8A A$? Bt${B R s8A$? t {s}s9 I jB s s{ j s{$Bt R $t{ ? Aj R {ZstIB Zts R$ Zs{$? Bt I 8 t{$s sR? jB JZ$ et B B }$RBI$B s{ j s I RI j }BRB YsR s sj{st9s jBR d(( ,8>Y t Zt $t %sjB I $ 8}B I 1 R {Bt BA` B I sI jst s sj % Y? {ZjB {BtIZ{$IB }B Zt s t - st` B eR B RZ}Bt Zts s{ j s{$? Bt I d, ; %sjB IBR % { R RZ} $B sj 8? s-$8B {B8 tIsIB t % Y? {ZjBR {B8B sZ B8? B%$j R sZtJZ t } $t{$}$B Bj sAj }B Zt R YZ8stB w]s}? ZjB 1D et 8Z{YBR }$RBI$BR }Z I % R s VZR $t Rsj stIB I RI j RZ jB Ys{$s jB sj B I Zt I$h{$B B %${ % Rs Ns s{ j s{$? Bt I j %s{$? Bt t { Rs $s }s s sj$9s Zt Rsj B I 1( 8 w I$h{$B I ZtsR x }jst sRD R ? Zt j 8BI jB I j Rsj B JZ {B8 t s8BR R I ;( =ts s{ j s{$? Bt JZ RZR }$ tsR 8 {? st${sR }Z I t R {s}s{ R I {B8Zt${s j } B JZ j R B I RZ {Z }B YZ8stB tB R ? s {s}s9 I RB}B s Ns PZ 9s ` {$Is }B R sR }$ tsR 8 {? st${sR I 8$tsIs {B8B j } BIZ{ B I js s{ j s{$? Bt }B jBR M( , I js 8sRs I VZR $t R I ZtBR nd3((( W JZ$%sj t s js PZ 9s t { Rs $s }s s j %st s Zts 8sRs I n3d(( , qs8A$? t }Z I % R sj YB8A I R $R 8$jjBt R I I? Bjs R s B`stIB } RsIBR BA` BR RBA RZR t 8$ BR et Zts B{sR$? Bt jst9s Zt tB 8 } I ZR{B I Zts Bt jsIs I } RB 7$ j BA` B sAstIBts RZR 8stBR s Zts % jB{$IsI 8BI sIs I nE ,8bY j } $t{$}$B I {BtR %s{$? Bt I js {st $IsI I 8B%$8$ t B -$ JZ tZ R B YB8A Rsj s I$R}s sIB t R t $IB B}Z R B s Zts st I$R}Z R BR s {BtR t $ et B BR % jB{$IsI gI ;x( ,8bY Vj B JZ RZR R Z$IB R tB R ? }$RBI$BR R BR R R A$? Bt${BR ` {Z st s{{$Bt R JZ JZ$ t Zts st PZ 9s P? R${sU IBAjst jBR As B R I Y$ B I Zts `s B B8} t Zts {sI ts h`sIs }B Zt - 8B s js }s I _s s jjBR tB }s { t -$R $ jsR As sR P? R${sR qBIsR R sR R sR RBt R$t 8As B $ts{ } sAj R _B ` 8}jB R$ j YZ8stB A$? Bt${B ` { Zts PZ 9s RBA jBR As B R ? R BR t %$ ZI I js j k I s{{$? Bt k s{{$? Bt P { Zs ? st Zts PZ 9s {? } B{s RBA ? j I $ Zsj 8s t$ ZI k I R t $IB B}Z R B _B st B I A ? s R} s R Zt 8B%$8$ t B t B I j Y? B t j R t $IB {Bt s $B sj I js PZ 9s JZ I Rs Bjjs WB BAR st jsR j$8$ s{$Bt R PZtIs8 t sj R I R $}B I R R {$A t? ${BR } B{ I t I RZ 8$R8s ts Z sj 9s Y? A $Is 7ZR }BI BRBR 8$ 8A BR Z B ? stBR s $h{$sj R }Z I t PZt{$Bts 8 `B k R 8? sR {s}s{ R JZ sJZ jjBR s jBR JZ Yst RZ}jst sIB } B I A t R } R t JZ Yst R$IB $8}jst sIBR t Zt {Z }B YZ8stB eR I {$ {B -$R t {Bt YZ RBR 8? ZR{ZjBR tIBt R k %? R{ sR NsR $tI R Z{ $Aj R }$ tsR I j YB8A A$? Bt${B }Z I t RB}B s } P { s8 t Zts {s? Is I RI Zts j %sIs sj Z s } B s AZ t R Z B js {sI s B js {BjZ8ts % A sj s js JZ ? R sR R Ysjjst Zt$IsR R st $t{s}s{ R I Ys{ jB _B B B jsIB 5AsR s j PZt{$Bts8$ t B I Zt {B s9? Bt k I ZtBR }Zj8Bt R YZ8stBR }s s s}B s js t ? s JZ R t { R$ s }s s 8B% RsR }$ tsR PB 8$IsAj R s js % jB{$IsI 8BR sIs t js R $ 2 et js %$Bj t s } j? {Zjs 7BjIsIB Zt$% Rsj >=t$% Rsj 7BjI$ d 1H R ts s j RZj sIB I Zt } Bk { B {$ t ? h{BT8$j$ s JZ } tI { s Zt {Z }B I ? j$ I RZ} RBjIsIBR _s s jjB
© Los autores, 2001; © Edicions UPC, 2001.
@-
* $t Bt s e$tR $t
3$ n dd w8TT )ID 7 % VZR $t Zt YB8A wA$? Bt${BD JZ {BR ? B R $R 8$jjBt R I I? Bjs R Z $j$9stIB RZ RZ} PZ 9s w8)I<*D Ns 8Z` A$? Bt${s B {? B8B }sRs R j I? s s B t$jjstIB jsR } ? B R$R 8 {? st${sR
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
dEn
R %$% t w D RBjIsIBR 8Z BR t js Z s I z$ ts8 JZ Yst R$IB 8st t$IBR t R sIB { $B ? t${B k s jBR JZ R I R}B`s I %BjZt sI k I R t $8$ t BR JZ }Z Ist t B } { RZR PZ Z sR s{{$Bt R WB R s s I $8}jst s } ? B R$R 8 {? st${sR R$tB I I Rs Bjjs 8 I$st Y$}B ? ${BR R $8Zjst R k I B sR k jsR sj B 8? sR % BR? 8$j R ? {t${sR I js $t t$ ? s t? ${s jsR }B t{$sj$IsI R P? R${sR I j {Z }B YZ8stB NBR R R { sIBR RBt jBR
% Rsj RD RZ} YB8A R JZ s{ ? Zst {B8B RBjIsIBR $I sj RU tB }$ tRst R? BjB BA I { t k s{ ? Zst ytR tR$Aj R sj IBjB k s jBR I R B9BR {B }B sj R JZ RZP t IZ st jsR s $ R sIsR 8$R$Bt R w T 8 tIsIBR
=t$7BjI wRBjIsIBR Zt$T
s{{$? Bt Ns As sjjs {s8}sj t IBR I R BR RZ} RBjIsIBR s JZ$ t R js {Z} s{$? Bt I RZ $I t $IsI Ys{ s4B s RZ st $ Zs t 8$R sI RZj s R} { s{Zjs } B t B R P? R${BR I AZj B 7sj BR }ZK t s9BR k PB { ` BR RBt $t% BR? 8$j R O }B R$ R B PZ s }B{B j R BR $tI$%$IZBR {BtR$R t JZ R ? st {BthtsIBR t {Z }BR YZ8stBRU RZR { ? st BR s s%$ Rst }s sA $RsR RZR }ZK tBR I R B9st jB JZ R }Bt }B I jst gR$t 8skB R R {Z jsR }BR $B R et B s } j? {Zjs I {s8$Bt BR s}s { Zt `? {$ B I " Z BR A$B8 {? st${BR 8st$}ZjsIBR t? ${s8 t " =t$IsI R I R BR R R RBt stR}B sIsR B{Zj sR }s s {BtJZ$R s js q$ s 7 s{ $%st }B Bj sIsRU t j {sRB I JZ Zts Zt$IsI R s I R Z$Is B sR IBR t st t s{{$? Bt jZ B {Zs B B{YB =ts $t%sR$? Bt t s}s $ t{$s I$P? {$j I I t
$t R$ Z t Zt {s8$? BtTjsAB s B $BTYBR}$ sjD RZ RZ} PZ 9s }s { `ZR $h{s {ZsjJZ$
} JZ K tB I P { B I
7}s{ q Z{, R >d EH Zts }s BI$s t {js% I {$ t{$s h{{$? Bt I jsR } j? {ZjsR
V 8sIZ sR -B RJZ j BR k B sR j$tI 9sR 7$ {Z $8BR I tZ %B s jBR RZ} Y? B R {j? sR${BR Ysjjs 8BR B s 8st s I {Bt`Zt s }s R 8 {? st${sR {Bt {Z }BR YZ8stBR t ej Z tB I Y {YB tB R sj B I 8sR$sIB B $ $tsj NsR s T 8sIZ sR Z $j$9sIsR IZ st js js s k s8}j$s Y$R B $s Z s I js YZ8st$IsI R ? st j P T
$ Ak >d EnH Ns } ? s{ ${s8 t $tI R Z{ $Aj s 8sIZ s JZ } B RZ {Z }B $ t t R {sRB Zt B $ t s}? Z ${B et Zts } I$Is {sAsK ts I js `Zt js %$ ts8$ s j RBjIsIB qBtk 7 s , sj$9s Zts Ys9sK ts {tBj? B ${s RB } tI t U R {BtR Zk Zts } ? B R$R {B }B sj 8 ? sj${s JZ PZt{$Bts {B8B }Zj8? Bt I s{ B }s s RZ I? A$j {B s9? Bt p s{$sR s jjs k Zts % 9 } P {T {$BtsIs R tP 8$9B RZ` B }sRs ? s s t BRs jsR hjsR I js ks js s j$R s I RZ} Y? B R =ts s 8sIZ s I Y$ B R }B{B } ? s{ ${sU RZj s I 8sR$sIB } RsIs -} $8 t s I$js s{$Bt R k {Bt s{{$Bt R {Bt jBR {s8A$BR I 8} s Z s $ t Zts j %sIs {BtIZ{ $%$IsI j? { ${s k ? 8${s k R B-$Is {Bt Ps{$j$IsI et ht } B}$ IsI R I Zt 8 sj RB R? I st R$R t{$s {B8B j Y$ B _s s R BR 8 t R R j RZRBI${YB YB8A I Y$ B Ys ? s 8 `B t Z $j$9s B BR 8s $sj R {B8B j s{ B B j $ st$B w5 j k RBt 8? sR j$ BR
<B8A I Y$ B R B B I jBR RZ} Y? B R { sIB }B j ? stI 8 7 st N k Fs{,
YB8A I $ st$B2D JZ }BR t 8 `B R } R s{$Bt R Vj$ tR ej RB
z R$Bt R 8BI tsR I jsR s 8sIZ sR I jBR {sAsjj BR I j 8 I$ %B jsR Ysjjs8BR }B ` 8}jB t jsR R Z{ Z sR }B t{$sIB sR I PZ 9s 8ZR{Zjs JZ s}s { t t j hj8 >Vj$ tR d MEH k JZ st A$ t }s { 8st `s js t$ t i$}j k 7 s s I } BjBt s{$Bt R 8 {? st${sR I jsR - 8$IsI R I j {Z }B YZ8stB {Bt BjsIsR }B j R$8}j 8B%$8$ t B I ? R sR e- tR$Bt R PZ Z ? R ${sR {tBj? B ${s8 t 8? sR {B8}j `sR s}s { t t jBR js BA s ? sh{s
st s js B I t I j I? s t t d ( ZtsR RBhR ${sIsR s 8sIZ sR I {B8As w -B RJZ j BRD R ?
8st s et V}}j R I >d (T 1H I sRs8Zt 7Y$ Bb {Bt% $Is t } j? {Zjs I st$8s{$? Bt
© Los autores, 2001; © Edicions UPC, 2001.
dE;
* $t Bt s e$tR $t
Zts q$ s }BR YBjB{sZR B I j R$ jB yy ej ZRZs $B R s{B8BIs t RZ $t $B $t BIZ{ A s9BR k }$ tsR t ZtsR PZtIsR {ZkBR 8B%$8$ t BR $8$ st h j8 t jsR - 8$IsI R I js s 8sIZ s *$% RBR R tRB R Ps{$j$ st $tPB 8s{$? Bt I j 8ZtIB - $B sj A$ t } B $IB ZRZs $B Ns RBhR ${s{$? Bt I j s $jZ $B JZ$ Zt AZ t sI$ R s8$ t B }s s RZ {B { B 8st `B Ns $I s I R $}B I s 8sIZ sR $t sIsR PZ $t BIZ{$Is }B iBA < $tj $t t js tB% js q B}sR I j R}s{$B >7 s RY$} q BB} R d x H {Zks % R$? Bt P? j8${s wNsR A $ sIsR I j R}s{$B >7 s RY$} q BB} R d HD tB Ys RsA$IB -}jB s BIB RZ }B t{$sj ]BtR $ Zk t Zts R ZtIs }$ j }s s jBR s Z $IBR RBjIsIBR ? {BjsR * RZ {B { s {BtR %s{$? Bt k 8st `B I } tI j }BI Rsj$ %$%B I jsR { Z t sR As sjjsR JZ j$A st {Bt s ZtBR sj$ t? tsR { sIBR I j$A sIsT stIBR t Bt{ R RZ 8 t }B j sZ B }s s I R} s $tR $t BR }ZjR$%BR t j j { B w`ZR $h{? 8sRs{ D eR sR s 8sIZ sR I {B8As s}s { t s8A$? t t js P tB8 tsj tB% js Ns Z s $t 8$tsAj >qY 3B % Gs d xH I FB <sjI 8st R$ ZsIs t js st ? }BIs $I Bj? B ${s I js st $B ej } B}$B <sjI 8st - $ tI j ZRB I I${YsR s 8sIZ sR t RZ tB% js _s9 $t T 8$tsAj >qY 3B % _ s{ d H IBtI {Bt 8}js As sjjsR PZ Z $R sR {ZkBR {Bt tI$ t R jBR RBjIsI$ BR RBt 8 sR {s {sRsR 8 ? sj${sR {Bt BjsIsR s I$R st{$s I RI Zt R Z B AZt, _B Zts % 9 js %$Is YZ8sts }s { %sjB s R 8? sR JZ Zts {BR BRs {tBjB ? s =ts I ? sR ${s RBjZ{$? Bt }s s IZ{$ jBR JZ $8$ t BR I Aj$tIs` t R $}B I s 8sIZ sR {BtR$R t j$8$ts I j {Bt t$IB R I {$ I js } RBts JZ %s I t B BIB sJZ jjB JZ }Z I RZj s %Zjt sAj I `stIB RB R? jB 8? t$8B $8} R{$tI$Aj eR B R t R t{$s iBAB]B} sZtJZ R } {$RB s{js s JZ RZ R sIB htsj tB R %BjZt s $B et Zts Rst $ t s P $ s j s t I }Bj${? s Z }Yk I js {$ZIsI I * B$ R {BR$IB s Asjs9BR =ts s t{$s } $%sIs I R Z $IsI js !]_ {BtR$ Z $8}jst s jBR R BR I j 8sj {YB {Z }B I j s t wZts }s I RZ { ? st B k {s sD t Zts {B8}j `s {s {sRs 8 ? sj${s I PB 8s YZ8stB$I {Bt BjsIs }B B I tsIB { stIB sR? sj }Bj${? s I j PZ Z BU iBAB]B} 7Z 8$R$? BtU R sAj { j B I t k js `ZR ${$s k } B sj $tB{ t eR tZ %B s9B I 8sjY {YB R k I 8s ts R R$t R{ ? Z}ZjBR ts{ t j {$t t js } j? {Zjs I j 8$R8B ? ZjB >d M H eR I jBR }B{BR RZ} Y? B R JZ R Ys B $ $tsIB t j {$t k Ys R$IB sIs} sIB I R}Z? R sj {? B8${ <s {Bt sIB {Bt Zts R $ I I$AZ`BR st$8sIBR k YsR s B s I qz >d nH 7Z R Z{ Z s 8 ? sj${s Ys{ I ? j Zt R 8Zk }BI BRB R$t jBR } BAj 8sR I {Bt`Zt{$? Bt I jsR I$P t R }s R 8 {? st${sR {Bt jsR YZ8stsR I jBR B BR YB8A R {$A t? ${BR JZ Y 8BR %$R B VZtJZ s I$P t{$s I 8Z{YBR I jBR RZ} Y? B R {j? sR${BR tB R B sj8 t $t% t{$Aj et jsR R } j? {ZjsR JZ }B j 8B8 t B 4 `st RZR s{{$Bt R `ZR ${$ sR wiBAB]B} >d M H iBAB]B} 1 >d (H iBAB]B} n >d ;HD {$A st BR Bj} R {B8B Is et js Z ?j $8s t s R } 8$ $t{jZRB j jZ`B I jst9s 8$R$j R gk I %Bjs 7ZR JZ R tRB R B ?} ${BR {s}s{ R I {s} s js sI$s{$? Bt $tP s B`s k RZR 4 `BR wtB $ t }ZjRB sR? R {s}s9 I s}Zt s {Bt RZ s 8s {Bt Zts } {$R$? Bt $t$ ZsjsAj D RBt B BR I RZR {BtB{$IBR s $AZ BR WsIs JZ tB R Ysjj t jBR j? 8$ R I jB s9BtsAj NBR } BAj 8sR -$R t{$sj R I R R 8 I$B 8 {? st${B 8 I$B YB8A BIB }Bj${? s $ t t Zt P t t jsR tB% jsR WB GB8st B t >d ;;H I ]s Y $t N BB k 5+Z$? t2 >GYB2 d xMH I Vj $R ZI kR et ? R s Z ?j $8s jj %sIs s8A$? t s js }st sjjs >d ;H Zt {$ t ? h{B tB s8 ${stB RZP Zt $Aj s{{$I t t iZR$s Ns R st{$s t R }s? R k RZ B tB {Bt BIs Zts R $ I } ? B R$R j %st st js RBR} {Ys RBA RZ % IsI s $I t $IsI
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
@-N
3$ n d1 _s YB8A }s 8? sJZ$tsU iBAB]B} j A s9B 8 {? st${B I js j k
+Z$9? sR t j PZ Z B js PB 8s JZ js YZ8st$IsI t s I -}jB s tZ %BR 8ZtIBR R AsR tB st B t js {BjBt$9s{$? Bt B sPB 8s{$? Bt I j t B tB R$tB t js stRPB 8s{$? Bt P? R${s I j R YZT 8stB }s s RZ sIs} s{$? Bt sj 8$R8B =ts tB% js 8Aj 8? s ${s t R R t $IB R <B8B _jZR > st _jZR d EH I 3 I $, _BYj et jjs R I R{ $A js {Bt% R$? Bt JZ s t$% j P? R${B -} $8 t s Zt R YZ8stB }s s }BI %$%$ t s R$t JZ$}BR R} {$sj R k R stsj$9st s8A$? t jBR P { BR }R${Bj? B ${BR JZ {Btjj %s 5]? B8B R jj %s s {sAB R } B{ RB I sIs} s{$? Bt2 "7Z}Bt s8BR JZ R B8s j 8BI jB I js R Z{ Z s YZ8sts k R sj s }s I RZ JZ$}s8$ t B B}{$Btsj WB Ysk tsIs JZ R}$ s t s VR? }Z R R - s t jBR }Zj8Bt R I js R Z{ Z s YZ8sts k R RZR $ Zk t }B R$R 8sR 8${ B8$ts Z $9sIBR I t s{$? Bt I B-? tB 7 t { R$ s t ? s }s s RB } B js t ? s R - s I j I$R st 7Bj Ns Rst R ? Zt js R Z{ Z s YZ8sts Y %$ ? s 8Zk A$ t }Z R R j$8$ts js Rst sj 8 tBR I jsR - 8$IsI R k I jsR s ? sR RZT ZR{ZjBRD k R } h{$sj R w{BtR Zk tIB A s9BR k }$ tsR s{{$BtsIBR }B 8B B R t % 9 I }B 8? R %s Zt }B{B I Rst R? BjB }s s j { A B }s s sj$8 t s jB k {sj t s jB =t {Z }B YZ8stB tB 8sj t { R$ s {B8$Is } B R$ js 8skB }s I jBR 8? ZR{ZjBR R RZR $ Zk t }B 8? sJZ$tsR js {st $IsI I {B8$Is t { Rs $s R ? s 8Zk } JZ K ts > H 5ej s Zs2 Os tB R t { Rs $s -{ } B R$ R } BIZ{ t }? I$IsR t js 8sJZ$ts $s > H 5Ns sI$s{$? Bt2 ej {Z }B I A R } B $IB
© Los autores, 2001; © Edicions UPC, 2001.
@--
* $t Bt s e$tR $t
}B Zts }$ j s $h{$sj _s s 8st t j {sjB k jB s Zts AZ ts %$R$? Bt R } {$RB s8}j$s js RZ} h{$ {B }B sj }s s {$A$ 8? sR t ? s k 8}js9s jBR B`BR }B R Z{ Z sR 8 {? st${sR > H 7$ s Zt R YZ8stB R j Ys{ t BIsR RsR {BRsR jB JZ JZ Is ks tB R } {$Rs8 t Zt R YZ8stB eR Zt YB8A }jZR st {st $IsI I j 8 t BR I 8 sj ej YB8A R {Bt%$ sR? t Zt B st$R8B {$A t? ${BU Zt {kAB " eR $}B I {kAB R sIs} sIBR }s s js -}jB s{$? Bt I B BR 8ZtIBR jB t{Bt s8BR s8A$? t t j js B et{Z t B {Bt IZRs >V $t b$ Y IZRs d dH I V YZ ] ]js ,
n x
et AZR{s I j YB8A $t%$R$Aj
WB R Zt RZ} Y? B t j R t $IB R ${ B {B8B sJZ jjBR {Bt JZ$ t R tBR Y 8BR }sR sIB s jB js B I R {s}? ZjB sZtJZ RZR }BI R A$ t }BI ? st sZ}s jB sj !j$8}B I jBR 8$R8BR 7 s s I j YB8A $t%$R$Aj Ns $t%$R$A$j$IsI R $t{jZk t js js s j$R s I RZ K tBR k stY jBR I j YB8A `Zt B s js }BR$A$j$IsI I %Bjs {B8B jBR }? s`s BR B sj{st9s js $t8B sj$IsI _s s jBR {Z $BRBR R s R js YsA$j$IsI $I sjU % R$t R %$R B t s k Rsj$ I {ZsjJZ$ jZ s R$t t JZ Ys{ jB }B Zts }Z s wtB 8sj8 t js $t%$R$A$j$IsI {Btjj %s js } B}$ IsI I }BI s s% Rs jsR }s I RD { 7Bt 8Z{YBR k %s $sIBR jBR 8? BIBR $I sIBR t js h{{$? Bt }s s {Bt% $ s Zt $tI$%$IZB tB 8sj B s Zt BA` B t $t%$R$Aj * R s{$sIs8 t }BI 8BR s%st9s JZ t$t ZtB I jjBR PZt{$Bts 8? sR sjj? s I j R ${ B s ?8A$ B I js tB% js j js B B js } j? {Zjs IBtI R I R{ $A VZtJZ sj ? Zt j { B }Z I R Z$ } tRstIB JZ jBR YB8A R $t%$R$Aj R -$R tU jB JZ RZ{ I R JZ %$I t 8 t gtB }BI 8BR % jBR ws Z8 t B $ Zsj8 t s}j${sAj s %$s` BR Bt sj ZtBR I j $ 8}B B R 8}$ tBR sj$ t? tsRD * BIsR PB 8sR }sRs 8BR s {Bt $tZs{$? I jBR } B{ I$8$ t BR 8? sR B $ $tsj R $8s $tsIBR s sj P { BU 6 =ts 8st s I {BtR Z$ Zt {$ B {s ? s{ $t%$R$Aj R sj{st9s j R s ZR I R sJZ jjB JZ tsI$ I R s % 5WB Yst tB sIB sj Zts % 9 Zts R tRs{$? Bt I R $}B st sj Zts % t st$jjs
I js sI8$t$R s{$? Bt2 5WB R js 8$R8s R$ Zs{$? Bt JZ %$% Zt 8$tZR%? sj$IB B Zts } RBts 8skB {ZstIB RZA sj sZ BA? ZR k BIB j 8ZtIB I$R$8Zjs st R I j %st s R k BP { RZ sR$ t B2 7Bt R$ Zs{$Bt R {B $I$stsR R$8$js R s jsR }jst sIsR t jBR js BR qY ]BZt k BP Y $tI >d EnH I *s8Bt t$ Y B qB 7 Y yt%$R$Aj st >d EnH I iBA 7$j% A IBtI jBR { $8$tsj R RBt R$8}j 8 t $ tB sIBR }B Zts RB{$ IsI JZ YZRs % jBR } B%B{stIB RZ st ZR $s k RBj IsI * t B I R $}B I $t%$R$A$j$IsI I tI t{$s RB{$Bj? B ${s B }R${Bj? B ${s 8? sR 8 sP? B ${s JZ sj }BI 8BR $t{jZ$ js $t%$R$A$j$IsI jB sIs 8 I$st js sj s{$? Bt I js %$R$? Bt I jBR I 8? sR _s s Zt j? }s s {B8B jBR JZ I R{ $A VjP I R t RZ tB% js ej YB8A I 8Bj$IB >qY * 8Bj$RY I st d x1H I A RZj s 8Zk R t{$jjB AjBJZ s B AB s js } { }{$? Bt JZ B s } RBts }Z I t I ? j NB 8$R8B JZ }Z I Ys{ Zt Y$}tB $9sIB {B8B }B ` 8}jB js sj$ t? ts I - sK tsR {BR Z8A R I js } j? {Zjs _jst s Rst $ t B >+Z t BP jBBI d EEH B {ZsjJZ$ } R t sIB I j 8 I$B j %$R$%B JZ R } {$ {Bt RZ sZI$ t{$s Z{YsR % { R Zt IBt I R sR {s s{ ? R ${sR }Z I BA t R }B $t { R$? Bt I$%$ts B 8? s ${s WB 8sj8 t }B 8 I$s{$? Bt I s $jZ $BR Z BA` BR {Zks }BR R$? Bt {B8}B s j }BI I R $t%$R$Aj s %BjZt sI 7Bt ` 8}jBR I t B I Zt ? t B {Bt t $IsI } B}$s {B8B j Pst ? sR ${BU j {sR{B JZ jZ{ j Y? B 8$ Bj? B ${B _ R B t js } j? {Zjs 3Z $s I q$ st R >]jsRY BP Y q$ stR d M(H js {s}s I 7$ P $IB t js Rs s $t${$sIs {Bt NBR t$A jZt BR >*$ W$A jZt t d 1;H k j
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
dE
R{ZIB I BAR{Z $IsI Z $j$9sIB }B 7$8AsI t ej %$s` Pst ? sR ${B I 7$8AsI >qY pBjI t zBks BP 7$8AsI d ;H NBR st$jjBR I j }BI JZ s}s { t t j } RBtsj Zt$% RB $t% t sIB } FBYt i i qBj,$ t t ej R K tB I jBR st$jjBR >d x;TxxH }BR$A$j$ st s8A$? t t B BR }BI R j I js $t%$R$A$j$IsI
NBR Pst sR8sR RBt }B I ht${$? Bt t $IsI R JZ B9st I js $t%$R$A$j$IsI {B8B P { B R {ZtT Is $B I RZ } B{ I t{$s I j 8? sR sjj? s sZtJZ }s s I tB s RZ } R t{$s 8Z{YsR % { R R tBR } R t t % R $IBR {Bt R? sAstsR Ajst{sR B sIB} t js PB 8s YZ8sts _ B j } {$B s }s s }s s {BtR Z$ R $t%$R$Aj {B8B Zt Pst sR8s R sj BU g R t { Rs $B 8B $ } $8 B WB }s { s s R }Z R I Zt 8? BIB I 8sR$sIB {B8 tIsAj NBR R$ 8} $tJZ$ st R %s8}$ BR tB RBt $t%$R$Aj R sZtJZ s8A$? t }BR t Zts RB } tI t }B RZ $t{Bt Z t{$s } B}$ IsIU js I tB R 4 `sIBR }B jBR R} `BR NBR BA` BR RBt %$R$Aj R }B JZ 4 `st js jZ9 JZ j R jj s jBR R} `BR tB Ys{ t 8? sR JZ 4 `s R s jZ9 JZ PB 8s jsR $8? s t R I jBR BA` BR 5jZ B2 ! B 8$R $B 8? sR }s s j s R tsj I j {BtI * ? s{Zjs i RZj s $tt { Rs $B s}Zt s JZ st B Pst sR8sR {B8B %s8}$ BR tB $ t t 8? sR t $IsI sj JZ js I jBR R R $8s $ts $BR k JZ I A t } 8st { t j jZ s JZ j R {B R}BtI U j I js Pst sR? sdd I B ts Zt BA` B $t%$R$Aj R }$t s jB I j 8$R8B {BjB JZ j PBtIB ej {s8Z4s` B {BjB s{$? Bt R sR$IZs8 t 8}j sIB }B 8Z{YBR st$8sj R k }jst sR }s s {BtR Z$ }sRs I T Rs} {$A$IBR }B I$P t R 8B $%BR wI P tRs %$ $jst{$s D ej {BjB }js sIB I jsR R{s8sR I jBR } { R R Zts I P tRs P t s js s8 ts9s I jsR s% R I s}$K ts k I jBR I } IsIB R 8s $T tBR Ns RZ} h{$ I j s Zs R {B8}B s {B8B Zt R} `B {ZstIB R BAR %s {Bt js $t{j$ts{$? Bt t { Rs $s st B }B t{$8s {B8B }B I As`B I js 8$R8s wP t? B8 tB I js 4 -$? Bt B sj I s{$j8 t j {BjB 8 ? sj${B jBR skBR I jZ9D et js RZ} h{$ A $jjst I j s Zs R {BtPZtI P? }js sIB I j } 9 NsR 8 IZRsR RBt $t{BjB sR k stR}s t R k }B st B } ? s{ ${s8 t $tT %$R$Aj R t RZ 8 I$B NBR {s8Z4s` R 8$j$ s R $t t st $8$ s s8A$? t s js ts Z sj 9s =t s%$? Bt }$t sIB {Bt 8st{YsR 8s Bt R B % I R R {BtPZtI {Bt js RZ} h{$ R {ZstIB R BAR %s I RI 8? sR s $As y Zsj8 t js }s $tP $B I sj ZtBR s%$Bt R 8$j$ s R R }$t s I j 8$R8B {BjB JZ $ t j {$ jB NBR I$ $ $Aj R 9 }} j$t 8}j sIBR }B jBR sj 8st R IZ st js y pZ s ZtI$sj } R t sAst RZ} h{$ R I sjZ8$t$B A $jjst JZ 4 `sAst j PBtIB I j {$ jB k jsR tZA R * RI Zts {$ s I$R st{$s RZj sAs 8Zk I$P? {$j I R{ZA $ RZ } R t{$s ej ZRB I R} `BR t {s`sR k s 8s $BR I IBAj PBtIB R P {Z t s8A$? t t 8Z{YBR Z{BR I 8s $s I R{s8B B I BA` BR } B { B s
6 i {Z $ s js {$ t{$s }s { R s 8? sR s{B I {Bt jBR $ 8}BR s{ Zsj R Ns 8st s 8? sR P? s{$j
6 7$ {BtR Z$8BR JZ jsR BtIsR jZ8$tBRsR R I PB 8 t k BI t sj BA` B t {Z R $? Bt tB YsA ? s
4 -$? Bt }B }s I j 8$R8B tB jj s ? s jZ9 s jBR B`BR I j BAR %sIB k t {BtR {Z t{$s j BA` B } 8st { ? s $t%$R$Aj 7sA 8BR JZ {ZstIB js jBt $ ZI I BtIs R 8? sR stI JZ j s8sK tB I j BA` B js BtIs R$ Z RZ sk { B $s R$t R I$R} RsIs }B j BA` B NBR s ? B8BR tB RBt %$R$Aj R {Bt jZ9 tB 8sj }B JZ $ t t Zt s8sK tB 8 tB JZ js jBt $ ZI I BtIs I js jZ9 %$R$Aj wI j B I t I d( d( 8 }B ZtBR x d( 8 R} { $%s8 t D 7 Yst } B}Z R B
VZ B R {B8B V8A BR $ { <Bbs I _ NB% { sP pZk I sZ}sRRst B eI s Vjjst _B t B BR s8A$? t R Yst s{ {sIB sj 8s I RI R s } R} { $%s t js BR JZ AB I st jBR I$PZRBR j? 8$ R -$R t R t js Pst sR? s RBA ts Z sj k js {$ t{$s h{{$? Bt dd
© Los autores, 2001; © Edicions UPC, 2001.
dEM
* $t Bt s e$tR $t
8 {st$R8BR k -}j${s{$Bt R $t% BR? 8$j R }s s `ZR $h{s js }BR R$? Bt I j }BI I js $t%$R$A$j$IsI }B }s I sj ZtBR Y? B R k 8sj%sIBR I js h{{$? Bt qBIBR jjBR AsRsIBR t js $I s I I PB 8s js sk { B $s I jBR skBR I jZ9 I 8st s JZ R sj ` t I j BA` B ej {Z RB 8? sR RB{B $IB R j I Z $j$9s Zt {s8}B j { B8s t? ${B }Z R B JZ {BtR Z$ {s8}BR s%$ s B $BR $t tRBR t sK ts {$ sR I$h{Zj sI R * Y {YB t } R t{$s I {s8}BR s%$ s B $BR 8Zk stI R js sk { B $s I js jZ9 R {Z %s NsR BtIsR jZ8$tBRsR } B{ I t R I PZ t R I jZ9 {B8B jsR ZjB R jjsR R {Z %st {ZstIB }sRst }B jsR } B-$8$IsI R I Zts st 8sRs {B8B j 7Bj w]s}? ED =t P { B } JZ K tB t {B8}s s{$? Bt {Bt j %sjB I js 8sRs JZ R t { R$ s }s s } B%B{s jB ej 7Bj $ t Zts 8sRs I 1 d(n( , 8$ t sR JZ {ZsjJZ$ } RBts I {B8}j -$? Bt tB 8sj B D VR? JZ {B8B tB jj s s jBR {$ t ,$jBR wsZtJZ jj % t{$8s Zt %$R BRB s` I RZ} Y? {B8} tI ? st RZj s 8Z{YB 8 tBR } RsIB jj %s t j ABjR$jjB {ZsjJZ$ B B I$R}BR$ $%B 7ZRst i${Ys IR js {Y${s $t%$R$Aj JZ PB 8s j JZ$}B I RZ} Y? B R I NBR ]Zs B 3st ? sR ${BR {BtR$ Z RZ }BI s{$sR sj Y {YB I JZ R {s}s9 I } BIZ{$ Zt j %sIB {s8}B j { BT 8s t? ${B s RZ sj I IB gs AsR I {stsj$9s js sI$s{$? Bt {? BR8${s et js R $ I qz qY yt%$R$Aj st >d xT EH j } B s Bt$R s Ys YsjjsIB Zt 8? BIB }s s jZA ${s jsR 8Bj? {ZjsR I RZ {Z }B 8 I$st {s8}BR j { B8s t? ${BR NsR BtIsR jZ8$tBRsR RAsjst j$ sj8 t t sJZ? jjsR k s s%$ Rst RZ {Z }B R$t R 4 `sIsR VR? {BtR$ Z Zts $t%$R$A$j$IsI } 8sT t t s js JZ Zt s8$ B {$ Z`stB }j? sR ${B }BtI ? s BR B sj { s }s s ? j Zts 8? sR{s s {Bt t R $ I RZ {s s } $t%$R$Aj w{BRs JZ j R} { sIB s sI { D ej } B s Bt$R s I js s8A$? qz ej YB8A $t%$R$Aj >p 8$t$ st d H {Bt $tZs{$? Bt I js st $B {B8B {BtR {Z t{$s I js -}BR${$? Bt s js sI$s{$? Bt wgsY JZ? R ? s I 8Z{YBR I R BR }BI R R$t RZ -$R t{$s D }Z I { s Zt {s8}B 8s t? ${B s RZ sj I IB R$8$js sj I js {Y${s $t%$R$Aj VZtJZ t R {sRB }s s }Bt j jsR {BRsR 8? sR I$P? {$j R $t BIZ{$ sj B 8? sR I 8B{$? Bt t jBR }$RBI$BR RZ R sIB R} {$sj R $t R sAj U R? BjB }Z I } 8st { $t%$R$Aj IZ st JZ$t{ 8$tZ BR {sIs I? s $ 8}B {Bt BjsIB }B Zts R} {$ I jB` I }ZjR s JZ jj %s t RZ 8ZK t {s et s8AsR R $ R jBR } RBts` R } B s Bt$R sR s{sAst sAs`stIB {B8B s t R R { BR JZ }s { R j 8 `B 8}j B JZ }Z I {BtR Z$ Zt YB8A $t%$R$Aj NBR 8$Aj R k }BI BRBR sj$ t? tsR I jBR hj8 R * } IsIB k RZ R {Z js * } IsIB 1 {Z t st {Bt Zt $8} R$Btst s R tsj A? j${B st B BP tR$%B {B8B I P tR$%B = $j$9st Zts R} {$ I {s8Z4s` s $h{$sj $t{B }B sIB t RZR s 8sIZ sR JZ PZ 9s s js jZ9 s {Z %s R sj I IB I RZR {Z }BR ej 8 {st$R8B tB I A R 8Zk h{$ t ks JZ {ZstIB R I R}js9st jsR BtIsR jZ8$tBRsR }Z I t } t s k RBt t }s 4 `sIsR } BIZ{$ tIB $t P t{$sR JZ Ys{ t JZ R st }s {$sj8 t %$R$Aj R sZtJZ I PB 8s sj B AB BRs 57 s s I Zts I P t{$s Ys{$s j R} { sIB 2 _$ tR t R$tB t jB I$P? {$j JZ R sj$9s Zts } j? {Zjs {Bt R R Z BA` BR JZ tB R % t _ R s js RBhR ${s{$? Bt I jBR 8 {st$R8BR I R{ $ BR RZj s ? s js $%s8 t R t{$jjB I { s js } R t{$s I R BR } RBts` R qBIBR jBR 8? BIBR }s s {BtR Z$ js $t%$R$A$j$IsI {$ sIBR Ys{ t ZRB I Zts PB 8s B I B s I j {s8}B 8s t? ${B k ? R }Z I I { s R P? s{$j8 t {Bt Zts gR$8}j A ? Z`Zjs =ts I$h{Zj sI s t t {BtR$I s{$? Bt R$ } R s BIB jB I${YB sj Z$ t {BtR$ Z B ts R $t%$R$Aj Z $j$9stIB R 8? BIB R JZ R$ t tZ R B sP? st $t% t B $I s8BR Zt 8? BIB I $t%$R$A$j$IsI I 8sR$sIB P { $%B {BtR Z$ 8BR I R%$s tB R? BjB js sI$s{$? Bt jZ8$tBRs $t{$I t R$tB s8A$? t {ZsjJZ$ B B $}B I sI$s{$? Bt JZ jj Z VR? }Z R js } %$R$Aj 8Z }B {Bt js{$? Bt tB R Zt } j$ B 8 tB
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
@-
ej s8sK tB I jBR BA` BR {stI$Is BR s R $t%$R$Aj R tB $8}Bt t$t ? Zt $}B I R ${{$? Bt s js $8s $ts{$? Bt V Zts R{sjs 8skB tBR t{Bt s8BR {Bt ts% R JZ$}sIsR {Bt }st sjjsR I $t%$R$A$j$IsI V } Rs I BIB jBR Z$Bt$R sR R s}$sIst I % 9 t {ZstIB I jBR RZP $IBR R} { sIB R k }Bt t {B s s RZ Pst sR? s I RsPB sIs et js } j? {Zjs 7 s q , yyyT et AZR{s I 7}B{, >7 s q , yyyT qY 7 s {Y PB 7}B{, d M;H j R{ZIB I $t%$R$A$j$IsI I js ts% ,j$t Bt JZ R}? s sj et } $R tB R P { $%B {ZstIB ? R s R t{Z t s { {s I Zts 8sRs stI {B8B js I j }jst s p? t R$R ! sR % { R t {s8A$B jBR -{ RBR $8s $ts $%BR Ist sj sR {Bt jsR }BR$A$j$IsI R I js $I s B $ $tsj et ej -} $8 t B 3$jsI jhs >qY _Y$jsI j}Y$s e-} $8 t d M;H j BA` $%B R Ys{ $t%$R$Aj R sj sIs t 8$ B jBR As {BR I js 4B s tB s8 ${sts I js yy pZ s ZtI$sj ej R$R 8s PZt{$Bts I 8st s st h{$ t JZ Zt }B ss%$Bt R `Zt B s RZ $}Zjs{$? Bt tB st R? BjB I Rs}s { I j sIs R$tB JZ jB Ys{ s8A$? t I js %$R s et js tB% js N Bt VtsjB Z I i t? *sZ8sj R 8Z R s Zts $Rjs JZ R $t%$R$Aj NBR 8$t sj R I RZ RZARZ jB RBt js {sZRsU RBt 8s t? ${BR k } BIZ{ t Zt } hj {$ {Zjs I j? t sR I {s8}B 8s t? ${B gJZ jB I R%? s BIB 7$ BIB Psjjs R$ 8} }Z I {Z $ R s Zts t$ 8? s ${s 8? sJZ$ts I js $t%$R$A$j$IsI {B8B js JZ }BR j * s ,B% k JZ R Z $j$9sIs }B 3jsRY pB IBt ! A$ t Ys{ ZRB I j R$R 8s I $t%$RB{$t Z Bt R I JZ R ? s JZ$}sIB j sAB sIB % t$IB s RZ} Y? B {BtB{$IB {B8B j 3st sR8s I j R}s{$B ! BR I$R}BR$ $%BR 8 {? st${BR }s s %Bj% R $t%$R$Aj jBR t{Bt s8BR t js BR {B8B Vjj 3B NB% >d E1H I Vj $R ZI kR IBtI R I R{ $A j 8}j B I Zt 8stB`B I hA sR B ?} ${sR }s s I R%$s js jZ9 sj I IB I js } RBts R$ ZsIs t j $t $B =ts hA s B} ${s tB R 8? ? sR JZ Zt ZAB I %$I $B stR}s t JZ } 8$ js stR8$R$? Bt h{$ t I Zt Ys9 I jZ9 s{$sR s js 4 -$? Bt B sj t RZ RZ} h{$ $t ts WB -$R }? I$Is I t ? s jZ8$tBRs }B sARB {$? Bt I jsR }s I R I js hA s NsR hA sR B ?} ${sR RBt I s8}j$B ZRB t s}j${s{$Bt R 8? I${sR {B8B RBtIsR }s s -s8$ts B ? stBR $t tBR k RBA BIB t R$R 8sR I {B8Zt${s{$Bt R }s s js stR8$R$? Bt I R K tsj R j { B8s t? ${sR Ns jZ9 } B{ I t I Zt BA` B R }Z I } B}s s s s%? R I Zt {Bt`Zt B I hA sR I %$I $B - 8sIs8 t htsR I YsR s sj ZtsR { t ? R$8sR I 8$j? 8 B I I$? s8 B ]sIs hA s sR8$ sj B B - 8B I j 8stB`B js $8s t I Zts } JZ K ts $? Bt I j BA` B k j {Bt`Zt B PB 8s RZ $8s t VR? jsR hA sR B} ${sR R sR 8 `st s jsR }s R {BtR $ Z $%sR I j B`B {B8}Z R B I jBR $tR { BR wB8s $I$BRD ? 5+Z? R BAR %s ? s t j jZ s IBtI R t{Bt sR Zt YB8A $t%$R$Aj JZ$}sIB {Bt j s $jZ $B $I sIB }B ZI kR2 ej P { B t sj R ? s JZ R % ? st jsR {BRsR I PB 8sIsRU {ZsjJZ$ skB jZ8$tBRB RZj s I R%$sIB }B js hA s B ?} ${s k 8 t Zt jZ s {B R}BtI$ t B tB sj B B jsIB I j I$R}BR$ $%B VR? JZ I R}Z? R I BIB tI ? s8BR Zts $8s t AB BRs k I$PZ8$tsIs t j jZ s IBtI R} s ? s8BR t{Bt s sj RZ` B ej R$ Z$ t 8? BIB {BtR$R t sj s js R Z{ Z s JZ? 8${s I j BA` B }s s %Bj% jB stRT }s t s jsR BtIsR jZ8$tBRsR =t } Is9B I %$I $B RZ8 $IB t s Zs R } ? s{ ${s8 t stR}s t k }Z I }sRs I Rs} {$A$IB t R 8 I$B eR B R I A sj Y {YB I JZ j %$I $B $ t Zt ? tI${ I P s{{$? Bt @ R$8$js sj I j 8 I$B JZ jB BI s NBR skBR I jZ9 $t{$I t R 6
NsR BtIsR j { B8s t? ${sR I {ZsjJZ$ P {Z t{$s %$s`st }B j %s{? B s js 8$R8s % jB{$IsI et Zt 8 I$B 8s $sj js % jB{$IsI I } tI I js P {Z t{$s I js BtIs } B R R$ 8} $tP $B s js % jB{$IsI I js jZ9 t j %s{? B Ns js{$? Bt t js % jB{$IsI I js jZ9 t j %s{? B k t B B 8 I$B R I tB8$ts ? tI${ I P s{{$? Bt NBR ? tI${ R I P s{{$? Bt I j %$I $B k I j s Zs RBt {sR$ $ Zsj R
@
© Los autores, 2001; © Edicions UPC, 2001.
d (
* $t Bt s e$tR $t
jB s s%$ Rst R$t I R%$s R wtB Ysk P s{{$? BtD t$ R 4 `sIBR
qs8A$? t }Z I B ts R t
$t%$R$Aj Zt BA ` B stR}s t BI ? stIBjB I }s I R JZ 4 ` t js jZ9 I 8st s Zt$PB 8 sZtJZ j ? tI${ I P s{{$? Bt I j 8 I$B k I j BA` B R st I$P t R JZ I tB t RZ } R t{$s j BA` B R ? s $t%$R$Aj 7$t 4 `BR t$ RB8A sR
= $j$9stIB R s } B}$ IsI 5}BI ? s {BtT
R Z$ R JZ Zt {Z }B YZ8stB PZ R {B8}j s8 t stR}s t t j s$ 2 }$ j R I A$IB s js -$R t{$s I Zt }$ 8 t B jjs8sIB } RBtsR BR
sjA$tsR
8 jst$ts
ej {BjB I js
k s js $ $ s{$? Bt Rst Z? t s NsR
$ t t Zts }$ j 8? sR {js s s {sZRs I Zt I? h{$ I 8 jst$ts k I B BR }$ 8 tT _s s
et ? }B{sR }sRsIsR t js s $R B{ s{$s R }ZRB I 8BIs t js }$ j 8Zk {js s
{BtR Z$ Zts }sj$I 9 - 8s R } B%B{sAst st 8$sR s }s I 8AsIZ ts R {Bt }Bj%BR k { 8sR I$% RsR g]Z? st j `BR JZ Is R B I js 8BI ts 8BIs I j
A Bt{ sIB } P { B
qs8A$? t
{$ sR tP 8 IsI R I js }$ j B js -}BR${$? Bt s js sI$s{$? Bt } B%B{st js s}s ${$? Bt I 8stT {YsR AjstJZ {$tsR et j {sRB Y$}B ? ${B I BA t tB ks Zts }$ j Ajst{s R$tB {B8}j s8 t stR}s t sj stIB jBR } B{ RBR {B8 t sIBR JZ {Bth t s js }$ j YZ8sts RZ {BjB {s s{T ? R ${B j RZj sIB R ? s Zt R YZ8stB {Bt jBR 8? ZR{ZjBR k j RJZ j B %$R$Aj R B sj8 t I R} B $IB I js sI$s{$? Bt Zj s%$Bj s I js jZ9 RBjs
_s s $ 8? sR sjj? s k {BtR Z$ JZ j `$IB YZ8stB 8? ZR{ZjBR k YZ RBR $t{jZ$IBR R B t $t%$R$Aj Ys ? s Psj s JZ Z%$ R j 8$R8B ? tI${ I P s{{$? Bt JZ j s$ JZ jB BI s < A p G jjR I Rs Bjj? B R s $I s t RZ tB% js
sj % 9 }B js tB% js I eIbs I _s $ {Y j
ej YB8A $t%$R$Aj qY ] $R sj st
>qY yt%$R$Aj st dM H $t4Z t{$sIB >dMMdH eR{ $A < p G jjRU
"VJZ jjB tB s Zt 8? BIB s Zts $I s JZ }BI? s {BtIZ{$ s Zt 8? BIB s{$sR sj {Zsj R ? s }BR$Aj R$t {s8A$s t$t Zts B s } B}$ IsI I js 8s $s -{ } B t sj ZtsR B{sR$Bt R j {BjB 8BI$h{s j ? tI${ I P s{{$? Bt I Zts RZAR st{$s R? Bj$Is B j? JZ$Is YsR s {BtR Z$ BA t j I j s$ t jB JZ s sK t s htsj$IsI R } ? s{ ${sR" Ns $t R $? Bt I I$P t R s{ $%BR JZ? 8${BR k js -}BR${$? Bt s jBR P { BR j? { ${BR I IBR } JZ K tsR I$ts8BR } B%B{s js } B R$%s $t%$R$A$j$IsI I j } B s Bt$R s Fs{, p $^t _B{BR sK tBR I R}Z? R t d dd j sts B8$R s sj 8? st z 7}sj YBj9 Y$9B sj$IsI R sR $I sR sj 8 tBR t jB JZ s sK t s B st$R8BR 8Z BR ejsAB ? B Zt } B{ I$8$ t B }s s {BtR Z$ } }s s{$Bt R stR}s t R I `$IBR st$8sj R VZtJZ R B {js B R ? s JZ Is s? Zt j `BR I js Pst sR ? s I G jjR _B Zt jsIB R t { Rs $B } $8 B Zt 8? BIB }s s j$8$ts j {BjB I BIsR jsR }s R I j B st$R8B R$t JZ RZR PZt{$Bt R R % st sj sIsR _B B B jsR } }s s{$Bt R {BtR Z$IsR }B R sts B8$R s B {B8B jsR JZ YBk t I? s R 8}j st t A$BjB ? s B t 8 I${$ts RBt stR}s t R } B $t%$R$Aj R R? BjB 8$ t sR R t{Z t st RZ8 $IsR t jBR 8 I$BR j ? JZ$IBR {B R}BtI$ t R tB sR? t j s$
ej ? -$ B I js } j? {Zjs
ej YB8A $t%$R$Aj
{Bt ZtBR RB } tI t R P { BR R} {$sj R }s s js
? }B{s Is ? s }$ s tZ8 BRsR R {Z jsR %s $s{$Bt R } B R$%s8 t 8 I$B{ R I j 8$R8B 8s JZ -}jB st j hj? Bt I js $t%$R$A$j$IsI et jsR 8? sR I $t s I } j? {ZjsR {sA I R s{s U
B tB I j YB8A $t%$R$Aj V t $t%$R$Aj GB8st d ;(H
>qY yt%$R$Aj st i Z tR d n H >yt%$R$Aj V t d ;1H k
Ns 8Z` $t%$R$Aj Ns % t st9s I j YB8A $t%$R$Aj
ej
>qY yt%$R$Aj >qY
qY yt%$R$Aj st js } j? {Zjs
yt%$R$Aj st:R i % t d ;;H
V jsR JZ {sA RZ8s R $ R I j %$R$? Bt {B8B js A $ ? st${s
IBtI j $tPB ZtsIB } B s Bt$R s 8}j s RZ $ 8}B t AZR{s Zt st ? IB B
JZ jB I %Z j%s s js tB 8sj$IsI k I }sRB {B8As $ j { $8 t sj R $jB I jBR RZ} Y? B R I Z tB O jsR R $ R tB s8 ${stsR ks {$ sIsR ej BAB
_jst s } BY$A$IB
iBAAk
Ps8BRB s{$sR s RZ s}s ${$? Bt t
PsA ${s Zt s{ $%B j? JZ$IB JZ } 8$ s RZ `B% t s{B8}sK tst
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
d d
3$ n dn =t {$ t ? h{B Fs{, p $^t R $tk { s IZ st Zt 8 R Zts IBR$R I$s $s I Zt } }s sIB js 8BtB{s? ts JZ {Bt $ t t B BR } BIZ{ BR Zts RZAR st{$s Z $j$9sIs }s s AjstJZ s `$IBR ]BtR{$ t I RZ PsAZjBRB }BI R {Bt%$ s }s I $t%$R$Aj t Zt 8st? s{B JZ JZ$ {B8B BIB %$jjstB JZ R } {$ IB8$ts j 8ZtIB {B8 $ tIB }s s jjB BIB $}B I P {YB ? sR {Bt sARBjZ s $8}Zt$IsI ]Bt % tIsR sj I IB I RZ {Z }B $t t s I$R$8Zjs RZ } {Zj$s ts Z sj 9s sZtJZ htsj8 t j sR B I js B I RZR YZ jjsR RBA js t$ % } 8$ s js }Bj${? s s{sAs {Bt RZ } B8 IB s {s s I %$jjstB eR R j s Z8 t B I js 8s $R sj % R$? Bt P? j8${s I js tB% js I G jjR ej YB8A $t%$R$Aj >qY yt%$R$Aj st d nnH et R PB B s8s I js {$t s j } B s Bt$R s s}s { s }Zt B I I R{ZA $ RZ $I t $IsI st RZR s ? Bt$ BR {Bt{$ZIsIstBR
} I j {BjB I RZ {Z }B t qY yt%$R$Aj Bk >d x H et R {sRB s8A$? t RZ B}s R {Bt%$ t $t%$R$Aj s{$sR sj {s8}B j { B8s t? ${B JZ s}s {? s {B8B P { B R {ZtIs $B t js sj s{$? Bt RZP $Is }B RZ B st$R8B z R$Bt R 8? sR R$8}j R I $t%$R$A$j$IsI R t{Z t st t j js B I Fs{, NBtIBt qY 7YsIBb stI Y 3jsRY >d (nH IBtI Zt } RBts` sAs`s }s s %Bj% R stR}s t } B R$t 8BI$h{s RZ ? tI${ I P s{{$? Bt 8$ t sR B B $t% t s Zts }$t Z s } P { s8 t t s JZ sARB A BIs js jZ9 zstBR $t t BRU j } $8 B R ? s st $t%$R$Aj {B8B Zts ABjRs I }j? sR ${B sj R ZtIB R? BjB j PZt{$Bts ? s j $t% t B t j R}s{$B IBtI j PBtIB R t B eR s $I s I Zts }$t Z s JZ B ts $t%$R$Aj R st B s jBR BA` BR {B8B s jsR } RBtsR R t{Z t s s8A$? t t js } j? {Zjs 8 -${sts NBR $t%$R$Aj R >d EdH =tB I jBR } BAj 8sR 8? sR s% R JZ I A ? s sP Bt s Zt }B t{$sj YB8A $t%$R$Aj tB R ? s R? BjB js $t{B8} tR$? Bt I RZR {Bt ? t R R$tB RZ $t{s}s{$IsI }s s BA t $tPB 8s{$? Bt jZ8$tBRs *${YB I B s 8st s j YB8A $t%$R$Aj R ? s {$ B 7$ jBR B`BR PZ R t $t%$R$Aj R {B8B j R B I RZ {Z }B js jZ9 jBR s s% Rs ? s R$t P s{ s R ej B`B tB 8sj R {B8}B s {B8B Zts j t NsR I$P t R }s R {BtR $ Zk t R $ t t {B8B 8$R$? Bt P s{ s jBR skBR I jZ9 I 8st s JZ t js $ts JZ R {B8}B s {B8B j PB{B I js j t R BA t s js $8s t
© Los autores, 2001; © Edicions UPC, 2001.
d 1
* $t Bt s e$tR $t
3$ n d; =ts } $8${$sU jsR IBR Z ?t${sR PB B sP? sR {BtB{$IsR I j YB8A $t%$R$Aj } Z As $ PZ sAj I RZ -$R t{$s wy9JZ$ IsD ej YB8A $t%$R$Aj st R I RBj% ZtB I jBR $t{Bt% t$ t R JZ jj %s s}s `sIs RZ $t%$R$A$j$IsI j js{$BtsIB {Bt RZ { Z s w* {YsD ej 8$R8B YB8A $t%$R$Aj {BtR %s j R t $IB I js %$R s sj 8st t %$R$Aj R RZR $tsR *BR 8st{YsR }Zt Zsj R 8B%$? tIBR sj Zt? RBtB s Zts sj Z s I j RZ jB $ Zsj s js R s Z s I Zts } RBts {BtR $ Zk t Zts AZ t $tI${$B I js } R t{$s I j YB8A $t%$R$Aj
I jBR BA` BR I j - $B NBR skBR I jZ9 tB }BI ? st {Bt% t js $ts R$ tB -$R P s{{$? Bt Ns jZ9 s s% Rs ? s }Z R jBR B`BR I j YB8A $t%$R$Aj R$t t{Bt s t$t ? Zt BAR ? s{ZjB k {BtR {Z t 8 t tB R PB 8s ? s $8s t sj Zts s`B j s Zs k R$t sPsR I AZ{ B R s8BR t ZtsR {BtI${$Bt R }s {$IsR s jsR I tZ R B YB8A $t%$R$Aj 7 ? s8BR } ? s{ ${s8 t {$ BR R$ j B`B Z%$ R Zt ? tI${ I P s{{$? Bt $ Zsj sj I j s Zs 7$t 8As B sZtJZ jBR ? tI${ R I B t s YZ8B R %? B k s{ZBRBD RBt R$8$js R sj P s{{$? Bt I jsR I$P t R }s R I j B`B w{? I j s Zs R js } JZ K ts I$P t{$s {Bt j I j { $R sj$tB js JZ } 8$ js %$R$? Bt t I${YB 8 I$B yt{jZRB jsR } RBtsR 8$B} R }Z I t % 8 `B ks JZ jsR $8? s t R {s} sIsR }B j B`B R PB 8st I ? sR I js $ts k }Z I t {B8} tRs jBR I P { BR I Zt B`B 8$B} NBR B`BR I jBR } { R $ t t Zt { $R sj$tB 8Zk {Bt% -B }B jB JZ RZ ? tI${ I P s{{$? Bt R j 8skB I BIBR jBR I jBR st$8sj R {BtB{$IBR * tB R sR? jBR B`BR I tsIs j R R %$ ? st IsIs js stR}s t{$s I RZ 8 I$B ej YB8A $t%$R$Aj I A ? s sP Bt s s8A$? t B BR } BAj 8sR et js % R$? Bt 8BI ts I j 8$ B js } j? {Zjs 8B $sR I Zt YB8A $t%$R$Aj > 8B$ R BP st yt%$R$Aj st d 1H AsRsIs t js tB% js YB8? Bt$8s I <s k 3 7s$t >d M H R Zt YB8A I t B{$BR W${, <sjjBbsk JZ$ t R B ts $t%$R$Aj s {sZRs I Zt s{{$I t jsAB sj q sR RZ }$R s R ? s js ]yV t js PB 8s I Zt 8sj%sIB s t JZ JZ$ {s} Z s jB }s s RZR } B}$BR } B}? BR$ BR * R s{st t js {$t s ZtBR tB sAj R P { BR R} {$sj R JZ 8Z R st A$ t s jsR {js sR jBR } BAj 8sR JZ s{s s js $t%$R$A$j$IsI _B ` 8}jB {ZstIB j YB8A $t%$R$Aj PZ8s R j % t jBR }Zj8Bt R ej YB8A $t%$R$Aj I G jjR tB }BI? s {B8 t }? ZAj${B wI A$ tIB R{BtI R YsR s YsA I$ $IB jBR
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
d n
sj$8 t BRD t$ % R $ R w {B I 8BR JZ js $t%$R$A$j$IsI js sIJZ$ RZ {Z }B tB jBR % R $IBRD k? R tB }Z I t$ PZ8s gyt{Bt% t$ t R I js $t%$R$A$j$IsI 6 et j hj8 ;* st >d x H t 8BR B B 8? BIB s8A$? t {Bt Zts } tI$Is AsR {$ t ? h{s sZtJZ $ Zsj8 t Pst sR$BRB }s s sIJZ$ $ t R {sRB j }BI JZ $ t t jBR Pst sR8sR I s s% Rs jsR }s I R ej {$ t ? h{B i NstR$t $t% R $ s js 8st s I } t s t js 8s $s NBR -} $8 t BR tB Rsj t BIB jB A$ t JZ I A? s R} s k R j } B}$B {$ t ? h{B JZ$ t sIJZ$ j }BI AZR{sIB VZtJZ s {BR s I ZtBR $t% BR? 8$j R P { BR R {ZtIs $BRU {sIs % 9 JZ }sRs s s%? R I Zts } RBts ? R s t% ` { k 8Z k ? j R B ts 8? sR `B% t Ns } B R$%s $t{s}s{$IsI }s s %Bj% sj R sIB tB 8sj jj s YsR s j }Zt B I } B%B{s RZ I Rs}s ${$? Bt {ZstIB R Ysjjs t }j ts s{{$? Bt s s% RstIB Zts }s I ej {Z RB s Zt {Zs s I$8 tR$? Bt IBtI R t s ? s }s s I R}Z? R s}s { Ys{$ tIB {BRsR JZ t tZ R B 8ZtIB $I$8 tR$Btsj RBt $8}BR$Aj R R }Z R B s 8st s I {Bt% $ R t $t%$R$Aj V RsA$ tIsR I JZ jsR I$R st{$sR $t s ? B8${sR RBt st stI R JZ }BI 8BR {BtR$I s JZ js 8s $s B I$ts $s R ? s } ? s{ ${s8 t %s{? s ZtB }Z I } Zt s R 5}B JZ? t Bt{ R tB }BI 8BR s s% Rs jsR }s I R k 8Zjs s Pst sR8sR k R K tB R I js {Zs s I$8 tR$? Bt2 WBR jB $8}$I t jsR PZ 9sR I j$ sIZ s PZtIs8 t sj8 t I B $ t j? { ${B -$R t R t jBR s B8BR et js I j$ st } j? ? {Zjs NsR s% t Z sR I Z,s BB st9s$ >qY VI% t Z R BP Z,s BB st9s$ V{ BRR Y M Y *$8 tR$Bt d M;H j } B s Bt$R s {BtR Zk Zt sZ B8? B%$j 8Zk R} T {$sj {Bt j JZ sj{st9s % jB{$IsI R I 8? sR I d!((( ,8>Y k s{$sR sj {Zsj }Z I s s% Rs 8Bt sK tsR gR$t t { R$IsI I Z $j$9s t$t ? Zt ? Zt j ej $t% t B JZ Ys{ R B }BR$Aj I tB8$T tsIB I$ts8$9sIB I BR{$js{$? Bt RZ}Z R s8 t I$R8$tZk jsR PZ 9sR I tjs{ t j t? Z{j B k jBR j { Bt R I js 8s $s } 8$ $ tIB JZ j % Y? {ZjB }sR s s%? R I j R}s{$B %s{? B $tT s ? B8${B ej %$s` I A sj$9s R ? s}$Is8 t st R I JZ jBR s ? B8BR {Z} t RZ R sIB $t${$sj ej } B s Bt$R s Z{,s BB st9s$ R K tsjs {B { s8 t JZ jBR s ? B8BR R ? st R t{$sjT 8 t %s{? BR k JZ Zt t? Z{j B s ? B8${B ? }${B B{Z}s RBjs8 t Zts {Zs $jjBt? R$8s }s I j %BjZ8 t I j s ? B8B 7$t 8As B js $I s I R B $ $tsj I$R}BR$ $%B } R t s {$ BR } BAj T Bt 8Z Zs 8sR 7 ? Zt R tBR -}j${s } BIZ{ Ys{ R I j { Bt R k }BR$ Bt Rdn {Zks st$JZ$js{$? B $ $ts Zts I$R8$tZ{$? Bt I j sj{st{ I js PZ 9s j { B8s t? ${s JZ ` { j t? Z{j B RBA jBR j { Bt R I j s ? B8B * R sR? js t ? s j$A sIs t R sR {Bj$R$Bt R t }s ? {ZjsR RZj s ? s j sj }s s j {BtIZ{ B I j % Y? {ZjB * Y {YB -} $ t{$sR R$8$js R R sj$9st Zjs 8 t t jsAB s B $BR R} {$sj$9sIBR k A$ t } B $IBR {B8B jBR stI R s{ j sIB R I }s ? {ZjsR {Bt j ht I R ZI$s js ts Z sj 9s ? t $8s I js 8s $s _B B B jsIB sj I$R8$tZ$ js s s{{$? Bt j? { ${s JZ j t? Z{j B ` { RBA jBR j { Bt R ? R BR sAstIBts ? st RZR B ? A$ sR {$ {Zjs R R{s}stIB k } BIZ{$ tIB 8? sR sI$s{$? Bt j sj VR? JZ j } j$ B }s s j } B s Bt$R s
Ns 8s $s R ? s {B8}Z R s I s ? B8BR JZ }BR t Zt t? Z{j B {Bt {s s j? { ${s }BR$ $%s w{BtRT $ Z$IB }B } B Bt R k t Z Bt RD k j { Bt R I {s s j? { ${s t s $%s 8B%$? tIBR s RZ sj I IB t B A$ sR I 8$tsIsR ej s8sK ? tB ? }${B I Zt s ? B8B R I j B I t I d( d( 8 R$ tIB j s8sK tB I j t? Z{j B d; ? B8B Z%$ R j s8sK tB I Zt {s8}B I P? Z ABj j t? Z{j B R ? s Zts {st${s R$ ZsIs I d( 8 7$ Zt s t j { t B I j 8$R8B 8$ t sR JZ jBR j { Bt R R ? st 8$t? ZR{ZjBR stBR I s ts }ZjZjstIB }B jsR sIsR et {Bt sR js st $8s $s R ? s PB 8sIs }B s ? B8BR {Bt t? Z{j BR {s sIBR t s $%s8 t k j { Bt R {Bt {s s }BR$ $%s I tB8$tsIBR }BR$ Bt R ]ZstIB Zts }B {$? Bt I 8s $s R }Bt t {Bt s{ B {Bt B s I st $8s $s BIB j 8s $sj R {Bt%$ t t ? s sI$st
dn
© Los autores, 2001; © Edicions UPC, 2001.
d ;
* $t Bt s e$tR $t
3$ n dx ej * NstR$t 8 $ tIB I Zts }s I 5qsj % 9 js s s%$ Rs I {BR sIB }s s 8$t$8$9s js RZ} h{$ I {Bt s{ B2 ]s j }ZAj${$ s $B I js } j? {Zjs ;* st >d x H _B Ps%B }B s s{ $%s JZ }Z Is }s { j R R s YsA$j$IsI tB s t I } $ js
© Los autores, 2001; © Edicions UPC, 2001.
n * 7Z} 8st sj YB8A $t%$R$Aj U ? IBjBR {Bt }$ R I As B
d x
tB R ? s st B js } R t{$s I t $IsI R - s R R } B{ I t R I js B{ s%s I$8 tR$? Bt w j {Z RB s Zts {Zs s B JZ$t s I$8 tR$? Bt tB }s { RZh{$ t D {B8B }jst s j hj8 R$tB j 8? sR } BRs${B I jBR P { BR j sj R I j Y$}B ? ${B $t% t B V % { R jBR BA` BR tB I Rs}s { t }B JZ }sR t s Zts I$8 tR$? Bt }s sj js R$tB s {sZRs I js PB 8s{$? Bt I RZ $j R R Z{ Z sR P Z B I Zts sj$IsI {sIs % 9 8? sR {B8}j `s eR R j B $ $tsj }jst s8$ t B I js {$t s s t $ts >d EH et js %sR s I RZA ? st s I j 8 B ABts tR I Rs}s { R$t -}j${s{$? Bt Zt {Bt%Bk {Bt }sRs` BR k BIB Ns {js% js $ t Zt `B% t 8s 8? s ${B B}? BjB B }s s 8? sR R K tsR JZ$ t R ? s {s}s9 I I R{$P s j t$ 8s et I P t{$s }s s j j { B JZ s? Zt tB Ysks %$R$BtsIB j hj8 R? BjB s%st9s 8BR JZ js RBjZ{$? Bt d; et R %s ? Bt JZ I Rs}s { t I j 8$R8B $ t JZ % {Bt js {BtB{$Is RBR }sRs` BR JZ R ? st k tB R ? st sj ? Zt { ? ${B {$t 8s B ? sh{B Ys JZ $IB % Zts 8 ? sPB s I jBR I Rs}s {$IBR }Bj? ${BR Rs t PsR s s}s I js Y$R B $s JZ s%$ s RBA js {Bt{$ t{$s {Bj { $%s I j }Z AjB s t $tB
B A$ZR
{$t s I B A$ZR
Ns 8s $sj$9s{$? Bt I } Bk {{$Bt R 8 t sj R Is s8A$? t jZ s s { $s Z sR 8? sR B 8 tBR $t%$T R$Aj R } ? s{ ${s8 t $tI R Z{ $Aj R YsR s JZ tB I Rs}s { js 8 t JZ jsR { s VR? j I js } j? {Zjs R Zts { s{$? Bt 8 t sj I Zt RZA{BtR{$ t s B 8 t sIB {B8B j I j * B A$ZR ej {$ t ? h{B Z $j$9s jBR }BI R 8 t sj R sIJZ$ $IBR 8 I$st j ZRB I Zt I$R}BR$ $%B }s s js }B t{$s{$? Bt { A sj qs8A$? t >d M;H js ? }j${s P 8 t$ts I I A tP t s R {Bt Zts A R $s R$8$js t tI sIs }B js 8sj%sIs Y {Y${ s 7 j ts s{$sR s js }BR R$? Bt I j Zt - sK tB s $jZ $B JZ js RZ} Y B? ts I A {Z} s
8BtR ZB I yI
_jst s } BY$A$IB
7Z} 8st
7Z} $ j
!8 sY I Bt
6 ! B 8? BIB }s s {Bt% $ R t $t%$R$Aj {BtR$R t 8B% R st I } $Rs JZ j B`B JZ
tBR BAR %s tB t s $ 8}B I {s} s tsIs Ns % jB{$IsI I Zt RZ} Y? B {B8B 3jsRY j } 8$ I Rs 8s k I `s s Z I$IBR s jBR AstI$IBR st R I JZ R BR R I t {Z t s I jB JZ j R R ? s RZ{ I$ tIB et Zt }$RBI$B I js t sK tsAj R $ I j %$R$? Bt j } B s Bt$R s sIJZ$ R s YsA$j$IsI et s8ABR {sRBR j j R} { sIB BAR %s j P t? B8 tB I RI } R} { $%sR B}Z R sR et 3jsRY YsA$ Zsj8 t R 8Z R st jsR {BRsR sj {B8B RZ{ I t t tZ R B 8ZtIB tB 8sj V} tsR t 8BR $ 8}B I {s} s jsR s{{$Bt R I j Y? B R? BjB {Bt 8}js8BR jBR P { BRU Zt s 8s JZ }sRs I jsR 8stBR I j 8sj%sIB sj RZ jB { et F$8 G R jsR {BRsR RZ{ I t I RI j }Zt B I %$R s I j } B s Bt$R s !AR %s8BR sj R B I j 8ZtIB }s sj$9sIB 8$ t sR j } RBts` R I R}js9s {Bt tB 8sj$IsI G jjR $ t Zt I$% $IB js B >qY W b V{{ j s B d (nH IBtI -}j${s {? B8B Zts A A$Is Pst ? sR ${s } B}B {$Bts js }BR$A$j$IsI I sj s j R$R 8s t %$BRB I j $tI$%$IZB JZ js B8s I sj PB 8s JZ jBR R t $IBR } {$A t P t? B8 tBR I IZ s{$? Bt 8Zk A %
F$8 G R
ej tZ %B s{ j sIB
q sR R }sRB I jBR 8? BIBR JZ R Yst $I sIB }s s sj{st9s Zts R{Z $I$9s $t%$R$A$j$IsI k s 8BIB I Z ?j $8B {Z RB R? BjB tBR JZ Is R} s Zts R}Z R s s js } Zt sU "<B8A $t%$R$Aj 5 R ? sR sY? 2"
Ns {$t s I B A$ZR R Zts {BtR Z{{$? Bt B8? ${s JZ $ t js } B}$ IsI I JZ RZ RZ} h{$ - $B $t $B }Z I t {B R $tI ht$Is8 t R$t sAstIBts tZt{s j {Bt s{ B {Bt js 8$R8s _Z I {BtR Z$ R P? s{$j8 t {Bt Zts $ s I }s} j Zt$Is sR Zt $ B }B RZR - 8BR
d;
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
d
;
57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
7BA jBR I j$ $BR I Zt RsA$B jB{B j RZ K tB I js $t8B sj$IsI B `Z stIB s R *$BR {Bt j { Bt R k } B Bt R
s{ JZ? s js 8 Rs {s sPsj{B k {s? I A Z{ R RBA RZ RZ} h{$ z$A sAs sj I IB js P sR JZ 8$ }sI YsA? s R{ $ B I As`B I 8$ YB ? BR{B}B {Bt RZ j s $tRBj t s $R B{ ? s ${sU "NBR 8BtR ZBR tB 8Z t" 7? 8Z tU jBR 8BtR ZBR 8Z t s8A$? t BIBR 8B $T 8BR js $t8B sj$IsI u8 jB Ys {BthsIB 8$ sAZ jB j {s I tsj t RZ s Bt? su R js %BjZt sI I *$BR js Z ?t${s Zt I? s 8B $ ? st jBR 8BtT R ZBR I }$ I s $ $IBR }B 8$ B ZjjB stZ j ? Z`${s N? s$t 9 B8s 9B >d E1H
V I ? } B jjB tB R B s {BRs JZ Zt Y {YB Os R Z$ 8BR I$RT {Z $ tIB t js t$IsI $ Z j 7 % st jBR `Z { R JZ jB YsA? st {BtI tsIB s js YB Z s
wy9JZ$ IsD ej 8BtR ZB I 3 st, tR $t }s sI$ 8s I jsR $t% t{$Bt R I j R YZ8stB JZ s{sAst }B IB8$ts s RZ } B}$B { sIB z? { B 3 st, tR $t R? 8ABjB I js {$ t{$s RZ K ts {Bt 8 `B s j 8ZtIB sZtJZ R? BjB {BtR$ Z {Bt% $ jB t Zt R$ $B } B sj j$A s s RZ { $s Z s * js } j? {Zjs 3 st, tR $t I s k 7Y jj k > s k 7Y jj k:R 3 st, tR $t d ;H
© Los autores, 2001; © Edicions UPC, 2001.
d M
* $t Bt s e$tR $t
Ns BR{Z $IsI $t%sI BIBR jBR $t{Bt R I j % ZR B k I {sI t jsAB s B $B =ts {B $ts I R$j t{$B }s { YsA {ZA$ B js R st{$s qBIB R JZ$ ZI 5qBIB2 =ts R$t$ R s h Z s R I Rj$9s {Bt s $j$IsI }B t B sR {BtI tRsIB R k - sK tBR s}s s BR st$}Zjs }sjst{sR B} $8 AB Bt R 8 9{js I R{BtB{$IBR } BIZ{ BR eR ? s s }Zt B I {Zj8$ts j sAs`B I sK tBR sR $tP Z{ ZBRBR RPZ 9BR Vj ht js I$sA? Bj${s $t% t{$? Bt P Z B I RZ 8 t tP 8$9s R ? s s }Zt B I 8s $sj$9s R VYB s }$ tRs t %B9 sj s j R I %Bj% ? s BIB j BI$B s{Z8ZjsIB _s s ? st }B YsA R 8BPsIB I RZR $I sR Ns YZ8st$IsI }BI? s 8} 9s s 8Ajs O I } t 7 t{$ tI t jsR jZ{ R ej R$j t{$B R {Bt%$ t Zts sj s sA? s I 8$j I 8Bt$BR V {$st jBR R$jA$IBR ej }? ZAj${B $ s $tRZj s et js 8$t? ZR{Zjs Rsjs IBtI R t{Z t s j } Bk { B {$t 8s B ? sh{B R Bk -{js8s s Zt RZIB BRB B} s $BU "g sjI$ s R s ks %Bj% 8BR s R s 7$ R JZ R B I js j { ${$IsI tB }Z I R AZ tB <Bk R Zt PZR$Aj 8sK tsts js j? s8}s s I j } Bk { B O {ZstIB tB js {BtRsA$Is R ${{$? Bt gVR? tB Ysk 8st s I } Bk { s Zts } j? {Zjs t {BtI${$Bt R " 7Z j s $AZ$ R sj $ B qsj R I $j B JZ %$%$? B Ys{$s j R$ jB zyy s ] j I R{ZA $8$ t B tB _ R s R 8} stB I Zts PZ 9s I s s{{$? Bt BA t$Is sj P B s j s ?8As @ {Bt Zt }sK I R{ZA $8$ t B I j P t? B8 tB I js j { $9s{$? Bt }B P B s{$? Bt jBR -} $8 t sIB R I I${sIBR s P B s jBR 8? sR %s $B}$t BR BA` BR IZ st jBR R$ jBR }BR $B R tB jj s Bt s $t Z$ js $8}B T st{$s k js ts Z sj 9s I jB JZ t? st t 8stBR WB R ? s YsR s j R$ jB zyy ks I tZ R s s JZ js j { ${$IsI k j 8s t $R8B 8} 9s ? st s {BtR$I s R As`B Zt }Zt B I %$R s 8? sR $ Z BRB k R }sRs ? s I js 8 s BAR %s{$? Bt I jBR P t? B8 tBR ts Z sj R {B8B j skB B js }$ I s $8? st s RZ R ZI$B {Bt Zt {$ B $ B G$jj$s8 p$jA ]Ys j R t`s8$t 3 st,j$t ]Ys j R VZ ZR I ]BZjB8A <stR ]Y $R $st ! R I VtI ? s $ V8}r ${Ys j 3s sIsk FBR }Y < t k qYB8sR Vj%s eI$RBt Fs8 R ]j , s-b jj t 8Z{YBR B BR tB st sPB ZtsIBR t RZR I R{ZA $8$ t BR Yst j %st sIB j I$h{$B I j {BtB{$8$ t B I R s $t s{{$? Bt PZtIs8 t sj I js ts Z sj 9s JZ YBk I tB8$ts8BR j { B8s t $R8B k RBt jBR R}BtRsAj R I js } R t{$s I js 8$R8s t tZ R s %$Is {B $I$sts V js }s JZ j P? R${B A $ ? st${B Fs8 R ]j , s-b jj wdMndTdM D R sAj {? s Zts $ Z BRs B ? s j { B8s t? ${s R I Rs BjjsAst jsR s}j${s{$Bt R } ? s{ ${sR I js j { ${$IsI k j 8s t $R8B et dMMd NBtI R R Zts I jsR } $8 sR {$ZIsI R I j 8ZtIB JZ {Z t s {Bt sjZ8A sIB }? ZAj${B wjs } $8 s {$ZIsI {Bt sjZ8A sIB }? ZAj${B B sjT 8 t j { $h{sIB PZ V, Btt t !Y$B eR sIBR =t$IBRD p$ Bts t dMME R ? s js R ZtIs {$ZIsI Z B} s t {BtR Z$ jB Ns t ? s j? { ${s {Bt RZR Ps{$j$IsI R }s s js } BIZ{{$? Bt j stR}B k j {BtRZ8B R }B}Zjs $9s k R %$R s {B8B Zt 8 I$B }s s 8 `B s j t$% j I %$Is et j } $8 {Zs B I tZ R B R$ jB R I Rs Bjjst jBR }B}Zjs R j { BIB8? R ${BR k 8}$ 9s s `Z s Zt st }s} j js }ZAj${$IsI JZ $t{$ s sj {BtRZ8B ]B8B R K tsjs j } BP RB NZ$R s ? t 9 s $BR t RZ s8 ts <$R B $s I jsR 8? sJZ$tsR j? { ${sR >d xH j RZ K tB I j YB8A I j R$ jB y I %$%$ 8 `B R {Bt%$ t j R$ jB t Zts {Zj Z s I j {BtRZ8$R8B eR R}? $ Z tT R} st9sIB }B jsR }BR$A$j$IsI R t %$R sR k } R$8$R s }B jBR }BR$Aj R $ R BR JZ BIB P t? B8 tB tB I j BIB {BtB{$IB t sK ts JZ Is ? s }jsR8sIB t Zt 8 I$B JZ s8A$? t ts{ ? ss htsj R I j R$ jB }sRsIB k JZ I A s8A$? t 8Z{YB s js j { ${$IsIU j {$t Ns }sjsA s j { ${$IsI $ t RZ B $ t t js }sjsA s $ s j , Bt tB8A {Bt JZ R I R$ ts sj s ?8As ej B $ t I js }sjsA s 8s t $R8B R s8A$? t $ BU } B%$ t I s t R$s $? Bt I js s{ Zsj qZ JZ? s IBtI jBR st $ ZBR $ BR Ysjjs Bt }$ I sR $8? st Ys{ 8? sR I 1 ((( sK tBR @
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
d
3$ ; d et js R ZtIs 8$ sI I j R$ jB zyyy js j { ${$IsI {BtR$I sIs {B8B R} { ? s{ZjB jj s s jsR P $sR }B}Zjs R k s jBR j st R RsjBt R I js s $R B{ s{$s et R `Z B t j JZ }s ${$}s I AZ t sIB js {B P st{ Rs j `B% t JZ } tI I j {YB t Zts }js sPB 8s R {s sIB j { BR ? s ${s8 t 8 I$st Zts 8? sJZ$ts j? { ${s I P B s8$ t B NsR } RBtsR JZ j BI st jB {B8} Z Ast Ys{$ tIB Rsj s Zts {Y$R}s I RZ ts $9 sj Bt wYB8A I js $9JZ$ IsD s{ {s j Zt I IB w8Z` I js I {YsD B I RZ {sA 9s sj s} B-$8s j Zt AsR ? ej 8$R8B `B% t s s {Bt RZ 8stB $9JZ$ Is B{$ BR I }s} j }Z R BR RBA j } A B eR R} { s{Zjs -} $8 t B B `Z B I Rsj? Bt tB R ? s I 8sR$sIB sj `sIB I jBR -} $8 t BR j { BR ? s ${BR YsA$ Zsj R t jBR 8ZR BR I js {$ t{$s I BIB j 8ZtIB
© Los autores, 2001; © Edicions UPC, 2001.
dM(
* $t Bt s e$tR $t
Ns j { ${$IsI k j 8s t $R8B {BtR $ Zk t js AsR I jsR j {B8Zt${s{$Bt R I jBR j {T BIB8? R ${BR k t t sj I js {tBjB ? s s{ Zsj VZtJZ RZR s}j${s{$Bt R RBt 8Z{YsR k RZ ZRB {B $I$stB RZj s I$P? {$j }s s Zt tB R} {$sj$R s {B8} tI js ts Z sj 9s P? R${s I R BR P t? B8 tBR WB I A - sK ts }Z R JZ t ? }B{sR st $B R R sRB{$sR t s P t? B8 tBR - sK tBR w sj%st$R8B 8 R8 $R8B D k JZ tB PZ R YsR s htsj R I j R$ jB }sRsIB JZ R R t sR t jsR AsR R I RZ PZtIs8 t s{$? Bt P? R${s ej {BtB{$IB hj? BRBPB k 8s 8? s ${B A $ ? st${B stI iZRR jj wdM 1Td (D R{ $A? s t d 1nU ">Ns j { ${$IsIH R Zts PB 8s I {B8}B s R jsR {BRsR Vj I {$ {? B8B R {B8}B st jsR {BRsR j { $9sIsR k t JZ? {$ {ZtR st{$sR jB Yst R$IB Y 8BR I${YB BIB jB JZ }BI 8BR I {$ ]ZstIB I$ B JZ Zt j { ? Bt $ t Zts {$ s {st $IsI I j { ${$IsI t s $%s IBk s t tI R$8}j 8 t JZ R {B8}B s I {$ B 8BIB Ns j { ${$IsI tB R {B8B js }$t Z s B`s Zts RZR st{$s JZ }Z Is {BjB{s R RBA j j { ? Bt k JZ$ s R I tZ %B R$tB 8 s8 t Zt tB8A {Bt% t$ t }s s {$ sR j k R P? R${sR " et s9? Bt I RZ {B8}j `$IsI js j { ${$IsI k j 8s t $R8B Yst {BtR $ Z$IB Zts R} {$ I {s`? Bt I RsR sj JZ {Z $ {ZstIB R AZR{s Zts -}j${s{$? Bt {Bt%$t{ t B Zts ` s I 8$t$R{ t{$sR {$ t ? h{sR t JZ PZtIs8 t s jsR { s{$Bt R I js {$ t{$s h{{$? Bt q tB sABtsIB }s s j I R%s ? B k js Pst sR? s I RAB IsIs qsj % 9 YBk t I? s R }s} j Yst }sRsIB s I R 8} K ts jB B sR }s R I js P? R${s R${s {Z? st ${sD I jBR P { BR I {B8B js P? R${s JZ R B{Z}s I j {B8}B s8$ t B RZAs ? B8${B wP? % jB{$IsI R { {stsR s js I js jZ9 w js $%$IsI R} {$sjD B I jBR {s8}BR s%$ s B $BR $t tRBR w js $%$IsI t sjD ; d 3st sR? sR j? { ${sR k 8s t? ${sR
V } $t{$}$BR I R$ jB js }B}Zjs $9s{$? Bt I j ZRB k s}j${s{$Bt R I js t ? s j? { ${s B $ $ts ? s Zts R $ I } j? {ZjsR t jsR JZ js j { ${$IsI s js } B s Bt$R s !A sR JZ sZ B R {B8B FB I$ ]BR s t RZ BA s 5<sk sj Z$ t sY? PZ s2 =ts Y$R B $s I j {$t I {$ t{$s h{{$? Bt >d H Yst t jBAsIB As`B j ? ZjB t? ${B I "Pst sR? sR j? { ${sR" qY ej { ${$ k ]Z R ? s js } $8 s s js JZ R Z$ ? st B sR I ? ZjBR Ys B jB{Z t R {B8BU qY ej { ${$ k pBBR >d (xH N$JZ$I ej { ${$ k >d ( H qY ej { ${ 7 %st >d ( H qY ej { ${ _Bj${ 8st >d ( H ej { ${ q stRPB 8s $Bt >d ( H ej { ${$ k PB W %BZRt RR >d ( H qY ej { ${ z$ sj$R >d d(H qY ej { ${ ytRBj R >d d(H ej { ${ BB R >d ddH qY ej { ${ N >d d1H Ns ] $t Z ej { $JZ >d ( H B qY ej { ${ <Z8} >d d;H t{$? Bt R} {$sj I t B I R Z}B 8 { js {$t s ej YB j j? { ${B >d (MH I j Z Bj tR 7 ZtIB I ]YB8? Bt wdM dTd 1 D ZtB I jBR }$Bt BR I j ? t B `Zt B sj P st{? R p B R ? j$r R wdMEdTd nMD Ns } j? {Zjs -}jB s jsR $t8 tRsR }BR$A$j$T IsI R I js sZ B8s $9s{$? Bt I jBR R %${$BR IB8? R ${BR I Zt YB j I j PZ Z B t RZ % $ t {? B8${s 7 ts s js Y$R B $s I IBR Z $R sR NsZ s k ? st JZ R sjB`st t Zt YB j IBtI j R %${$B YZ8stB Ys R$IB RZR $ Z$IB }B 8? sJZ$tsR JZ PZt{$Btst {Bt t ? s j? { ${s NsR 8sj sR R sA t }B R? RBjsR k RZ {Bt t$IB I {s8$RsR k }sK tZ jBR R {BjB{s sZ B8? s ${s8 t t {s`Bt R JZ R sA t k {$ st =t { }$jjB jZR s jsR AB sR I j } B s Bt$R s 8$ t sR JZ B B } $ts R$t JZ tsI$ jBR 8st ` ? st R t`sABtsIB k sP $ sIB }B Z tR$j$BR {Bt s}s t %$Is } B}$s ]ZstIB j t{s sIB I js 8sJZ$ts $s R 8AB s{Ys k {Bt { s k I R{Bt { s jBR 8stIBR R$t Bt t$ RBt jBR s Ps{ BR I j YB j 8}$ 9st s PZt{$Bts I Zts 8st s I T R{BB I$tsIs NBR hj8 R qY <sZt I <B j >d ( H k qY ej { ${ z$jjs >d ddH $t{$I$ ? st t j 8$R8B 8s $tR}$ ? stIBR t R s BA s et j } $8 B js PZ 9s %$ sj R}BtRsAj I js st$T
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
dMd
8s{$? Bt I jBR BA` BR $ t Zt B $ t RBA ts Z sj tB j? { ${B et j R ZtIB jBR BA` BR $tst$8sIBR I Zts {sRs {BA st %$Is wZt }BjjB sRsIB Zts sjPB8A s JZ R B ts R }$ t D }s s I R 8As s9s R I Zt YZ? R} I tB I R sIB ! s I jsR R s8A? B ${sR s}j${s{$Bt R I js j { ${$IsI R ? s } B}Z R s t qY ej { ${ etjs >d ( H Zts I jsR IBR } j? {ZjsR I js R $ } B s Bt$9sIs }B j } BP RB _ZII tY sI RBR? sR I j $t PsAj } BP RB 3 st9 I ]B} tYs Z Ps8BRB }B jBR $t% t BR JZ I R{ $A? s t jsR t sK tsAj R }? s $tsR I j q ! NBR $t% t BR I R }B{B sPB ZtsIB } BP RB {s t YsA$ Zsj8 t t 8stBR $t -} sR k s{sAst R$ 8} {sZRstIB 8? Zj $}j R R B}${$BR VJZ? j $t% t B t {Z R $? Bt R Zts 8s s%$jjBRs %s $ s 8? s ${s j? { ${s {s}s9 I sZ8 t s s %BjZt sI j s8sK tB I {ZsjJZ$ BA` B } RBts B st$8sj $t{jZ$IBR V T $jZ $B tB 8 tBR { ? Aj JZ B BR {Z RBR 8}j sIBR t js h{{$? Bt }s s j sZ8 t B I s8sK tB w]s}? ZjB dD et psj%st${ 3jZ$I >d (MH R {Z js I j hj8 N$JZ$I ej { ${$ k j } BP RB Gs R j t{s sIB I } B}Bt B B RB } tI t ZRB I js j { ${$IsI et R {sRB } 8$ $ j %Z jB I {ZsjJZ$ BA` B RBA j JZ R s}j${s NBR } BAj 8sR R } R t st {ZstIB j 8$t t j tB }s s RZR $tPB ZtsIsR {$ t ? h{B s}j${s RZ $t% t B s jsR } RBtsR {Bt tB sAj ? -$ B w}s s ? %? { $8sRD qY ej { ${ z$ sj$R $t BIZ{ j 8s I j } BP RB JZ Z $j$9s I R{s sR j? { ${sR }s s RZ{$ s t R {sRB st$8sj R 8Z BR =t tB sAj } { I t I j hj8 ej IB{ B 3 st, tR $t >3 st, tR $t d ndH AsRsIB t js Ps8BRs tB% js I s k 7Y jj k 3 st, tR $t B j 8BI tB _ B8 B >3 st, tR $tU B Y BI t _ B8 ZR dMdMH RBA j JZ %Bj% 8BR 8? sR sI jst VZtJZ t t? Z8 B $tP $B t {B8}s s{$? Bt {Bt R sR } $8$ $%sR } j? {ZjsR JZ -}jB sAst jsR }BR$A$j$IsI R I js j { ${$IsI s8A$? t t jBR B ? t R I j {$t s}s { t } j? {ZjsR JZ $8s $tst ZRBR tB 8 tBR I j$ st R I j 8s t $R8B GB , sI esRk >d ( H k Ns ]Z$R$t s t $JZ >d ( H I js s}s P st{ Rs I 7 ZtIB I ]YB8? Bt {BtR $ Zk t {js BR ` 8}jBR et qY s T t ${ 7JZ$ >d ( H Zt 4Z$IB 8s t? ${B Ys{ }BR$Aj JZ Zt }s sj? ${B {s8$t Zts { R s {BA Zt %$Is k Zts } RBts R {B8}B I Zts PB 8s $I? {Zjs wg{BRs }s s js JZ tB R JZ$ t$t ? 4Z$IB 8s t? ${B D Ns $I s I Zt I$R}BR$ $%B {s}s9 I s s st B BA` BR 8 ? sj${BR {B8B $t{sZ sR } RBtsR s}s { t qY GBtI PZj ej { BT s t >d ( H k qY s t ${ =8A jjs >d ddH et j s ?8A$ B j$ s $B } IB8$ts t R BR } $8 BR $ 8}BR js %$R$? Bt I js j { ${$IsI k I j 8s t $R8B {B8B PZ 9sR I st$8s{$? Bt {sR$ 8? s ${sR eR j {sRB I qY NBR V8$ BR 3$sR{B >dM 1H I V YZ ]Btst *Bkj B I qY ]B8$t is{ >dM dH I NB I Nk Bt IBtI s}s { j ${s I t ? s I Z $j$IsI Zt$% Rsj }Z R R$ % {B8B {B8AZR $Aj % $j Zts PB 8s j { B8s t? }s s jsR 8? sJZ$tsR %Bjst R k jBR sZ ? B8s sR k Ys{ }BR$Aj $t{jZRB js j }s ? s eR sR } $8 sR BA sR {BtR $ Zk t Zt h j 4 `B I jsR -} { s $%sR R} st9sR k { jBR JZ s{B8}sK tst R$ 8} s {ZsjJZ$ s%st{ {tBj? B ${B et jjsR js j { ${$IsI sj $ Zsj JZ j 8s t $R8B R %$R s {B8B Zts RZ I PZ 9s B sj$ t B %$ sj {s}s9 I IB s I %$Is s jB $tst$8sIB {B8B Zt }BI BRB %$ B $9st B {B8B Zt $tR Z8 t B I {Z s{$? Bt sZtJZ R$ 8} k t R} {$sj t jsR } j? {ZjsR As`B Zts B ?} ${s YZ8B ? R ${s B AZ j R{s Ns P % R{ t{$s I $ttB%s{$Bt R {tBj? B ${sR t j {s8A$B I R$ jB JZ YsA ? s } B}${$sIB R sjZI I $t tZsR Pst sR? sR PB 9s ? s sR RZ ej B% $j } }s sIB I {sjIB I {s t {Bt{ t sIB B $ $ts $B I yt js s Z $j$9sIB {B8B {B8}j 8 t B sj$8 t ${$B t 8Z{YBR YB s R R}sK tBj R t jBR sK tBR R R t s B8s RZ tB8A I R s RZR st{$s
© Los autores, 2001; © Edicions UPC, 2001.
dM1
* $t Bt s e$tR $t
3$ ; 1 NsZ s js RB } tI$Is YZ? R} I I ej YB j j? { ${B >d (MH st Zt { }$jjB sZ B8s $9sIB JZ }s { YsA {BA sIB %$Is } B}$s {BtRBj$Is{$? Bt t js %$Is {B $I$sts w$jZ8$ts{$? Bt j? { ${s j { BIB8? R ${BRD s jBR R{ $ B R k Z$Bt$R sR I {$ t{$s h{{$? Bt s B $ t s RZ $8s $ts{$? Bt Ys{$s $ B $BR 8 tBR -}jB sIBR B }B jB 8 tBR s PZtIs8 t s RZR { s{$Bt R
; 1
ej 8BtR ZB I 3 st, tR $t k js j { BA$BjB ? s
=tB I jBR ? B}${BR {Z t R t js j$ s Z s Pst ? sR ${s I BIBR jBR $ 8}BR Ys R$IB j I j B tB I jBR 8Z BR s js %$Is eR {Bt{ } B I R$? Bt I RI js 8Z R Ys $t } sIB {B8B Zts 8st$P R s{$? Bt I jBR 8$ IBR $t $B R I j YB8A s 8B $ k I Rs}s { U 8sZRBj BR }$ ? s8$I R k B sR {BtR Z{{$Bt R PZt s $sR RBt Zts 8Z R s I jBR $t t BR I js YZ8st$IsI }B sP Bt s R s $I s BAR R$%s Ns Pst sR? s Ys sAB IsIB j 8s I js RZ {{$? Bt I jBR 8Z BR Z $j$9stIB }? B{$8sR Z B sR { sR 8? s ${sR - t sR I Zts AZ ts IBR$R I { I$A$j$IsI =tB I jBR } $8 BR P t R {j? sR${BR JZ $t t s IB s I Zts {$ s AsR {$ t ? h{s js A? ZRJZ Is I js PZ t I js %$Is jB t{Bt s8BR t 3 st, tR $t B j 8BI tB _ B8 B I js R{ $ B s $t j Rs s k 7Y jj k 7Z BA s {BtR $ Zk Zt }Zt B I $t4 -$? Bt t jsR ts s{$Bt R I js ? }B{s k R ? Zt sj ZtBR R} {$sj$RT sR I j s ?8A$ B I js {$ t{$s h{{$? Bt {B8B j R{ $ B $t j? R $st G VjI$RR 8s {s j ts{$8$ t B
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
dMn
I R ? t B j$ s $B ej 8BtR ZB I 3 st, tR $t PZ j P Z B I Zt t{Z t B s{s {$IB t p$t A s IZ st j % stB I j sK tB dMdE t j JZ }s ${$}s Bt R{ $ B R {B8B jB I k Bt k _ {k 7Y jj k k s8A$? t Zt 8? I${B j IB{ B _Bj$IB $ qsj {B8B js } B}$s s k 7Y jj k -}j${s t js $t BIZ{{$? Bt I js I${$? Bt I j 3 st, tR $t I dMnd t R s Zt$? Bt R YsAj? B I js PZ t I js %$Is k I js }BR$A$j$IsI I st$8s Zt {sI? s% NBR PsR{$tst R -} $8 t BR BjB B $ sj$stB PZ Bt I$R{Z $IBR Rs tB{Y psj%st$ s I NZ$ $ psj%st$ wd n Td MD Zt hR$? } BP RB I sts B8? s t js =t$% R$IsI I BjBt$s t sJZ jjs ? }B{s I P % R{ t{$s }B j ZRB k jsR s}j${s{$Bt R I js j { ${$IsI R} {$sj8 t t jB B{st s jsR 8? sJZ$tsR j? { ${sR ej hR$? BjB B tB ? B JZ R$ R s}j${sAs Zts {B $ t j? { ${s s Zts st{s I sts ? R s R 8B%? s {Bt%ZjR$%s8 t 5e s js j { ${$IsI j R { B I js %$Is2 et Zts {? j A -} $ t{$s P {YsIs j 1( I R } $ 8A I d ME t RZ I$s $B I jsAB s B $B psj%st$ {BtR$ Z$? B Zt 8B%$8$ t B s} T {$sAj I j st{s I Zts sts sj }Bt js t {Bt s{ B {Bt IBR 8 sj R I$P t R {BA k Y$ B wP t? B8 tB {BtB{$IB s{ Zsj8 t {Bt j tB8A I j { ${$IsI sj%? st${sD eR s -} $ t{$s }Bt? s I 8st$h R B js 8 I$s{$? Bt I js j { ${$IsI 5} B I I? BtI } B% t? s ? R s2 5* jBR 8 sj R B I j `$IB st$8sj2 ]B8B sts B8$R s B} ? B }B sRB{$s js s ? R Z ?j $8B k sh 8? B JZ YsA? s I R{ZA$ B js I tB8$tsIs j { ${$IsI st$8sj n _s { R JZ _Bj$IB $ JZ R YsA? s sIZsIB t Zt } R $ $BRB { t B I 8 I${$ts I eI$8T AZ B js ? B s8A$? t jB JZ RsA? s RBA jBR sAs`BR I p$B%stt$ VjI$t$ t$ B I psj%st$ JZ YsA? s s8}j$sIB jBR R ZI$BR I sj%st$9s{$? Bt {Bt BIs Zts R $ I B ? stBR I st$8sj R 8Z BR {Bt $I? t ${BR RZj sIBR ej sK tB dM(n VjI$t$ {BtR$ Z$? B j } 8$RB }s s j { $h{s j {sI? s% I Zt sR R$tB s`ZR ${$sIB t js YB {s t js } $R$? Bt I W b s t NBtI R ej sK tB R$ Z$ t t Zt -} $8 t B R$8$js Zt sR$R t -}j${? B JZ j {sI? s% g}s {? s j %s R }B R? 8$R8B k s} s RZR }ZK tBR Ns -{$ s{$? Bt } BIZ{$Is }B R sR tB ${$sR $8}ZjR? B s s k 7Y jj k s R{ $A$ RZ js B ? B ${B RBA 3 st, tR $t IBtI j BAR R$%B IB{ B z? { B 3 st, tR $t sts B8$R s {B8B psj%st$ $tPZtI? s %$Is tB s Zt `$IB 8ZR{Zjs R$tB s Zt {Z }B {B8}j B I Zts PB 8s } 8st t t % 9 I stR$ B $s et js tB% js 3 st, tR $t I R t{sI tsIB >3 st, tR $t ZjB t d (D j } B}$B $st G VjI$RR =tABZtI d nH wsIs} sIs sj {$t {Bt j 8$R8B ? { s R BR s{Bt {$8$ t BR Y$R ? B ${BR =t I Rj$9s8$ t B R}s{$BT 8}B sj R$ % I -{ZRs }s s t%$s s FBR }Y BI tjstI }Bj? ${B $ sIB I j sK tB 1(1( s js p$t A s I dMdE Vjj? {B$t{$I$ ? s {Bt } RBts` R sj R {B8B 7Y jj k k k Bt k {Bt B BR h{ ${$BR {B8B j 8$R8? R$8B z? { B 3 st, tR $t k RZ 8BtR ZBRs { s{$? Bt <sA? st -$R $IB B BR $t t BR } %$BR k {B ? st BR I %$%$ {sI? s% R B I { s %$Is AsRsIBR t 8$ BR B j k tIsR IBtI $8} sAs js $I s I JZ js PZ t I js %$Is s sj B 8? s ${B B RBA ts Z sj =ts j k tIs `ZI? s I j R$ jB zy YsAjsAs I j pBj 8 Zt {Z $BRB YB8A s $h{$sj I As B { sIB 8 I$st s R {sAsj? R ${sR }B j sA$tB N[ Bb t _ s s k JZ sIJZ$ ? s %$Is {ZstIB j sA$tB s ZsAs t RZ P t js }sjsA s "e8 " JZ R$ t$h{s % IsI Ns I R Z{{$? Bt I js { $s Z s R {BtR Z? s sj AB s js j s $t${$sj }Z R B JZ js }sjsA s "8 " R$ t$h{s "8Z B" ej R{ $ B sZR ? s{B pZR s% k $t, tB% js ? s R s j k tIs t ej pBj 8 >*
VK tBR I R}Z? R j P? R${B $ sj$stB Vj RRstI B zBj s wd ;xTdM1 D I 8BR s ? s RZ B k I$R K ts ? s j } $8 t sIB j? { ${B B }$js w}$js I zBj sD IsIB s {BtB{ j sK tB dM(( {BtR Z$IB {Bt I$R{BR ? R s R js AsR I Y$ B k {$t{ sj tsIBR R }s sIBR {Bt Zt s}B $8} tsIB I Zts RBjZ{$? Bt Rsj$ts e I jsR 8BI tsR As ? sR j? { ${sR n
© Los autores, 2001; © Edicions UPC, 2001.
dM;
*Â&#x201A; Â&#x20AC;$t Â&#x20AC;Bt s e$tR Â&#x201A;$t
3$ ; n et Â&#x201E;Â&#x201A; jBR 8ZÂ&#x201E;BR IÂ&#x201A; js 8stR$? Bt IÂ&#x201A;j IB{ BÂ&#x201E; z? { BÂ&#x201E; 3Â&#x201E;st,Â&#x201A;tR Â&#x201A;$t Zts }s ? Â&#x201A; ${s Â&#x201A; $t{B8}Â&#x201E;Â&#x201A;tI$Is {Â&#x201E;$s ZÂ&#x201E;s RÂ&#x201A; B{Zj s IÂ&#x201A; js 8sjIsI IÂ&#x201A; jBR YB8AÂ&#x201E;Â&#x201A;R *Â&#x201A; js }Â&#x201A;j? {Zjs ej IB{ BÂ&#x201E; 3Â&#x201E;st,Â&#x201A;tR Â&#x201A;$t >3Â&#x201E;st,Â&#x201A;tR Â&#x201A;$t d ndH
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
dMx
pBj 8 d dxH Ns % R$? Bt {$t 8s B ? sh{s 8? sR {BtB{$Is h j s js j k tIs B $ $tsj Is s I d 1( wej pBj 8 >* pBj 8 d 1(HD =ts %$R$? Bt 8BI t$9sIs I j 8$ B js t{Bt s8BR t j hj8 ? B}Bj$R > B}Bj$R d 1EH IBtI j {$ t ? h{B iB bst R {s}s9 I { s Zt BAB I s}s $ t{$s YZ8sts Z $j$9stIB ? {t${sR AsRsIsR t js j { ${$IsI ! s BA s ? R s $tR}$ sIs j `sts8 t t j 3 st, tR $t I s k 7Y jj k R js } j? {Zjs <B8Zt,ZjZR I 3[ ZY >d dEH ]Bt Zts %$R$? Bt } 8Bt$ B $s I jB JZ sj ZtBR sK tBR 8? sR s I s{Bt { ? s t Vj 8st$s {Bt j sR{ tRB k {s? Is I <$ j R ts s js { s{$? Bt }B }s I Zt sj IB{ B <stR t I Zt YB8A s $h{$sj I }BI BRs $t j$ t{$s sZtJZ {s t I sj8s 7Z sP? st }B % t s R I jBR YZ8stBR JZ j Yst IsIB Zts -$R t{$s 8$R sAj j jj %s s {Bt% $ R t Zt I${ sIB I R t{sI tstIB t RZ I j$ $B Zts Z s 8ZtI$sj Ns $t % t{$? Bt I$%$ts {ZstIB RZ 8sjIsI Ys jj sIB I 8sR$sIB j `BR }Bt ht s RZ -$R t{$sU Zt skB t%$sIB }B jBR I$BR R {s ABt$9s sj R {ZstIB ? R BRs AjsRP 8s t RZ {Bt s ej P { B I Zts {B $ t j? { ${s RBA Zt R %$%B R I {$ j 8B%$8$ t B I jBR j { Bt R j$A R t jBR 8s $sj R {BtIZ{ B R R sj B A$ t {BtB{$IB YBk t I? s et {ZsjJZ$ 8st$}T Zjs{$? Bt I JZ$}BR j? { ${BR R s8BR RB8 $IBR sj $ R B I j { B{Z{$? Bt * Y {YB Zts {B $ t j? { ${s js $%s8 t } JZ K ts }Z I } B%B{s j R$Bt R s% R t Zts } RBts B $tT ? R {jZRB B{sR$Bts RZ 8Z e-$R Zt j? 8$ $tP $B }s s I { s j }sRB I js {B $ t e ; R R$ ? Zs sj I IB I Zts 8$j? R$8s I s8} $B ej }sRB I {B $ t {Bt $tZs } BIZ{ {sj tT s8$ t B 8$ t sR JZ js {B $ t sj ts R 8st$h R s 8 I$st Zts R tRs{$? Bt I YB 8$ Z B _s s %sjB R } JZ K tBR I js {B $ t j? { ${s j {Z }B B jBR 8? ZR{ZjBR I j 8$R8B -}Z R BR s RZ }sRB P { ? Zst {Bt s{{$Bt R $t%BjZt s $sR Ns 8? s-$8s }? I$Is I {B $ t } 8$ $Is t R ${BR {sAj R j? { ${BR D R Ys R sAj {$IB } T {ZsjJZ$ $tR sjs{$? Bt j? { ${s w j { BIB8? {$Rs8 t t Zt 8$j$s8} $B 7$ } R$R j {Bt s{ B {Bt js PZ t {BtIZ{ B s sj sZ8 t s j %sjB I js $t tR$IsI I js {B $ t R $t{ 8 t s js R tRs{$? Bt I IBjB k js s{{$? Bt 8ZR{Zjs {B R}BtI$ t et d( k 1( 8$j$s8} $BR js {B $ t $tY$A js s{{$? Bt I sj ZtBR 8? ZR{ZjBR $8}$I JZ js } RBts RZ j js PZ t =t ` 8}jB I }s sj$9s{$? Bt 8ZR{Zjs } BIZ{$IB }B {B $ t j? { ${s s}s { t Zts R{ ts I j hj8 et 8$ B 8? B >et 8k $t d MxHU Zt R sj$ t? ts I$R}Bt I Zt R$R 8s I } BT {{$? Bt I RZ ts% JZ R s{ $%s t {Zst B j YZ8stB G$jj$R *s%$I $t t s BAs j RZ s 8s V8ABR RBt RZ} %$%$ t R I Zts Z s JZ tP t s s RZR R} { $%sR s9sR k R % ? st {BtT I tsIBR s {BB} s t R? }s s RBA %$%$ t j $tY? BR}$ B }jst s 3k $t yz =ts RZ I } JZ K tBR skBR I } RZt B B $ t j? { ${B $t8B%$j$9st sj YZ8stB ej P t? B8 tB RZj s 8? sR B 8 tBR { ? Aj t j {Bt - B I {B $ t R j? { ${sR I $t tR$IsI 8BI sIs _s s Zts {B $ t j? { ${s I dM 8$j$s8} $BR R } BIZ{ js {Bt s{{$? Bt I jBR 8? ZR{ZjBR I j ? B s- JZ $tY$A j {${jB I js R}$ s{$? Bt tB 8sj I Zts } RBts 7$ tB R $t Z8} j {Bt s{ B {Bt j {BtIZ{ B R -} $8 t s Zts PsR I }? I$Is I j {BtB{$8$ t B JZ I R 8AB{s t js 8Z I j $tI$%$IZB t }B{BR 8$tZ BR V ZtBR d(( 8V j 8? ZR{ZjB {s I? s{B 8}$ 9s s sj$9s 8B%$8$ t BR $t{BB T I$tsIBR P t? B8 tB {BtB{$IB {B8B hA $js{$? Bt % t ${Zjs JZ $8}$I j AB8A B I js Rst Ns hA $js{$? Bt tB R I $ t }B R? RBjs k JZ$ s s8$ t B 8? I${B Z t 7$ ? R tB R } BIZ{ js 8Z R $t %$ sAj }B js {BtR {Z t I h{$ t{$s I $ $ s{$? Bt Rst Z? t s ;
=t s8} $B {B R}BtI s Zt 4Z`B I d(dM j { Bt R }B R ZtIB
© Los autores, 2001; © Edicions UPC, 2001.
dME
* $t Bt s e$tR $t
z s8BR sj ZtBR ` 8}jBR - s? IBR I js h{{$? Bt IBtI {Bt 8skB B 8 tB PB Zts R I R{ $A t R BR P { BR Ns 7 s V {Y js $t{ ? Aj 8Z` I dx 8 I j hj8 ej s sJZ I js 8Z` I x( }$ R >V s{, BP Y x( P GB8st d ;H htsj$9s RZ }sRB }B R 8ZtIB {ZstIB sj R s s{sIs }B Y j${? B} BR I j `? {$ B {s RBA jBR {sAj R I j tI$IB j? { ${B I sj B %Bj s` sZtJZ Bt2D i {B $Is R? BjB RZj s s Z I$Is w5 sj % 9 RZ I R{B8Ztsj 8sRs js Rsj%s I js j { B{Z{$? }B j B%t$ {sZRst I RZ $ st $R8B I R8 RZ sIB $t${$s ? s Zts tZ %s %$Is et js tB% js V s%? R I Zt 8s I RBj R >V{ BRR Y 7 s BP 7ZtR d M;H I p B k tPB I t{Bt s8BR Zts I R{ $}{$? Bt I js j { B{Z{$? Bt I Zts } RBtsU "ej R sjjs %$Bj t B k R {B Y$9B JZ R sj9s st jsR {sA 9sR sj I IB I js tB 8 {s {sRs 8$ t sR JZ j YB8A R R 8 {? s k s $ sAs I RsPB sIs8 t {Bt j %Bj s` } {$}$ ? stIBR }B RZ {Z }B k sA $? tIBj I Bj} RZ AB{s I js JZ R R{s}? B Zt RZR}$ B t {B sIB 7Z sR$R t {B8}s $? B s8A$? t js {B $ t IZ st Zt 8B8 t B sj -}stI$ R {js%? stIBj t j RZ jB V{ B R Z$IB js 8stB I j sR$R t k j A s9B RZP $ Bt Zt R}sR8B k ? R R I R} tI$? B I js s}s JZ RBR t? s {Bt jB JZ js {B $ t I `? B I {$ {Zjs }B ? j k R I R}jB8? B t js {ZA$ s R$t JZ jBR I 8? sR {sR$ R s} {$A$ st }Z R j } $8 YB8A R Rs{ZI? s k 8AjsAs st %$Bj t s8 t JZ BIB j 8ZtIB j BAR %sAs } $h{sIB et RZ $t $B jsR {? s8s sR { t sj R I AB8A B JZ YsA? st R sIB {B8 t9stIB s js`s R t RZ {${jB PZ Bt BA` B I Zts hA $js{$? Bt % t ${Zjs R s $ s Bt k t {YB{s Bt I t$ tIB j 4Z`B Rst Z? t B " et Zts R{ ts I js } j? {Zjs _s JZ FZ ? sR${B >FZ sRR${ _s , d 1H AsRsIs t js tB% js YB8? Bt$8s I ${Ys j ] ${Y Bt }Z I % R s Zt t$K tB JZ I R{$ tI }B Zts %sjjs j { $T h{sIs I R{Bt { sIs 8}B sj8 t 7 ? Zt jBR R$R 8sR I j { $h{s{$? Bt {Bt% t{$Btsj R Zts %sjjs R Zts RZ I {$ {Z$ B sA$ B I sj 8st s JZ R$ tB R B{s s js % 9 j RZ jB k j {sAj tB -$R }sRB I {B $ t VR? {ZstIB R {Bt { s js %sjjs R$ j t$K tB tB R ? s t {Bt s{ B {Bt j N Bt RZ jB tB I A ? s tB s t$t ? Zt P { B _B B B jsIB R$ YZA$ R R sIB RB8 $IB s Zts tR$? I d( ((( %Bj $BR R YsA ? s {s ABt$9sIB {B8}j s8 t et js tB% js R tB8A st Zts R $ I s 8sR I P tR$%sR }s s j {sRB I {Bt4${ B {Bt jBR I$tBRsZ $BR 7 YsAjs I jBR s Z I$IB R ? sR s 8sR j? { ${sR JZ RZ8$t$R st Zts tR$? Bt I 1 ((( %Bj $BR k JZ t } $t{$}$B tB I A ? st RZj s 8B sj R }s s st$8sj R I R s8sK tB tBR R} { s{Zjs R sZtJZ $ ZsjT 8 t P { $%sR t RZ {B8 $IB RBt jsR ? }${sR %sjjsR j { $h{sIsR JZ R$ % t }s s 8st t j stsIB t jBR } sIBR qs8A$? t t js } j? {Zjs ej sj$8 t B I jBR I$BR R >qY 3BBI BP Y pBIR d EH jBR } B s Bt$R sR Rsj%st js }s} j s 8B8 t ? st s8 t RB R? $8}$I$ tIB j s%st{ I jsR 8BtR ZBRsR s sR s $ st sIsR 8 I$st Zts %sjjs j { $h{sIs Vj B 8? sR RBhR ${sIB R j s $jZ $B t PB 8s I {Bjjs $I sIB }B _$ R Vt YBtk k iBA e s B& t RZ tB% js qY i$t >d EMH e8}js9sIB t j {Z jjB I Zt { $8$tsj j s}s s B R R tR$Aj s jBR $8}ZjRBR st $RBT {$sj R I RZ }B sIB k s{ ? Zs {sR $ ? stIBjB {Bt Zts I R{s s j? { ${s eR sR $I sR s8A$? t RBt Z $j$9sIsR t } j? {ZjsR {B8B _ j$ BRs8 t Zt$IBR >G IjB{, d dH k _ R Z$IB >qY iZtt$t st d M H et js } $8 s jBR {Bt%${ BR s JZ$ t R R Ys $8}jst stIB Zt {Bjjs R$8$js tB }Z I t sj `s R 8? sR sjj? s I Zts {$ s I$R st{$s I js } $R$? Bt RB } ts I JZ js s{ $%s{$? Bt I j s}s s B 8$t }B I R{sA 9s jBR VRB{$sIB s R s $I s -$R s8A$? t js R $8Zjs{$? Bt I { t BR I }js{ JZ }Z I t }B t{$s 8BI$h{s B {BtI${$Bts js {BtIZ{ s et ZtIB st$jjB ! !
Ns } R t{$s I {BtI tRsIB R t Zt {$ {Z$ B j? { ${B }Z I B $ $ts {B $ t R stR$ B $sR {ZstIB R sA B R {$ s j 8$R8B JZ }Z I t t sj ? Zt P { B } %$B s js $tR sZ s{$? Bt I j ? $8 t R s{$Bts $B
N
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
dM
3$ ; ; ej $t% R $ sIB P st{? R ]Ys j R 3 sta {B$R I ]$R tsk *Z 3sk wdE MTd n D PZ j } $8 B t I 8BR s js {BtIZ{{$? Bt j? { ${s t j {Z }B YZ8stB ]Bt j } 8$RB I j k NZ$R yz *Z 3sk I$R}ZRB s dM( RBjIsIBR P st{ R R t hjs Zt$IBR ZtBR s B BR Vj s}j${s j sj } $8 B I Zt - 8B Zts PZ I R{s s j? { ${s BAR %? B {? B8B ? R s R stR8$ ? s sj R B JZ }B P { B I js {B $ t j? { ${s $Ast Rsj stIB ej sAsI F st Zt 8? sR j `BR i }$ $? B js -} $ t{$s {Bt P s$j R {s Z`BR Zt$IBR ZtBR s B BR Vt B$t WBjj wd ((Td (D PZ s? {Bt Zt Y$jB {BtIZ{ B 8 ? sj${B JZ PB 8sAst Zts {sI ts YZ8sts I n ,8 I jBt $ ZI NBR P { BR BAR %sIBR PZ Bt R$8$js R >i$t bB jI d (H I Ns k W$% t j R8$ $sIB - s R JZ PB 8s }s I js -} I${$? Bt JZ %$R$ s j - sK tB ZtIB st$jjB Z $j$9s Zt R$8}j I$R}BR$ $%B I s sJZ JZ s{ ? Zs RBA jBR { t BR I }js{ }s s I P tI R I $tB}B ZtBR t 8$ BR
Ns R$R t{$s j? { ${s I j {Z }B YZ8stB I } tI I RZ R sIB k }Z I R$ Zs R t jBR s 8}s}sIB I s Zs RsjsIsD YsR s jBR x(( ((( BY8$BR w t j d(( BY8$BR w{ZstIB j {Z }B R ? {sRB I }$ j R {sD et {B8}s s{$? Bt js R$R t{$s I Zts AB8A$jjs I hjs8 t B ? }${s R I
ZtBR d(( BY8$BR 8$ t sR JZ j {sAj I sj$8 t s{$? Bt $ t Zts R$R t{$s $tP $B s d BY8$B Bt t jBR {$ {Z$ BR j? { ${BR IB8? R ${BR q tR$Bt R I ZtBR }B{BR { t ts R I %Bj $BR wjs tR$? {B8Zt R R I 11( %Bj $BRD }Z I t R RZh{$ t R }s s } BIZ{$ {B $ t R j? { ${sR } j$ BRsR s s%? R I j {Z }B VR ? 8Z{YBR s{{$I t R IB8? R ${BR R } BIZ{ t {ZstIB {Bt js }$ j 8B`sIs k {Bt Zt 8sj s$Rjs8$ t B j? { ${B I j RZ jB w}$ R I R{sj9BR }B ` 8}jBD R t s t {Bt s{ B {Bt R {sIB R { NBR t{YZP R I {Bt -$? Bt I jBR s}s s BR j? { ${BR {Bt js PZ t I tR$? Bt s{BR Z8A st s t Zts }s
t Z s
JZ } 8$ I $%s s $ s js {B $ t t {sRB I s{T
{$I t Ns j { B{Z{$? Bt s}s { t I$P t R } j? {ZjsR {B8B 8 {st$R8B }s s I RYs{ R I t R js PB 8s I j$8$ts s sj ? Zt JZ B B 8shBRB } B RB R ks 8$Aj R sj$ t ? tsR w s8A$? B s Y$R B $sD e` 8}jBR jBR t{Bt s8BR t
ej -} $8 t B I j * +Zs 8sRR >qY +Zs T
8sRR } $8 t d xxH IBtI IZ st Zt %Z jB R}s{$sj Zt %$ ZR I ts Z sj 9s - s R R $t BIZ{ t j {Z }B I ZtB I jBR sR BtsZ sR k } B R$%s8 t jB %s stRPB 8stIB
© Los autores, 2001; © Edicions UPC, 2001.
dMM
* $t Bt s e$tR $t
3$ ; x ej { B{Z{$? Bt I js { $s Z s % sj I ej t$ 8s I B B 8ZtIB >qY qY$t d xdH t Zts R} {$ I }jst s 3$tsj8 t j t tI B R j { B{Z sIB t js sAsI? s jBtI$t tR I G R 8$tR =ts R$ Zs{$? Bt R$8$js R }jst s t js } j? {Zjs {j? sR${s ej t$ 8s I B B 8ZtIB >qY qY$t d xdHU Zt sj$ t? ts I sR} { B YZ8stB$I } B I {BtR $ Z{$? Bt R t{$sj8 t % sj R YsjjsIB t j }BjB k {B $IB }B Zts -} I${$? Bt {$ t ? h{s ej }B{B s8$ sAj -T s R R t Z sj$9sIB s{$sR s Zts R t{$jjs $t t$BRs s8}s j? { ${s ej sj$R8B I js j { B{Z{$? Bt I j R R }s t s8A$? t t j {s8$tB JZ R$ Z t jBR skBR j? { ${BR } BIZ{$T IBRU R BR R I$ $ t s jBR - 8BR I j {Z }B w{sA 9s - 8$IsI RD jZ s R IBtI R$I Zts 8skB s{Z8Zjs{$? Bt I {s s j? { ${s t Zt {BtIZ{ B ej P t? B8 tB R {BtB{ {B8B P { B }Zt s B }s s skBR et js } j? {Zjs ej IB{ B 3 st, tR $t - Zt {$ t ? h{B j As ? Bt z? { B 3 st, tR $t BAR R$BtsIB {Bt js $I s I { s %$Is BAs {sI? s% R I jBR { 8 t $BR }s s RZR -} $8 t BR {Bt js skZIs I RZ h j skZIst j I PB 8 3 $ 9 =ts tB{Y t RZ jsAB s B $B {BtR$ Z $tPZtI$ %$Is s Zt {sI? s% {BtR Z$IB s AsR I P s 8 t BR I } RBtsR 8Z sR k sj JZ }B B j Ys $8}jst sIB j { A B I Zt I 8 t ej R 8BtR ZBRB B ts s js %$Is s{$sR sj s}s s B
WB R ? R s js } $8 s } j? {Zjs RBA j 8$ B sZtJZ R? js 8? sR {BtB{$Is k Ps8BRs Vj 8 tBR IBR {$t sR YsA ? st % R$BtsIB {Bt st $B $IsI js tB% js I s k 7Y jj kU Zts I j sK tB d d( sj$9sIs }B js {B8}sK t? s { sIs }B j } Bj? h{B $t% t B tB s8 ${stB qYB8sR V eI$RBt wdM; ud ndD k B s I d dx N$P b$ YBZ 7BZj et ? R s Z ?j $8s Zts `B% t s B} jjsIs }B Zt {B{Y R I %Z j s s js %$Is }B js s{{$? Bt I Zt $}B I skB j? { ${B $t% t sIB }B RZ }sI -
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
dM
j? { ${B I Rs sIB IZ st Zts 8} R sI 5]Z? sj R ? s j P { B sj I js {B $ t j? { ${s JZ s{B8}sK ts sj skB RBA I${YB {Z }B YZ8stB2 5eR js j { ${$IsI js PZ t I js %$Is sj {B8B R -}j${$ s t j hj8 2 Ns RZ} h{$ R R ? s {s sIs t s $%s8 t eR s {s s j? { ${s R $tIZ{$Is }B j {s8}B j? { ${B JZ -$R t js }s RZ} $B I js s 8? BRP s ws ZtBR E( ,8 I sj Z sD k js } B}$s RZ} h{$ R Ns tR$? Bt -$R t t R sR IBR $Bt R R I ZtBR ;(( ((( %Bj $BR {Bt Zt {s8}B j? { ${B I ZtBR d(( %Bj $BR }B 8 B { {s I j RZ jB V } B}? BR$ B I R {s8}B j? { ${B ZtB }Z I } Zt s R }B JZ? tB tB s8BR tsIs {ZstIB t sj$IsI I A ? s -$R $ Zts I$P t{$s I }B t{$sj B tR$? Bt t tZ R s {sA 9s k jBR }$ R I { {s I 1(( %Bj $BR 57 ? s R s js s9? Bt I }B JZ? jBR `Z sIB R I AsjBt{ R B Z $j$9st 9s}s $jjsR I B8s AZ tBR s$Rjst R j? { ${BR2 Ns R}Z R s R JZ IsIB JZ j {Z }B YZ8stB R { ${B sj 8 tBRD RZ 8 s } R t{$s I PB 8s j {s8}B Zt js $%s8 t AZ t {BtIZ{ B wg j? j? { ${B I 8st s JZ st B js {sA 9s {B8B jBR }$ R sR? {B8B j R B I j B st$R8B R t{Z t st s js 8$R8s tR$? Bt WB Ysk }B st B {B $ t j? { ${s eR s 8$R8s R$ Zs{$? Bt R Is {ZstIB sR Zts $8} R$Btst {s? Is j Y? B I Z tB R sP s t Z ?j $8s $tR st{$s s jBR {sAj R I j tI$IB j? { ${B Rsj%? stIBR I j $8}s{ B {Bt s j RZ jB k R$t }sI { jBR P { BR I js j { B{Z{$? Bt NBR {sAj R stR}B st js t ? s j? { ${s I RI jsR { t sj R j? { ${sR IBtI R } BIZ{ YsR s jBR jZ s R I {BtRZ8B s tR$Bt R j %sIsR I j B I t I { t ts R I 8$j R I BtD }s s 8$t$8$9s jsR }? I$IsR t ? ${sR }B {sj t s8$ t B I jBR %Bj $BR w{sAj R I sj s tR$? {BtIZ{ B R sj }sRB I js {B $ t j? { ${sU j I tB8$tsIB P { B FBZj ]B8B R YsA$ Zsj j Y? B RZj s R$ 8} $j RB sj {Bt s{ B {Bt Zts tR$? Bt j? { ${s j %sIs k }B Zts % 9 Pst sR? s k sj$IsI R {Bt{$j$st et } R t{$s I Zts tZA B 8 t BRs js tR$? Bt t js }s $tP $B I js tZA R$ ZsIs s ZtBR 1 ((( 8 BR I sj Z s k js RZ} h{$ R sj{st9s jBR d(( 8$jjBt R I %Bj $BR NsR tZA R {s sIsR t s $%s8 t $tIZ{ t js s}s ${$? Bt I {s sR }BR$ $%sR t js }B {$? Bt I RZ jB R$ ZsIs I$ { s8 t I As`B eR %Bj s` st sj B {B8}B s js Z} Z s I$ j? { ${s I j s$ JZ R Zt 8 I$B s$Rjst I PB 8s JZ ? R R $Bt$9s k R {Bt%$ t {BtIZ{ B k } 8$ sR? js j$A {$ {Zjs{$? Bt I jsR {s sR j? { ${sR JZ R 8Z % t } B%B{stIB Zts s%sjst{Ys k PB 8stIB Zt skB Ns {s? Is I skBR R {Bt{ t s t jsR $Bt R 8? sR }Zt $s ZIsR jsR {Zsj R } R s R s Bt s js 8$R8s tR$? Bt JZ j R B w t {Bt s{ B {Bt j RZ jBD } R t st Zts 8skB {Bt{ t s{$? I {s s j? { ${s ej %sjB R $8sIB I js $t tR$IsI I {B $ t j? { ${s t Zt skB ? }${B R I ZtBR 1( ((( s8} $BR ej 8BtR ZB I 3 st, tR $t JZ RZ { sIB } tI %$%$ R ? s {B $IB }B Zts $t tR$IsI I R B I t sj R -}Z R B I$ { s8 t s js s{{$? Bt I Zt skB i {B I 8BR JZ d(( 8$j$s8} $BR RZj st 8B sj R }s s Zt R %$%B tB sR? }s s js { s{$? Bt I j As ? Bt 3 st, tR $t JZ R ? s {BtR Z$Is s }s $ I P s 8 t BR I {sI? s% R YZ8stBR e-$R tB BAR st B B P t? B8 tBU j }sRB I Zts {B $ t j? { ${s {B8}B s s8A$? t js t s{$? Bt { ${sR k jsR AB8A$jjsR t I {sjB w R j P { B FBZj AsR I j PZt{$Bts8$ t B I jsR R ZPsR j? js -}BR${$? Bt s $t tR$IsI R - 8sR j `BR I %$%$ sj 8BtR ZB I 3 st, tR $t B BRD VR? gI A ? s JZ 8s RZ {Z }B $t 7$t 8As B R$ 8} }Z I } tRs R t j ZRB I sj ? Zt I$R}BR$ $%B j? { ${B w{B8B Zt stRPB 8sIB D }s s IZ{$ j %sjB I js {B $ t JZ {B j {sI? s% _ B }s { {js B JZ js -}BR${$? Bt I$ { s I Zt {Z }B s Zt skB } B%B{s t j 8 `B I jBR {sRBR RZ j { B{Z{$? Bt WB Ysk JZ {BtPZtI$ }Z R jsR R $8Zjs{$Bt R {s I$s{sR
© Los autores, 2001; © Edicions UPC, 2001.
@
* $t Bt s e$tR $t
3$ ; E ej IB{ B z? { B 3 st, tR $t } }s stIB RZ -} $8 t B }s s $tPZtI$ %$Is s Zt {sI? s%
}B j { B{YBJZ R {Bt j $t t B I st$8s Zt {sI? s% Z $j$9stIB {B $ t R j? { ${sR I st $t tR$IsI 5_Z I RBA %$%$ R s js {s? Is I Zt skB2 7? R$ 8} JZ j }sRB I js {B $ t tB s s%$ R jBR B ? stBR $t tBR %$ sj R et jBR I? sR I jjZ%$s }B ` 8}jB j skB }BI ? s I R}js9s R }B js B}s 8B`sIs B }B js }$ j Y? Z8 Is w8 `B {BtIZ{ B s JZ js }$ j R {sD R$t } BIZ{$ 8? sR JZ JZ 8sIZ sR RZ} h{$sj R sj $tI$%$IZB eR s R$ Zs{$? Bt R Is t hj8 R {B8B 3jsRY j j? s8}s B YZ8stB >qY 3jsRY d (T dH IBtI {B8B ks {B8 t s8BR t j {s}? ZjB n Zt }Bj${? s sIJZ$ RZ} }BI R sR {$A$ j $8}s{ B I Zt skB 8$ t sR sj$9sAs ZtsR } Z AsR {Bt } BIZ{ BR JZ? 8${BR B t NBR $t8B sj R ><$ YjstI d MEH IBtI Zt 8$ 8A B I j {jst s{]j BI RBA %$% s js {s? Is I Zt skB _B B B jsIB R? BjB t R BR {sRBR R {ZstIB }Z I % R j j? s8}s B k R t $ RZ s{B8}sK ts8$ t B RBtB B j Z tB sj 8$R8B $ 8}B et js Z ?j $8s } j? {Zjs {$ sIs $t{jZRB }BI 8BR t{Bt s Zts js{$? Bt -}j? {$ s t js j { ${$IsI k js $t8B sj$IsI NBR $tI$%$IZBR $t8B sj R I js 8$R8s wk I RZR R {Z jsR }Z R j 8s Ys IsIB }B j 8B8 t B }s s IBR hj8 R 8? sRU NBR $t8B sj R yyU j I RsP? B ><$ YjstI yyU qY +Z${, t$t d (H k NBR $t8B sj R yyyU j Y {Y${ B ><$ YjstI yyyU qY 7B { >d EHD R? BjB }Z I t } I RZ {BtI${$? Bt I $t8B sj sj R j R AstsIs js {sA 9s {Bt Zts R}sIs ]sA } tRs JZ jBR Z$Bt$R sR {BtR{$ t R I js }s sIB`s JZ RZ}Bt 8s s s Zt R $t8B sj wgR$ }Z I } { t Bt{ R tB }BR j s $AZ B I $t8B sj$IsI D Yst JZ $IB I$R{Zj}s js $t{Bt Z t{$s {B8 $Is $t BIZ{$ tIB R$t } tRs sj ZtsR B sR 5]? B8B R$ tB R -}j${s JZ sj {B s js {sA 9s I Zt $tI$%$IZB $t8B sj RZ `s Zt s8$jj I skBR {Zsj h R s % A t s2
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
@ @
3$ ; 7$t {B8 t s $BR 5eR JZ js s9s I jBR $t8B sj R }BR Zts sj s {Bt{ t s{$? Bt I t ? s JZ RZj s j$A sIs t {Zst B R j R I {s}$ s2 ! A$ t 5 R JZ Zts % 9 8Z t R Ysjjst s Zt }B t{$sj j? { ${B 8skB JZ RZ t B tB s{$sR s jB {Zsj {B8B R$ I Zts tZA B 8 t BRs R s s s R } BIZ{ t jBR skBR2 O ks }Z R BR 5I I? BtI } B{ I k {? B8B R B $ $ts j PZ %$ t B JZ As j jZ s {ZstIB R B RZ{ I 2 et i RB sj PZ Z B > s{, B Y 3Z Z d MxH R Z $j$9s Zt skB }s s {BtR Z$ jBR d, x 8 s%s $BR I }B t{$s j? { ${s t { Rs $BR }s s Ys{ PZt{$Bts js 8? sJZ$ts I j $ 8}B JZ Ys I B ts s s k {3jk sj 1E I B{ ZA I d Mx I RI j sK tB d xx 7 $t t s {stsj$9s BIs js {B $ t j? { ${s I Zt skB Ys{$ tIB ZRB I Zt {sAj _ B t j 8B8 t B t JZ {s j skB j {sAj R t{Z t s I R{Bt { sIB W$ {B B t$ } 9BRB j {$ t ? h{B *B{ Bbt {B jBR IBR - 8BR I j {sAj k } 8$ sR? JZ js {B $ t j? { ${s jj Z sj {B{Y gO R$t RZP $ t$t ? Zt IsK tB s}s t ! BR $t% R $ sIB R R BR R? sj R P? R${BR I {s t k YZ RB tB Z%$ Bt st s RZ =t sK tB I R}Z? R I jsR Ps8BRsR -} $ t{$sR I t`s8$t 3 st,j$t wd (ET d (D {Bt jjs% R k {B8 sR wd x1D j } BP RB i ${Y8st I 7st _ RAZ B YsA? s $tR sjsIB t j `sIB I RZ {sRs Zt }s s skBR }s s {s} s js j { ${$IsI s 8BRP? ${s k {BtIZ{$ js s Zts RP s R$ ZsIs t RZ jsAB s B $B Vt js 8$ sIs s ? Bt$ s I RZ skZIst RZj ? B PZj8$tsIB }B js I R{s s I Zt skB g ? s $ R $ t js {$ t{$s et j {B B8 s` 3 st, tb t$ >d M;H I$ $ $IB }B q$8 Z Bt Zt t$K tB %$% s RZ } B 8Z B Z $j$9stIB js I R{s s j? { ${s I Zt skB t Zt {js B YB8 ts` sj hj8 ej IB{ B 3 st, tR $t Vj $ Zsj JZ t ? R j st$8sj 8$ts }B 8B $ s 8stBR I jBR YsA$ st R I j }Z AjB JZ $t{ tI$st j 8Bj$tB IBtI R Ys PZ $sIB _ B sj htsj g %$% t sj st$8sj Z $T j$9stIB jsR As ? sR I Zts IB{ ts I sZ B8? B%$j R Ns tR$? Bt j? { ${s JZ }Z I B $ $ts R {Bt jsR IB{ As ? sR I R tIBR sZ BR {Bt { sIsR t R $ R I d1 d1 z ) d;; %Bj $BR VZtJZ R ? s
© Los autores, 2001; © Edicions UPC, 2001.
@
* $t Bt s e$tR $t
{js B JZ t$ }B RsR j {sI? s% I j st$8sj B ts ? s s js %$Is t R {sRB }B jB 8 tBR tB T RZj s ? s {Ys8ZR{sIB s {sZRs I j P { B FBZj _Z I R sAj { R Zt }s sj j$R8B t jBR P { BR I js {B $ t j? { ${s RBA jBR R R YZ8stBR k j ZRB I skBR }s sj$9st R Y$}B ? ${s8 t {s}s{ R {B8B Y 8BR {B8 t sIB t j s}s sIB st $B I $t8B%$j$9s Zt B st$R8B IZ st Zt {$ B $t %sjB I $ 8}B =t R %$%B }Z I JZ Is $t{BtR{$ t {B8B RZj sIB I js -}BR${$? Bt s Zts {B $ t j? { ${s I I 8$tsIs $t tR$IsI et qY q$8 q s% j R >d E;H }B ` 8}jB sj $t t s } t s t Zts {Z %s } B $Is }B Zt {s8}B j? { ${B jBR 8Z st R $t%sRB R RZj st }s sj$9sIBR {B8}j s8 t 7$t 8As B j R sIB I $t{BtR{$ t{$s tB } T 8$ $ ? s JZ R 8st Z%$ R t $t8? B%$j R I }$ st js t sIs {B8B R$ sj {BRs R$tB JZ s{sAs ? st {Bt RZR YZ RBR t j RZ jB s {BtR {Z t{$s I js }? I$Is I {BtR{$ t{$s VI 8? sR ? R tB R j $}B I P t? B8 tB JZ ZtB R} s ? s t{Bt s sj s s% Rs Zts $? Bt IB8$tsIs }B Zt {s8}B j? { ${B * Y {YB I A ? s I }BI sR}sRs R R$t I 8sR$sIBR } BAj 8sR e` 8}jBR R$8$js R R 8Z R st t hj8 R {B8B 7 s q , >7 s q , T qY B $Bt _${ Z d H B t R $ R I qz {B8B eR}s{$B d >7}s{ d d xT H <sk JZ } tRs }Z R t B B B $ t }s s R $}B I s $jZ $BR I P tR$%BR }BR$Aj 8 t j I j 8ZtIB I js Pst sR? s _Z R BR s }s sj$9s jsR {BRsR jBR Z$Bt$R sR I js } j? {Zjs =j $8? s Z8 s js q$ s >qY *sk Y es Y 7 BBI 7 $jj d xdH I R s{st t B BR Zt sR} { B $t Rst t js{$? Bt {Bt j 8s JZ tBR B{Z}sU js t Z sj$9s{$? Bt I js j { ${$IsI I BIB j }jst s IZ st 8 I$s YB s i RZj s I$P? {$j $8s $ts Zt 8? BIB h{s9 }s s j$8$ts js j { ${$IsI I BIs js q$ s {B8B tB R s js $t Z}{$? Bt I j 4Z`B I {s sR I R Zk tIB }s s jjB jBR } B}$BR I$R}BR$ $%BR {BtIZ{ B R I js {B $ t 5]? B8B }Z I }s s R Zt sZ B8? B%$j s{{$BtsIB }B RZ As ? s j? { ${s B jsR stR8$R$Bt R sI$BP? Bt${sR B j %$R$%sR R$t Ys{ {s jBR s%$Bt R JZ stR$ st }B j 8$R8B 8 I$B2 Ns j$8$ts{$? Bt I BIs PZ t I tR$? Bt j? { ${s t js q$ s {B8}B s ? s s8A$? t P { BR RBA jBR YZ8stBR IsIB JZ s t$% j { jZjs -$R t I$P t{$sR I }B t{$sj j? { ${B JZ {BtR $ Zk t js AsR I j PZt{$Bts8$ t B I jsR t Z BtsR k I BIB j R$R 8s t %$BRB 7$ }s s }s s js j { ${$IsI I BIB j 8ZtIB j BAB - s R pB t Z sj$9s jsR I$P t{$sR I }B t{$sj j? { ${B t js q$ s jBR R R %$%BR }sI { ? st $8}B st R sj s{$Bt R wjB {Zsj R ? s t {$ B 8BIB {Bt sI${ B $B {Bt j jBsAj BA` $%B I js 8$R$? Bt sj$ t? ts I } R %s s s%? R I R % sR sI% t{$sR js s9s YZ8stsD WB BAR st R$ R j$8$tsR t BIsR jsR PZ 9sR j? { ${sR t } B Bt R k j { Bt R I jBR s ? B8BR 5JZ? RZ{ I ? s2 57 I R$t s ? st jBR YZ8stBR jBR BA` BR k BIs js q$ s2 eR B }BI ? s -}j${s }B ` 8}jB js I R$t s{$? Bt I }$R BjsR PZR$j R stJZ R k {ZsjJZ$ s 8s8 t B I jBR ? {BjsR {ZstIB j BAB jst9s RZR }BI BRBR skBR VZtJZ {B8B RZj sIB jBR RBjIsIBR JZ }BR t R sR s 8sR {$A$ ? st Zts jjZ%$s j sj I j { Bt R t Z Bt R k B sR }s ? {ZjsR JZ s{sAs ? st {Bt RZR %$IsR et es Y % RZR Y 3jk$t 7sZ{ R >d xEH jBR {$ t ? h{BR R R stsj$9st j {sR{B Z $j$9sIB }B jBR sj$ t? tsR $t%sRB R _s s -}j${s jBR }BI R JZ {Bth t s JZ$ t jB jj %s }Z R B ws8}j$h{s{$? Bt I %$R$? Bt k I RBt$IBD R} {Zjst RBA js ts Z sj 9s I j 8$R8B k s Z8 t st JZ R ? s {BtR $ Z$IB g}B j { ${$IsI R? Bj$Is 5WB RZj s 8 tBR $t% BR? 8$j I {$ JZ R ? s {BtR Z$IB {Bt Zt 8s $sj JZ tB R t{Z t s t js q$ s2 "zZ R s j { ${$IsI R I$R $t s I js tZ R s" -{js8s j - s R JZ Ys % t$IB s js q$ s t AZR{s I Zts 8sI I sjJZ$j ? {Bjs {Bt JZ$ t } } Zs RZ s9s t js } j? {Zjs ej $t%sRB >qY yt%sI d M H O sK tsI "gq$ t 8Z{Ys 8? sR }B t{$s " Ns j { ${$IsI {B8B } B}$ IsI PZtIs8 t sj I js
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
d n
ts Z sj 9s R js 8$R8s sJZ? t j }jst s I B $ t I j sj$ t? ts k t {ZsjJZ$ }s I j Zt$% RB et BIB {sRB RBt s $AZ BR sj R {B8B js P {Z t{$s I js {B $ t sj ts s js {Zsj R RZ8$t$R s YsA$ Zsj8 t js t ? s j? { ${s w t eZ B}s x( Y 9$BR t eR sIBR =t$IBR E( Y 9$BRD B js tR$? Bt I js j? t s wd1( 11( B nE( %Bj $BRD jBR JZ }Z I t R I$P t R _B B B jsIB j sj$ t? ts 8sj%sIB JZ I A $8} I$ JZ j st $B {BtR$ s RZR } B}? BR$ BR R 8Z{YB 8? sR ? s}$IB PZ k R$R t JZ RZ YB8? BjB B sZtJZ s js }BR RZj s j { B{Z sIB 7BjZ{$? Bt }B{B B $ $tsj } B }B jB JZ R % P { $%s k 8Zk ZRsIs {ZstIB AsjsR Bj} R k I 8? sR RZj st $tRZh{$ t R
; n
e8ZjstIB s jBR I$BR RU { sR }s s js $t8B sj$IsI
Ns $t8B sj$IsI R I {$ js }BR$A$j$IsI I %$%$ }s s R$ 8} R B s 8st s I {BtR Z$ RB s js $t jZI$Aj { 9s I js 8Z P? R${s WB R s s sYB s I Z $j$9s I PB 8s } $Is sj ZtB I jBR 8? BIBR I RZ {{$? Bt JZ Y 8BR {B8 t sIB R$tB R$8}j 8 t I tB jj s s JZ s{Bt 9{s j Y {YB 8$R8B I js 8Z 7 s s I {Z} s }s s jBR YZ8stBR Rs {s s{ ? R ${s JZ jBR I$BR R I j !j$8}B R %sAst }s s R? 8$R8BR Os js j tIs $s A? ZRJZ Is ? I j 7st B p $sj js 8? ${s {B}s Z $j$9sIs }B F RZ{ $R B IZ st js =j $8s ] ts k JZ {Bt{ I s JZ$ t A A I jjs j IBt I js $t8B sj$IsI ws Z8 t B }B B s }s BA` B I jsR s% t Z sR I js { s t s I js R $ RBA j Y? B k s% t Z B }B -{ j t{$s ytI$sts FBt RD sR? {B8B I js PZ t I js ts `Z% t ZI JZ `Zt B s js sR8Z s{$? Bt I js 8s $s t B B st B AZR{s Bt jBR sjJZ$8$R sR 8 I$ %sj R {BtR $ Zk t B sR st sR s} B-$8s{$Bt R t R {sRB 8? s ${BT j$ $BRsR sj 8s I js $t8B sj$IsI Ns R} {$s JZ R { ? s t j I R? ${B }jst s V s,$R I *Zt >d ExH js Rs s R{ $ s }B 3 st, < A B js I B s I js tB% js qY k 7Ysjj <s% 7 s R >d xEH I Fs8 R j$RY JZ s{ ? Zst }s s RZR {BtRZ8$IB R {B8B sZ ? t ${BR j$-$ R I js %$Is R ? st jsR % R$Bt R 8BI t$9sIsR I R BR } BIZ{ BR 8$js B Ns P {ZtI$IsI {$t 8s B ? sh{s RBA j 8s I js ts `Z% t ZI RZj s tB sAj sj 8 tBR t jBR } $8 BR sK tBR I -$R t{$s I j {$t et j R $sj qY 7{ s8$t 7YsIBb >d 1(H FBYt istI Zt YBt R B {$ t ? h{B R tP t s s RZ 8sj%sIB YB8? BjB B j As ? Bt z jR,s I Z Bt$s }B js BA t{$? Bt I Zts P? B 8Zjs JZ B B Z j IBt I js jBt %$IsI k {Zks j `sts $8}BR$Aj AsR A$Bj? B ${s R$I t Zts RZAR st{$s - s? Is I jsR j? stIZjsR I j 8BtB 3ZtIs8 t B $I? t ${B sj }jst sIB t Ns BAR R$? Bt I Zt RsA$B 7 ? Zt }s { R sR $I sR % t? st $t4Z t{$sIsR }B js }ZAj${s{$? Bt t js } tRs tB s8 ${sts I sj ZtBR s ? {ZjBR t jBR JZ R IsAs PZtIs8 t B {$ t ? h{B s js }BR$A$j$IsI I JZ jsR j? stIZjsR I {$ BR st$8sj R w t }s ${Zjs I j 8BtBD }BI? st {BtR $ Z$ js PZ t I js ts `Z% t ZI et ej jsI ? Bt I j? stIZjsR >d xEH I G t{ RjsB 3 t? stI 9 3j? B 9 Fs$8 eR{BAs Zt `B% t I j 8Bt ? Bt {$A Zts {Z $BRs } B}Z R sU { I RZR j? stIZjsR sj 8$jjBts $B s t $tB WB A B V sj 8$t t {$ t ? h{B VR? ? R }BI ? s }BR s RZ t% ` {$8$ t B k {Bt $tZs RZR $8}B st R $t% R $ s{$Bt R VY? R tsIs s } R t t ej 8s I j `Z% t {$8$ t B w} R %s js `Z% t ZI B %Bj% s R `B% tD R ? hj8 R {B8B ej } {sIB I %Bj% s R `B% t IBtI Zts 8? sJZ$ts I skBR I %Z j% s jBR n( sK tBR I IsI s Zts st{$sts {BtI Rs 7$tt R $t 7$j, B zst$ k:R _ $9 BIsR jjsR I j sK tB d 1; et qY OBZt *$sts >d 11H $tR}$ sIs t js tB% js ej s B I *B $st p sk >qY
© Los autores, 2001; © Edicions UPC, 2001.
d ;
* $t Bt s e$tR $t
_B s$ BP *B $st p sk dM dH I !R{s G$jI R Zts `B% t js JZ RZ{Z8A s js t s{$? Bt I B8s j j$-$ I js ts `Z% t ZI $tIZ{$Is }B Zt R$t$ R B IB{ B et js {j? sR${s {B8 I$s R$ t B `Z% t { > Bt, k ZR$t RR d x1H Zts }s `s 8BI? j${s R stRPB 8s t Zt }s I P t? ${BR sIBj R{ t R sR js $t R $? Bt }B B I Zts RZR st{$s `Z% t { IB s ! BR hj8 R {B8B !t Gsk 7 >d 1xH k $IR s8 >d 1 H sAB Ist j 8s I j `Z% t {$8$ t B I RI js B ?} ${s ks 8? sR % BR? 8$j k st t AB s YBk I? s I jsR B} s{$Bt R I {$ Z ? s R ? ${s k I jBR s s8$ t BR `Z% t { IB R eR ZRB I jB JZ t {sIs 8B8 t B I js Y$R B $s R t $ tI }B R ? ${s8 t {B { B s}s { I PB 8s $tJZ$ st t Zt }$RBI$B I js R $ I qz Ns I$8 tR$? Bt I R{BtB{$IsU t js RB{$ IsI YZ8sts I j PZ Z B RBjs8 t R ? st } 8$ $IBR ZtBR {Zst BR 8BI jBR I s}s $ t{$s WB Ysk jZ s }s s jBR I$P t R jBR P BR ]ZsjJZ$ R YZ8stB {Zks A jj 9s tB R s`ZR sj }s ? Bt R sAj {$IB R {Bt% t$ t 8 t stRPB 8sIB sR R $tIZ{$IB s j $ j 8BI jB VZtJZ ZtB R } Zt s R$ t Zts RB{$ IsI IBtI BIBR RBt R ? ${s8 t } P { BR R ? Zt jBR {? stBt R I js 8$R8s 5tB R ? s t { Rs $B j {Bt sR js } R t{$s } 8st t I js P sjIsI I js I$P t{$s JZ sj9s Rs A jj 9s2 et js } j? {Zjs qY GsR} GB8st >d x H Zts ` {Z $%s I IsI s%st9sIs I Zts 8} Rs I {BR8? ${BR B8s }s s `Z% t { Zt } }s sIB s AsR I `sj s sj I s%$R}s I R{ZA$ B }B Zt jB{B s}${Zj B VZtJZ }B jB JZ R % tB {BtR$ Z j P { B I R sIB ]Bt% $Is t Zts 8BtR ZBR$IsI R I I${s s Rs{$s RZ s} $ B {Bt $t{sZ BR YZ8stBR 5VI? BtI PZ s }s s sJZ jjs "{$t Z s I s%$R}s"2 Z{YBR RBt jBR 8? BIBR k } B{ I$8$ t BR wh{ ${$BR {js BD JZ R Yst } B}Z R B }s s sj{st9s js $t8B sj$IsI _Y$j$} FBR? 3s 8 t V %Z R BR {Z }BR I$R} RBR >qB OBZ 7{s I BI$ R pB d dH } $8 s t s I j {${jB ej 8ZtIB I j ? B $8s $ts Zt }jst s s s% RsIB I }s s }s }B Zt Z ?t${B k {sZIsjBRB ? B {Zks PZ t R I R{BtB{$Is k s {ZksR B $jjsR %st s }s s BIBR jBR R R 8Z BR RBA js q$ s k RZ{$ sIBR }B Zts 8$R $BRs k - sK ts t $IsI I R 8ZtIB {ZksR 8B $%s{$Bt R } 8st { t B{Zj sR Ns RZAR$R t{$s R ? s sR Z sIs k s8A$? t js RZ {{$? Bt sR {ZsjJZ$ $}B I 8Z VR? % RZ - sK ts R$ Zs{$? Bt j } B s Bt$R sU "<sA? s 8Z B VYB s R sAs %$%B *Z st BIs RZ %$Is R YsA? s ? IB I js $I s I JZ YZA$ s Zts %$Is I R}Z? R I js 8Z _B Zts % 9 tB }BI? s t s JZ R YsA? s JZ$%B{sIB _ B tB YsA? s tsI$ } R t }s s -{js8s U gOs jB I$` 8sjI$ B $t{ ? IZjB " et Ws{$IB {Bt jBR 8Z BR > B t b$ Y Y * sI d ;H I iBA 7$j% A j } {$B }s s } BjBt s js %$Is R 8B $ t } $8 jZ s }s s jZ B {Zsj V% 3? t$- R st$8sIB NBR I$PZt BR ts{$IBR {BtR $ Zk t Zts s9s s}s 8s $tsIBR }B sJZ jjBR JZ s? Zt tB Yst 8Z B et js tB% js 7Bk j k tIs >y V8 N tI d E(H I i${Ys I s Y RBt R B8s js j k tIs I j %s8}$ B IB ? stIBjs I Zts {$ s % BR$8$j$ ZI {$ t ? h{s =t {$ B $}B I As{ $s j %s8}$ $$R } B}Bt j sZ B R s js % 9 js {sZRs k j B $ t I js PZ 9s I j %s8}$ B NBR YZ8stBR $tP { sIBR 8Z t k ts{ t {Bt% $IBR t R R JZ stR? st Rst }s s RZAR$R $ w P { B I js tP 8 IsI {sZRsIs }B js As{ $sD k RBt } ? s{ ${s8 t $t8B sj R ? sR sjj? s I j 8s I j %s8}$ $R8B 8? sR } B}$B I j ? t B Pst ? sR ${B k I B js tB% js }jst s js RZ} %$% t{$s I Zt YB8A tB 8sj t Zts RB{$ IsI t js JZ $8} s js stB 8sj$IsI 7BA R R %s8}? ${BR % Rs s8A$? t js } j? {Zjs ] BtBR >d 1H eR ? R Zt BA` B - sB I$ts $B {BtR Z$IB t dxnx }B Zt sjJZ$8$R s JZ AZR{sAs Zt 8 {st$R8B JZ } B}B {$BtsR js %$Is ts NBR }$RBI$BR I js R $ I j %$R$? Bt ej $t8B sj >qY y88B sj d E T dH AsRsIs t js tB% js qY y88B sjR >d E1H I Fs8 R e pZtt R R$ ? Zst t Zt 8ZtIB IBtI sj ZtBR $tI$%$IZBR RBt $t8Zt R s js 8Z R s
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
@ N
3$ ; M 5i {Z Ist j hj8 Ns 8BR{s >qY 3jk d xMH2 _Z R sJZ? $ t t js ? }j${s P 8 t$tsU Zts R K tB s {Bt {sA 9s I s%$R}s VZtJZ sYB s tB R Zt 8sjB sIB -} $8 t B I stR8Z s{$? Bt I js 8s $s js {sZRs I js RZR $ Z{$? Bt I js {sA 9s I Zts } RBts }B js I Zt $tR { B R$tB js Z $j$9s{$? Bt I Zt } BIZ{ B I IZIBRs h{s{$s {BR8? ${s gWB Ysk JZ sAZRs I jBR } BIZ{ BR {BR8? ${BR k 8 tBR I sJZ jjBR {ZkB ZRB tB R ? s s st $9sIB * js } j? {Zjs qY GsR} GB8st >d x H
© Los autores, 2001; © Edicions UPC, 2001.
@ -
* $t Bt s e$tR $t
$t8Zt$IsI }Z I R stRP $Is s B BR 8 I$st stRPZR$Bt R Rst Z? t sR
NZ- V ts Zt$% RB
Ns tB% js {B s
>d xH I Fs%$ W I R{ $A Zt R JZ "%$% PZ s I tZ R B R}s{$B k
I tZ R B $ 8}B" k }B st B tB R ? s RB8 $IB s jsR $t -B sAj R j k R P? R${sR I tZ R B ]js B gsR ? {ZsjJZ$ s 7$t 8As B tB R 8? sR JZ Zt R$8}j 8B sj sZtJZ RB
R ? }BR IB I ZtBR }BI R {sR$ $tht$ BR } B}B {$BtsIBR }B js }BR R$? Bt I Zt P s 8 t B I g
sj$IsI } $8$ t$s
B I
$ st
N 8BRU "ej }BI BRB _st ? B{ s s isIt$s,? BR R sAs
sAZ $IB V8}j$s js $t8 tRs AZ AZ`s I RZ Zt$% RB } $%sIB {s {? s ks I sj${$ t k s8A$? t j YsR $sAs -} $8 t s t ? j {Bt sj s{$Bt R I jsR j k R PZtIs8 t sj R "
VZtJZ js R} st9s I %$Is s{ Zsj I YB8A R k 8Z` R t jsR B}Zj t sR RB{$ IsI R I j } $8 8ZtIB R R$ ? Zs t jBR x k M1 sK tBR R} { $%s8 t }s { s{ } sIB JZ } R sj t% ` {$8$ t B j B st$R8B YZ8stB }BI ? s 8Zk A$ t sj{st9s jBR dx( sK tBR R$t Zt I $B B $ }s sAj NBR s%st{ R t 8 I${$ts k A$BjB ? s {B8B jBR {B8 t sIBR t j {s}? ZjB { B
wRZR $ Z{$? Bt I jsR }s R I j B st$R8B 8? sR I R sR sIsR 8 `B {Bt Bj I js s{{$? Bt I jsR tP 8 IsI R $t8 tRsR }BR$A$j$IsI R I js $t t$ ? s t? ${s D } 8$ $ ? st R$t IZIs jB s Zts jBt %$IsI s} {$sAj _jsZR$Aj R }Z R js -$R t{$s PZ Z s I YZ8stBR {Zks R} st9s I %$Is RZ} {Bt YBj Z s jBR dd( sK tBR k {Zks s}s $ t{$s k Ps{Zj sI R }Z Ist R I ZtB I ${BR tB %s ? st jB JZ R Z s8 t tB R ? s j {sRBD IsI n( sK tBR wR$ jBR %BjZAj R 8BjI R R ? s js JZ 8}$ 9s s I$R8$tZ$ js P { $%$IsI I j PZt{$Bts8$ t B I jBR I$P t R B ? stBR I j {Z }B YZ8stB VR? jBR st s ? Bt${BR } B s Bt$R sR I
ej YB8A t j jsA $t B >qY st $t et ts I 7Ysb js t I {$I %$%$
Y s9 d E H I iBA 7$j% A RBt YZ8stBR I 8? sR I {$ t B % $t ${$t{B sK tBR JZ
zZ j s s s ZRsj? t >
s{B I R {Bt js 8BIs I RZ ? }B{s $ t t Zt sR} { B I YB8A R I tB 8? sR I {Zs t s s{, B YZR jsY d 1xH I p B
YsR s jBR n(( sK tBR gk R$t 8? sR JZ I R s jB jB {BtR$ Z t
_s s $ 8? sR sjj? s tB AsR s {Bt 8}js9s jsR }s R I P { ZBRsR I tZ R B {Z }B {B8B Y 8BR %$R B t j {s}? ZjB } { I t 7 $8}Bt t s{{$Bt R 8? sR I ? sR ${sR qsj R {B8B {s8A$s tZ R s t%Bj Z s {B }B sj {ZstIB ? R s Ys jj sIB s RZ P {Ys I {sIZ{$IsI k }BR B B {Z }B 8? sR `B% t k IB sIB {B8B Ys{ j YZ$I$9B - s R JZ YsA$ s t {Z }BR YZ8stBR I
B{Zj B
>qY <$II t d MMH
et js } j? {Zjs
3 `s{,
<$II tU
>d dH js s{{$? Bt stR{Z t Zt PZ Z B
{ {stB IBtI js t sI$t sIs {ZkBR {Z }BR R ? st I $B sIBR }B js IsI B js tP 8 IsI stRh RZ } RBtsj$IsI s {Z }BR `? B% t R RsjZIsAj R R {Z R sIBR I j }sRsIB _Z I }s{ s R {Bt Zts s9s - s R 8B $AZtIs js { R$? Bt I jBR {Z }BR t AZ tsR {BtI${$Bt R I jBR YZ8stBR Psjj {$IBR }s s JZ sJZ jjBR }Z Ist t{s ts R t jBR 8$R8BR {B8B RZ{ I t ZtB I jBR tZ %BR {s}? ZjBR I js R $ I qz
! BR j? 8$ R >qY !Z N$8$ RH
! R }Z I sAstIBts
}s s R$ 8} js s}s $ t{$s 8s $sj {Bt%$ $? tIBtBR t R R ? BR sj $ Zsj JZ jsR s%st9sIsR s9sR sj$ t? tsR }B sIB sR I js P s t$IsI {? BR8${s $t8Zt R sj I R sR JZ RZ}Bt %$%$ 7Bt $8s $ts $sR }BR$A$j$IsI R }s s %$ s R$t t { R$IsI I } BIZ{ BR {BR8? ${BR jB JZ j ? YZ8B $R s k R{ $ B Vj%s B I js y j R$s R t t{$sU "NBR YZ8stBR R s8BR Y {YBR I `$IBR I 8sjs {sj$IsI {Z }BR2" 5WB Yst BAR %sIB ZR I R JZ j AsK tB } BjBt sIB I js %$Is s Z s tZ R BR
z tI j sj8s sj I$sAjB {Z $ s j$-$ R 8? s ${BR }s s sj{st9s js $t8B sj$IsI B R$8}j 8 t I R s jB }Z I t R {Z RBR j ? $8BR }s s I Rs Bjjs Zts Y$R B $s I h{{$? Bt } B tB RBt {js B
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
d
R ? s jsR j? t sR JZ R$ Z t jsR $t% R $ s{$Bt R s{ Zsj R RBA {? B8B sRs j $tR st {$ B I js 8Z WB -$R Zt s{Z IB Zt? st$8 RBA js {Z R $? Bt I j }B JZ? t% ` { 8BR VZtJZ }s { JZ tB R Z ?t${s js {sZRs R$tB Zts {B8A$ts{$? Bt I I$P t R } B{ RBRU s{Z8Zjs{$? Bt sIZsj I B R t js {Bt $tZs }j${s{$? Bt I jsR 8Bj? {ZjsR I *WV 8Z I sj ZtBR $}BR I {? jZjsR JZ tB RBt 8}js9sIsR Zts % 9 j B st$R8B Ys sj{st9sIB js 8sIZ 9 k sZ B } BIZ{{$? Bt j$8$ sIs I j R B jsAB I R Z{ $%s I jBR sI${sj R j$A R 8Bj? {ZjsR 8Zk s{ $%sR I $%sIsR I j B-? tB } BIZ{$IBR t jsR 8$ B{BtI $sR =ts % 9 R jj Z s t tI js ts Z sj 9s I j t% ` {$8$ t B j }sRB R$ Z$ t {BtR$R $ ? s t I Rs Bjjs jBR } B{ RBR }s s s Is jB ]ZsjJZ$ s }BI ? s } tRs JZ R$ sYB s tB R }Z I RZ{$ s s jBR 8Z BR sj % 9 t Zt PZ Z B R ? s {tBj? B ${s8 t }BR$Aj VR? JZ 5}B JZ? tB RB8 R s sj ? Zt } B{ RB I 8st t$8$ t B I j {Z }B I R}Z? R I js 8Z s js R} s I JZ jj Z Rs }BR$A$j$IsI2 wjs { $B t$s }B ` 8}jB z {s}? ZjB ED 3 st{$R s{Bt ZtB I jBR PZtIsIB R I js {$ t{$s 8BI ts k sZ B I js Z B}? s {$ t ? h{s Ns tZ %s V j? st $Is >dE1 H wIBtI I${YB R s I }sRB }Z I t t{Bt s R sj ZtBR 8 I$BR {sR BR }s s } BjBt s js %$Is {B8BU }Bj%B I 8s s $ sR I$RZ j B t j$8? Bt B `Z B I I$s8st RD }Z I R {BtR$I sIB s8A$? t {B8B ZtB I jBR } $8 BR 8? s $ R I jsR YsA$ Zsj R ? {t${sR I } R %s{$? Bt I sj$8 t BR 8 I$st {Bt js{$? Bt =t I? s JZ 8} 9? B s t %s j RZ $ $? B js $I s I Z $j$9s js t$ % }s s {BtR %s jBR {Z }BR k } R %s jBR I js {B Z}{$? Bt <B8A {Bt Zt $t ? R I R8 RZ sIB }B js -} $8 t s{$? Bt {$ t ? h{s {B8} ? B Zts sjj$ts Y$9B sjj? 8$R8B j -} $8 t B {Bt j st$8sj et }sjsA sR RZksR " I$B -{ j t R RZj sIBR } B s 8? 8 I$B Zt s sJZ I BR " Z $? B I A BtJZ$ $R }B{BR I? sR I R}Z? R 7$ jsR ? {t${sR I } R %s{$? Bt AsRsIsR t j P ? B }s { t R %$ }B j 8B8 t B R? BjB }s s {BtR %s jBR sj$8 t BR t Bt{ R I A 8BR B $ t s js A? ZRJZ Is I js $t8B sj$IsI Ys{$s B BR I B BR qsj % 9 Ysks JZ AZR{s }s s` R $ tB BR $ sR Bj%$IsIsR }B j $ 8}B wtZt{s 8 `B I${YBD ]B8B j %sjj I 7Yst $Tjs h{ ${$B }s s` 8}js9sIB t jsR $tY? BR}$ sR {Z8A R 8Bt sK tBRsR I j q? A IBtI ZtsR -{ }{$Btsj R {BtI${$Bt R {j$8s Bj? B ${sR k j s$Rjs8$ t B I j 8ZtIB - $B RBt jBR $t I$ t R I AsR JZ } 8$ t s RZR YsA$ st R sj{st9s Zts -{ }{$Btsj jBt %$IsI ! sj 8 tBR sR? R js s t js } j? {Zjs <B $9Bt R } I$IBR >NBR <B $9Bt d nnH =tB tB RsA s {$ t{$s {$ s R$ sj {BRs PZt{$Bts ? s {B8B t js } j? {Zjs sZtJZ A$ t R % IsI JZ st B tZ R B {Z }B {B8B tZ R s 8 t RB8 $IBR sj {Bt $tZB I R sR {B $I$stB s sI { ? st Zts R st{$s t st R$t Zjs jZ s V}s t 8 t js PB 8s 8? sR R t{$jjs I RB s js 8Z R t {BtB{$8$ t B I {Z? stIB k I? BtI ? R s %s s s{Bt { k R$8}j 8 t I {$I$ tB R s sjj? sR s }s s jjB I$R}Bt I Zt I$R}BR$ $%B {B8B j $t% t B JZ s}s { t js } j? {Zjs ej 8ZtIB 8Ajs ? s >N 8BtI 8Aj s d n H B t j js B Ns j? t s I js %$Is >N$P TN$t d n H I iBA < $tj $t {s}s9 I } I {$ j 8B8 t B -s{ B I js 8Z I {sIs } RBts eR B R s8A$? t jB JZ ts s Fs{, {* %$ t RZ -{ j t tB% js {B s NBR %$s` BR I j $ 8}B tZt{s 8Z t >q$8 q s% j R W % *$ d 1H ]js B JZ R B Z ?j $8B {B8}B s js }BR$A$j$IsI I %$s`s }B j $ 8}B k RB R ks Ys $ts ZjB ED I B B {BR sj sj {B8B % 8BR 8? sR sI jst w]s}?
i { } ? s{ZjBR I js {? jZjs IBtI R t s js t ? s t { Rs $s }s s js 8skB ? s I jsR s{ $%$IsI R { jZjs R
© Los autores, 2001; © Edicions UPC, 2001.
d M
* $t Bt s e$tR $t
3$ ; VAZ $8$ t B s}s ? s k I R$I$s RBt jBR R sIBR st? 8${BR I Zt R JZ I$R}Bt I BIB j $ 8}B I j 8ZtIB }s s Ys{ jB JZ I R s
* BIsR PB 8sR Zt IBt st } {$sIB {B8B js $t8B sj$IsI }s { JZ s{s s {$ BR $t{BtT % t$ t R =t $t Bj sAj YsR ? B Zt $tht$ B sAZ $8$ t B k Zts - 8s 8 jst{Bj? s RBt jBR R t $8$ t BR JZ 8As st s jBR } RBts` R I js h{{$? Bt JZ B9st I js $t8B sj$IsI P? R${s w{B8B j {BtI * ? s{Zjs B jBR R}sIs{Y$t R jZ{YsIB R I js R $ I hj8 R NBR $t8B sj RD P Z B I js s8s s } R} { $%s {Bt JZ jBR R{ $ B R k Z$Bt$R sR I {$ t{$s h{{$? Bt Yst {BtT M Bj${s RBj IsI I Zt R $t8B sj R s8A$? t }s t t js R$I sIB js $t8B sj$IsI Ns 8 jst{? } j? {Zjs ej stR$s >qY <Zt d MnH k t js tB% js q? Z j $t8B sj >qY$R y88B sj d ExH I iB js9tk et R s Z ?j $8s Zt YZ8stB $t8B sj {Zks s s {BtR$R t RZ} %$Rs k } R T %s jBR R BR s JZ Bj? B ${BR I Zts q$ s I %sR sIs I A I P tI s Zt t%$sIB sj$ t? ts t RZ } $}jB R I ZtBR R R 8Z st R P Z B I js sI$s{ $%$IsI JZ { st h Z sR 8$ Bj? B ${sR {j? sR${sR Vj 8s t I j R sIB st? 8${B } RBtsj jBR } BAj 8sR RZR{$ sIBR }B js -$R t{$s I $tI$T %$IZBR tB ks $t8B sj R R$tB jBt %BR }s s Zts RB{$ IsI RBt 8? Zj $}j RU -}stR$? Bt I 8B ? sh{s }BAjs{$? Bt t% ` {$Is { Ns tB% js qY ytt <BZR >dMMMH I Gsj Rst R Zts I$R B}? s JZ }jst s j R st{s8$ t B RB{$sj JZ {Btjj %s js -$R t{$s I js {tBjB ? s JZ } B}B {$Bts js $t8B sj$IsIU js P sR 8sK tsts 8}$ 9B I `s I t R t $IB {ZstIB j t? Z8 B I 8sK tstsR qs8A$? t }s { R ? R s js %$R$? Bt JZ s{B8}sK ts sj 8s I js $t8B sj$IsI t tB% jsR {js% I js j$ s Z s Zt$% Rsj {B8B qBIBR jBR YB8A R RBt 8B sj R >qBZR j R YB8 R RBt 8B jR d ;EH I Z`${s N? s$t 9 IBtI R -s8$ts js t { R$IsI s 7$8Bt I sZ%B$ B B8s 9B >d E1H I stZ j ? js }BR I s{sAs tP t ? stIBR s js Ps sj$IsI I js 8Z et js {BtB{$Is Ns $t% t{$? Bt I B j >d ;(H I VIBjPB $Bk ]sRs R js A? ZRJZ Is I js $t8B sj$IsI }B }s I j } B s Bt$R s {Zj8$ts {Bt Zt $t% t B JZ $ t RZ PZtIs8 t B t jBR } $t{$}$BR PB B ? sh{BR et Ns Y$R B $s I js t$IsI >d xnH FB NZ$R B R 4 -$Bts RBA js t$IsI js $t8B sj$IsI k j 8$ B I j tB B tB M
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
@
}s s Zt R $t8B sj R $tht$ B 5_s s JZ? RPB 9s R t Ys{ sj B }Z R R$ I BIsR PB 8sR j $ 8}B `Z s s tZ R B Ps%B 2 VI 8? sR t Zts Y$}B ? ${s RB{$ IsI t js JZ st R? BjB sj ZtsR sR Ps{ $Aj tB sAj jBt %$IsID 5JZ$? t } RBtsR }Z I t sj{st9s js $t8B sj$IsI wB Zts 8? s{{ I ? s s R {BI${$sIB R s ZR2 57Bjs8 t js t t{st sIB s {B8B } B}Bt t s , ]j$P Bt k 3 st, i$j k t qY 3B % s{Y$t >d xMH2 NB 8? sR } BAsAj R JZ R? BjB JZ$ t I$R}Bt s I I$t B }BI ? s A t h{$s R FB <sjI 8st t js tB% js ]B8} sIB R I $ 8}B > Zk$t q$8 d M H }jst s Zts RB{$ IsI I j PZ Z B IBtI js ? {t${s } 8$ js t s{$? Bt I jBR {Z }BR YZ8stBR 7$t 8As B }s s t s{{ RB s js 8$R8s Ysk JZ }BR sj 8 tBR Zt 8$jj? Bt I I? Bjs R k { I BIB j }s $8Bt$B } RBtsj s js PZtIs{$? Bt R}BtRsAj VR? JZ }s s {sIs tZ %s t s{$? Bt Ysk JZ YsA s8sRsIB Zts tZ %s PB Zts g Bt$ s 8st s I PB8 t s j {s}$ sj$R8B Rsj%s` qs8A$? t $tJZ$ st R RZj st s R R} { B jsR } B}Z R sR RZ $IsR }s s RB{$ IsI R PZ Z sR t } j? {ZjsR {B8B Ns PZ s I NB st >NB st:R iZt d EH w{Bt% $Is {Bt }BR $B $IsI t R $ I qzD IBtI sj sj{st9s jBR n( sK tBR jBR $tI$%$IZBR I A t 8B $ }s s I `s }sRB s B BR 8? sR st }s sIB t jjs tZ R BR BA tst R }s s s{sAs {Bt `? B% t R =ts I ? sR ${s RBjZ{$? Bt w5YsA ? j } BAj 8s I jsR PZ Z sR } tR$Bt R2D ! j hj8 ]ZstIB j I R $tB tBR sj{st{ >7Bkj t p t d nH w% R$? Bt AsRsIs sZtJZ sj$ sIs I {Bt t$IB { ? ${B t js tB% js g<s st R$ $B Ys st R$ $B > s, iBB8 s, iBB8 d EEH I <s k <s $RBtD IBtI }s s RBj% j } BAj 8s I js RZ} }BAjs{$? Bt -$R js Z stsR$s {j? t${s PB 9BRs qs8A$? t t j js B Ns $Is >pB$t d dH I iBA 7$j% A R sAB Is j 8s I js I Rs}s ${$? Bt %BjZt s $s k {BtR{$ t et js RB{$ IsI I j sK tB 1( x j RZ${$I$B R ? s $tR $ Z{$Btsj$9sIB Ns hjBRBP? s $8} st RZ8$Is t js P sR U "js Z Is $ t JZ $ s " $8} j s jsR } RBtsR I IsI s%st9sIs s sAstIBts j 8ZtIB }s s I `s R$ $B s jBR JZ R} st Zt jZ s t ? j et jsR I tB8$tsIsR ]sRsR I I R} I$Is k {Bt js {BjsAB s{$? Bt I Zt Z? s } RBtsj R skZIs s jsR } RBtsR s s{ } s j {BtB{$8$ t B I JZ R Ys {Z8}j$IB RZ %$Is Ns }s $Is B js $Is {Bt JZ ZP 8? R ${s8 t R I R$ ts R s{ B }BR B R? BjB $ t jZ s {ZstIB R Ys jj sIB sj {Bt% t{$8$ t B I JZ tB JZ Is tsIs JZ Is j s js %$Is t$ s8}B{B tsIs JZ R} s I jjs
$ {sA 9s R %s BIB R {BtPZRB }s s 8? $ t } tRsIB sj % 9 tB %sj s js } ts {BtR %s tZ R s t%Bj Z s {B }B sj R$tB jsR -} $ tT {$sR jBR {Z IBR k jBR } tRs8$ t BR s{Z8ZjsIBR s jB js B I js %$Is k sj8s{ tsIBR t sj ? Zt jZ s I j { A B 5WB R Zts PB 8s I $t8B sj$IsI js sj{st9sIs }B jsR BA sR {j? sR${sR I js j$ s Z s j s B js {$ t{$s k }B tI RZR sZ B R2 et js RB{$ IsI I *$sR}s JZ s}s { t js tB% js Ns {$ZIsI k jsR R jjsR >qY ]$ k stI Y 7 s R d xEH I V YZ ] ]js , js YZ8st$IsI sj{st9s js $t8B sj$IsI s AsR I s {Y$%s jBR {Z IBR I j { A B t 8? sJZ$tsR k RZR $ Z$ j {Z }B Vj B R$8$js {B8B Y 8BR %$R B s jB JZ Ys{ t jsR } RBtsR }ZI$ t R I j hj8 3 `s{, 5_ B {? B8B sj8s{ ts sj $t t %BjZ8 t I Is BR2 V jB js B I js Y$R B $s I js YZ8st$IsI R Yst $IB } P {{$BtstIB jBR 8? BIBR }s s sj8s{ ts k } B{ Rs js $tPB 8s{$? Bt * RI jsR 8B sR $t{$R$Bt R t s {$jjs I jsR sAj$jjsR RZ8 $sR s js $8} t s I pZ tA Y 8BR jj sIB s jsR s{ Zsj R ? {t${sR JZ } 8$ t Zs Is k T {Z} s js $tPB 8s{$? Bt t RB}B R 8s t? ${BR A$ t R s t {$t sR {B8B {sR R k %? I BR B t
© Los autores, 2001; © Edicions UPC, 2001.
* $t Bt s e$tR $t
PB 8s I I$RJZ R 4 -$Aj R k I$R{BR IZ BR I jBR B I tsIB R et js 8BI ts {$ t{$s h{{$? Bt jBR 8s $sj R 8s t? ${BR Yst R$IB {B8}sK t BR $tR }s sAj R I jBR $t ? }$IBR sR BtsZ sR t sR sjj? sD Vj 8s t I j jsR I$P? {$j R k s $ R sIsR 8$R$Bt R s jB js B k st{YB I js psjs-$s wk 8? {sj9sIB 8s t? ${B {B8B j JZ s}s { t j hj8
]Bt I R $tB s js NZts >* R $ts $Bt BBt
d x(H Z $j$9sIB {B8B 8 I$B }s s % t{ js $t s%$I 9 } B}${$stIB Zts sIY t{$s {Bt j {sR{B 8 ? sj${B I js ts% R BR 8s $sj R {BtPB 8st jsR 8 8B $sR I jBR ZA? {ZBR B I tsIB R et BIs ts% $t R js JZ R } {$ tB }Z I Psj s j B I tsIB I s AB IB j {Zsj R t{s s }B jB t sj I I$ $ $ jsR {B8}j `sR 8st$BA sR JZ {Btjj %s js ts% s{$? Bt R}s{$sj =ts
} R t{$s JZ ks } Bt B }BI 8BR s}j${s tB R? BjB s js h{{$? Bt sj R j sIB I } t s{$? Bt
W!zV] I js } j? {Zjs pB >d x;H ]BjBRRZR j B T pZs I$st RZ YB8? BjB B RB%$? ${B I j hj8 ]BjBRRZR j } Bk { B } BY$A$IB >]BjBRRZR Y 3B A$t _ B` { d E H j }s stB${B <VN ((( I 1((d Zts BI$R s I j R}s{$B >1((dU V 7}s{ !IkRR k d EMH B j B I tsIB 8ZtI$sj I iBjj Asjj >d xH =NqyzV] js {B8}Z sIB s JZ s}s { t js BR I yRss{ VR$8B% {B8B z$Is k $ 8}BR I Zj $%s{ >qY N$P stI q$8 R BP =NqyzV] d xH k j j$A$I$tBRB _ B ZR yz I et tI B 8 {? st${B >* 8Bt 7 I d H O t }jst R ZtI? Bt sZtJZ j %st sI } j? {ZjsR k tB% jsR 7Bt ` 8}jBR {? j A RU I tsIB JZ {Bt Bjs jBR 8$R$j R I P tR$%BR tB s8 ${stBR k j B I tsIB I s AB IB I j WBR B8B js ts% R js IBtI j {$? t 8As {sIB B st$R8B sj$ t? ts Ys{ I jsR RZksR I
JZ R BR I$R}BR$ $%BR Yst sj{st9sIB NBR B I tsIB R Yst B{Z}sIB Zt jZ s R js t sj ZtsR
Vj$ t j B{ s%B }sRs` B >Vj$ t d H
et BA sR 8? sR {$ t R
jsR {Bt -$Bt R t B I tsIB R 8}$ 9st s R st $8}B st R {B8B jBR } B}$BR B I tsIB R eR j {sRB I
Ysk t js I sj? s{ ${s I js tB% js
Fst js $t j$ t{$s ts{$Is I jsR {Bt -$Bt R I jBR 8$jjs R I B I tsIB R JZ ej `Z B I etI >etI :R ps8 d MxH k I G!_i FZ BR I Z s >Gs ps8 R d MnH
j R$R 8s $tPB 8? s ${B I I P tRs tZ{j s tB s8 ${stB $t{s}s9 I I$R $t Z$ t `Z B R$8ZjsIB k sj$IsI I js } j? {Zjs
i RZj s }s sI? B`${B JZ t Zt $t t B }B - s}Bjs js {tBjB ? s I j 8B8 t B s Zts ? }B{s PZ Z s tBR t{Bt 8BR s 8 tZIB st Pst ? sR ${BR R$R 8sR I {B8Zt${s{$? Bt I stR}B { JZ {Btjj %st j ZRB I Zts {tBjB ? s BARBj s wsj 8 tBR I RI tZ R s } R} { $%s s{ ZsjD 7$ %st s 8BIB I ` 8}jB js Z $j$9s{$? Bt I s ` sR } PB sIsR t jBR B I tsIB R
I }BI BRsR {B }B s{$Bt R 8Zj $ts{$Btsj R {B8B js
]B }B s $Bt $I sIs }B yRss{ VR$8B% k JZ s}s { t 8Z{YsR I RZR BA sR RBA BAB R {B8B N ttk >d x H B t js {BjBt$s YZ8sts t js NZts t }j tB R$ jB yy I ]js B I q$ s >es Yj$ Y d H I V YZ ] ]js , V tsI$ }Z I R{s}? s R j R$t IZIs jB I$P? {$j k
=t$ I 7 s R iBAB R stI {Yst${sj t
_jst s } BY$A$IB >3B A$II t _jst d xEH JZ R$ ? Zst j sjZt$9s` Ys{$s j sK tB 1( ( B t js BR {B BR {B8B Vj ? Zt I? s >7B8 Isk d xEH I yRss{ VR$8B% IBtI s}s { t t } j? {ZjsR {B8B R YsAjs I Zt PZ Z B t j JZ js RB{$ IsI Ys Bj%$IsIB jB JZ R$ t$h{st }sjsA sR {B8B j B R{ $A$ k IBtI {ZsjJZ$ s{ $%$IsI $t%BjZ{ s j ZRB I B I tsIB R s{ $%sIBR {Bt js %B9 JZ PZt{$Btst s? Zt {Bt {$t sR 8s t? ${sR WB sAj 8 t ? Bt B R j ZRB I jBR B I tsIB R JZ s}s { t t jBR js BR I js R $
s $ R sIB JZ }Z I jj s s R {ZsjJZ$ $t t B I - s}Bjs{$? Bt _ I${{$Bt R JZ$%B{sIsR
FBt R j YB8A R js >7 s 8st FBt R d xnH I iBA V
< $tj $t IBtI jBR {$ t ? h{BR Z $j$9st sAjsR I jB s $ 8BR }s s } B{ Rs js $tPB 8s{$? Bt gst R I RZ8$t$R s js s jBR B I tsIB R
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
@
ej $ 8B I 8$t$s Z $9s{$? Bt { {$ t I jBR {$ {Z$ BR k I jBR {B8}Bt t R j { ? Bt${BR JZ {BtRT $ Zk t jBR B I tsIB R }s { YsA {B $IB s8A$? t I R} % t$IBR s R{ $ B R k Z$Bt$R sR wtB R? BjB s jjBR R$tB s {ZsjJZ$ s R$ Y 8BR I R R$t{ BRD Ns 8skB ? s I jBR B I tsIB R JZ s}s { t t js h{{$? Bt RBt 8? sJZ$tsR tB 8 R {Zks }B t{$s R ? s I$ { s8 t js{$BtsIs {Bt j s8sK tB w]ZsI B ; dD Ns {BtR Z{{$? Bt I j } $8 B I tsIB t jBR sK tBR ;( j %BjZ8$tBRB eWyV] tB I `sAs } Rs $s js %BjZ{$? Bt R Z$Is Ys{$s js IZ{{$? Bt I s8sK tB =ts s s -{ }{$? Bt R j js B qY s $st 7YB} >d x H I <Bbs I 3sR IBtI R I R{ $A Zt B I tsIB I PB 8s {? ZA${s I st R? BjB dx {8 Vj B JZ jBR s{ Zsj R B I tsIB R }B ? s $j R R ? st } R BR s RZ} s V 8 tZIB t js h{{$? Bt s8}B{B R Ys RsA$IB Rs{s } B% {YB I jsR % t s`sR JZ jBR B I tsIB R }BR t RBA jBR YZ8stBR s js YB s I sj$9s I 8$tsIsR s sR Ns s}$I 9 I {? sj{ZjB k RZ $tPsj$A$j$IsI tB }s { t R RZh{$ t R s $AZ BR }s s JZ 8Z{YsR Z $ts $sR s sR I js h{{$? Bt R sAstIBt t s 8stBR I ? R BR }B jB I 8? sR {Z $BRBR t R {Bt JZ$ t R R s8BR JZ ? s8BRjB B tB {BtI tsIBR s {Bt%$%$ <Bk t I? s jBR B I tsIB R 8? sR ? s}$IBR }Z I t P { Zs A$jjBt R I B} s{$Bt R }B R ZtIB =t 8BI R B B I tsIB _] I RBA 8 Rs }Z I sj$9s {sIs R ZtIB %s $BR 8$jjBt R I B} s{$Bt R =ts s s }s s js JZ Zt { A B YZ8stB {s}s9 I sj$9s ZtB B s jB RZ8B %s $BR {? sj{ZjBR }B R ZtIB t { R$ s ? s sj I IB I Zt sK tB I {$ I j PZ Z B2D g sAs`stIB 1; YB sR IZ st nEx I? sR ]Bt R }B t{$sj s{ Zsj w5JZ? RZj s {Zst B 8 tBR -sR} st BAR %s {? B8B t }j tB P s B I js As sjjs R}s{$sj jsR $}Zjs{$Bt R }$ I t R ZtIBR %$ sj R t {$A$ I jBR Bh{$sj R B ? I t R I j $}BU "]Bt { t j {s8}B I 4 { B 8st t st sA$ B j R { B I } Bs k jst{ t j B } IB I PB Bt R" 5WB RZj s ? s 8? sR h{$ t I `s t 8stBR I j B I tsIB I Z tB js sR? } ${s ]B8}Z sIB s I js ts% et } $R }B ` 8}jB js s{{$? Bt Z s I js ts% 2 5_B JZ? tB { I j {Bt Bj I js 8$R8s sj B I tsIB 2 ]js B JZ t Bt{ R sj {s}$ ? st I j { Z{ B R js }B{s {BRs j JZ Is ? s }B Ys{ O tB I$ s8BR s js $}Zjs{$? Bt JZ RZj s ? s I j BIB $tt { Rs $s gVI$? BR R $sj } j? {Zjs B tB% js NBR s%st{ R {$ t ? h{BR k ? {t${BR s{s {$IBR IZ st jBR Z ?j $8BR I { t$BR Yst } 8$ $IB Zs Is - s k } B{ Rs {sIs % 9 8? sR $tPB 8s{$? Bt Ns %BjZ{$? Bt I js {s}s{$IsI I sj8s{ ts8$ t B I js $tPB 8s{$? Bt Ys R$IB st R} { s{Zjs {B8B js 8$t$s Z $9s{$? Bt k j sZ8 t B I jsR } R sT {$Bt R $ t sR JZ jBR } ? s{ ${s8 t BARBj BR I$RJZ R I x }Zj sIsR } 8$ t sj8s{ ts nE( ,$jBAk R@ jBR I n, x }Zj sIsR }BR t Zts {s}s{$IsI ; % { R RZ} $B wd, ; 8 sAk RD@@ 7$t 8As B js {st $IsI I $tPB 8s{$? Bt JZ }Z I sj8s{ ts R t RB}B 8s t? ${B }s { R s jj stIB s jBR j? 8$ R ? B ${BR * sj PB 8s JZ R %$ t t I Rs BjjstIB {tBjB ? sR sjT ts $%sR JZ $t t st }sj$s jsR t { R$IsI R I sZ8 t B I js {s}s{$IsI I sj8s{ ts8$ t B eR ? st ks s js B I t I j I? s jBR I$R{BR B ?} ${BR w t jsR 8BIsj$IsI R I I$R{BR {B8}s{ BR k I$R{BR j? sR D JZ 8}$ 9st s $8}Bt R RBA jBR RB}B R 8s t? ${BR {B8B R$R 8sR }s s j sj8sT Ns {s}s{$IsI I {? sj{ZjB I Zt B I tsIB R 8$I t js Zt$IsI I tB8$tsIs 4B} wI j $t j? R 4Bs $t B} s $Bt B} s{$? Bt 4B st D d A$jj? Bt I B} s{$Bt R }B R ZtIB JZ$%sj t s d s4B} @ =t Ak {B R}BtI s Zts R {Z t{$s I ZtBR k { BR I M I? $ BR {sIs ZtB I jBR {Zsj R R I tB8$ts A$ =t 8 sAk JZ$%sj s d 8$jj? Bt I Ak R k d $ sAk s 8$j 8$jjBt R @@ et js s{ Zsj$IsI -$R t ks I$RJZ R I j 8$R8B s8sK tB {s}s{ R I sj8s{ ts YsR s d1( 8 sAk R
© Los autores, 2001; © Edicions UPC, 2001.
* $t Bt s e$tR $t
]ZsI B ; d Vj ZtsR {BRsR JZ R? BjB jBR B I tsIB R I js h{{$? Bt }Z I t Ys{ NBR B I tsIB R RBt {s}s{ R I sj$9s 8Z{YsR {BRsR w Zs Is k {Z} s $tPB 8s{$? Bt R{ $A$ $8} $8$ {BtB{ js %B9 {Bt { s R {Bt B BR B I tsIB R { D sZtJZ RZR s}s ${$Bt R t j {$t BAj$ st s j${ t{$sR JZ tB }Z I t }B 8 tBR JZ Ys{ RBt ? s jsR } RBtsR JZ j$I$st {Bt jBR 8$R8BR t RZ sAs`B {B $I$stB VY? %st sj ZtsR I jsR s sR JZ sj ZtBR Z$Bt$R sR }B{B R{ Z}ZjBRBR j R Yst sR$ tsIBU s R$ 8} T ]ZstIB sj Z$ t } R$Bts jsR {jsR tZt{s R {B8 t Y B R w5 R ? {Bt { sIB j {B { B I - BR2D T ]sIs % 9 JZ s}s { Zt {s ? s{ t js }st sjjs I Zt B I tsIB RZ $8s t R st A $jjst JZ R % 4 `sIB t js {s s I j ZRZs $B z? sR 1((d Zts BI$R s Bt I As`B t$% j JZ I j R}s{$B B Vj$ t j B{ s%B }sRs` B w57 s s I js sI$s{$? 8$ BIs }st sjjs2D T NsR }st sjjsR -}jB st st R I JZ jB Ys s j I$h{$B B $tR sjs{$? Bt wgJZ %$%s j R} { ? s{ZjB D T 7 }Z I $t BIZ{$ Zt %$ ZR $tPB 8? s ${B t Zt B I tsIB R$t 8? sR JZ R{ $A$ stR jsR } j? {ZjsR 3B sj 9s $tP tsj js R t t{$s =}jBsI z$ ZR w]s s %$ ZRD z? >3B RR d 1H ytI } tI t{ *sk >d EH T q {j stIB R$8}j 8 t js $tR Z{{$? Bt V{{ RB s jBR h{Y BR R { BR R $ t s{{ RB s js $tPB 8s{$? Bt R { s I R sIs z? stR sj ZtBR }$RBI$BR I js R $ e-} I$ t >qY 3$j R d nTH T _s s Zt }$ s s $tPB 8? s ${B R$ 8} R }BR$Aj t s t Zt B I tsIB k sI$%$ts js {js% I t sIs I R}Z? R I Zt }s I $t t BR wtB R s JZ j R} { sIB R {stR I R} s D T qBIBR jBR B I tsIB R R ? st {Bt { sIBR I PB 8s } 8st t 7 }Z I s{{ I s js $tPB 8s{$? Bt I j B I tsIB I {ZsjJZ$ %$jjstB sZtJZ R t{Z t s}s sIB T NBR I$RJZ R PZt{$Btst t {ZsjJZ$ B I tsIB $tI } tI$ t 8 t I j RBP bs k R$R 8s B} s $%B JZ ? R Z $j${ T =ts js I B BU {Zst B 8skB R s j t$% j {tBj? B ${B I j JZ$}B st BR 8? sR s{ZjB D AB Bt R k jZ{ {$ sR tI ? s wgJZ R$ s j R} { ? T 7 }Z I %$ s j 8 tRs` _ 8$RR$Bt * t$ I w_ 8$RB I t sIBD R$t 8? sR JZ Z $j$9s js $tR Z{{$? Bt !% $I wyt%sj$Is D z? sR js } j? {Zjs * 8Bj$ $Bt st >d nH T =t B I tsIB }Z I {Bt { s R {Bt {ZsjJZ$ B B R$t t t {Z t s {Z? sj R RZ } B{ I t{$s B 8s {s B js sjs-$s IBtI Ys R$IB PsA ${sIB z? sR ytI } tI t{ *sk s t R T ]ZsjJZ$ B I tsIB }B } JZ K tB JZ R s R {s}s9 I sj$9s s sR w$8? $I$8 tR$Btsj R t 8B%$8$ t B { D JZ R? BjB jBR stI R B I tsIB R RBt {sT }s{ R I P { Zs wR$ RBt B I tsIB R I j PZ Z B %sj D T Ns 8skB ? s I jsR % { R jBR {jsIBR JZ s}s { t tB $ t t t$t Zts $JZ s ej Z ?t${B AB ? Bt {js s8 t $I t $h{sIB R j I VZ BI R Z{{$? Bt
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
1(n
T ]ZstIB sR Zts }s sIs }B ` 8}jB s {sZRs I Zt {B I j RZ8$t$R B j? { ${B R $t${$s j R$R 8s BIB PZt{$Bts {B { s8 t k R B ts t Zt $tR st s js R$ Zs{$? Bt I }s $Is z? sR
_s JZ FZ ? sR${B
T Ns ts% s{$? Bt }B yt t R$ 8} jj %s s AZ t }Z BU tB $8}B s {Zst %s s R s js }sjsA s AZR{sIs R$ 8} R t{Z t s sj B _B ` 8}jB t js } j? {Zjs
y8}BRR$Aj >d EH j } B s Bt$R s sj$9s Zts A? ZRJZ Is $t BIZ{$ tIB }sjsA sR {B8B hj wh{Y BD k {B8}Z wB I tsIB D k j ts% sIB I yt t t{Z t s ]B8B {B8} BAs{$? Bt Y 8BR sj$9sIB R 8$R8B -} $8 t B k
$RR$BtU
gn t sIsR
tZ R B ts% sIB I yt t Ys t{Bt sIB gEdM ;1 t sIsR t j } $8 {sRB k d!d (!d t j R ZtIB
eR s js{$? Bt tB -YsZR $%s R ? s sIs} sIs I js $tPB 8s{$? Bt BA t$Is I p B& < sPB I s s%? R I
yt t
{ ts8$ t B I stI R %Bj? Z8 t R I $tPB 8s{$? Bt I I$R{BR B ?} ${BR *z* wR$ jsR I
et Zt I$R{B {B8}s{ B w]*Ti! D }Z I
sj8s{ ts R j JZ$%sj t s 8? sR I g;Mx I$RJZ R wZtBR EM( 8 sAk RD Ns tZ %s t s{$? Bt
I$R{B % R? s $j I$ $ sjD } 8$ t ks js sAs{$? Bt I YsR s d
$ sAk R t Zt s8sK tB $ Zsj sj I j ]* VR? 8$ t sR JZ }s s Zs Is j - B I Zt j$A B I PB 8s B 8 I$stB R RZh{$ t Zt I$RJZ }BI 8BR t BIB j {Bt t$IB I Zts t{${jB} T I$s {B8B js s t R RBt$IB eR}sRs B js $ ? st${s t Zt }s I I$R{BR I PB 8s B *z* w{Bt $8? k Zt s{{ RB s}$I? R$8B s BIs js $tPB 8s{$? BtD ]st $IsI R JZ }Z I t }s { I RB A$ sIsR 8? s-$8 {ZstIB R s %BjZ{$? Bt R Ys {BtR Z$IB t 8Zk }B{BR sK tBR
@ _ R s jjB sj8s{ ts
t Zt RB}B 8s t? ${B j {? BI$ B t? ${B YZ8stB B js }BR${$? Bt I BIsR jsR {? jZjsR JZ {BtT PB 8st tZ R B B st$R8B }B ` 8}jB RBt s sR {BjBRsj R w]s}? ZjB ED et Zts R{ ts I js } j? {Zjs
_s JZ FZ ? sR${B R 8Z R s Zt P s 8 t B I *WV I ZtBR d ((( Ak R RBA Zts
}st sjjs I B I tsIB NBR {$ t ? h{BR {B8 t st JZ 8$ stIB Zts % 9 }B R ZtIB Zts }stT sjjs {B8B sJZ jjs IZ st B{YB YB sR sj I? s R s Is ? st }B jB 8 tBR IBR sK tBR t {B8}j s BIs js R {Z t{$s ]B8 t s $B AsR st s{ sIB IsIB JZ Zts {sI ts I *WV B{Z}s ZtBR 1( $ sAk R
_s sj jsR s js %BjZ{$? Bt {tBj? B ${s ? {t${sR 8$- sR {B8B js B} BT8s t? ${s s%st9sIsR t PB 8s I B I tsIB R B ?} ${BR B s? Zt }B jj s {B8B jBR B I tsIB R {Z? st ${BR 8}$ 9st s R Z $j$9sIsR t jBR s Z8 t BR I {$ t{$s h{{$? Bt 8BI tBR
q ,U js tZ %s t s{$? Bt >7 s q ,U
7 $ R I j %$R$? Bt {B8B
7 s
Y W - p t s $Bt d M T 1H $t BIZ{ t j ZRB I B T
I tsIB R JZ B} st {Bt 8 8B $sR B ?} ${sR ejjB Ys{ }BR$Aj j sj8s{ ts8$ t B k } B{ RsIB I %Bj? Z8 t R I $tPB 8s{$? Bt 8? sR stI R }s s Is {Z8}j$Is R}Z R s s BIsR jsR 8$R$Bt R t{B8 tIsIsR sj B I tsIB { t sjU j {Bt Bj sARBjZ B I js ts% B jsR $8} R$Btst R R$8ZT
et {B8}s s{$? Bt j { A B YZ8stB {Bt $ t sj I IB I d(d( t Z BtsR jsR {? jZjsR j 8 t sj R A? sR${sR I j R$R 8s t %$BRB t{s sIsR I stR8$ $ js $tPB 8s{$? Bt 8 I$st $8}ZjRBR j? { ${BR *sIB JZ {sIs Zts I jjsR }Z I {Bt { s R {Bt B sR d ((( Zts R $8s{$? Bt ZI$8 t s $s I js {s}s{$IsI I sj8s{ ts8$ t B I js $tPB 8s{$? Bt I j { A B s B`s Zt %sjB I d(d( d(n ) d(dn A$ R I $tPB 8s{$? Bt R I {$ ZtBR d( $ sAk R @
© Los autores, 2001; © Edicions UPC, 2001.
1(;
* $t Bt s e$tR $t YBjB sAj B {ZABR I 8 8B $s
js{$Bt R t js Rsjs I j
NBR
s}s { t s 8 tZIB t jsR A$Aj$B {sR
k %$I B {sR I jsR ts% R R$I sj R }s s Ys{ s jBR sR BtsZ sR 8? sR jj %sI s RZ R st{$s 7Bt {Bt{ t sIBR I $tPB 8s{$? Bt wR 8 `st R s jBR IsIBR I RY$I s sIBR I } }s sIBR {Zj$ts $BRD JZ {Bt $ t t $8s t RBt$IB k - B e- s}Bjs{$Bt R PZ Z $R sR }jsZR$Aj R I jBR 8? BIBR
s{ Zsj R I sj8s{ ts8$ t B I js $tPB 8s{$? Bt JZ s}s { t }B ` 8}jB t >i tI 9%BZR b$ Y is8s d nH
]$ s {Bt is8s
ej } B{ RB I sAs{$? Bt k j { Z s I js $tPB 8s{$? Bt t Zt RB}B 8s t? ${B w{$t s I$RJZ B I$R{B IZ BD R ? s AsRsIB t P t? B8 tBR JZ $t%BjZ{ st j 8s t $R8B wP t? B8 tBR I $tIZ{{$? BtD k js j { ${$IsI VZtJZ tB RBt RBjs8 t } R t s $%BR I jBR 8$R8BR VR? }B ` 8}jB jBR 8B B R j? { ${BR R AsRst t j 8B%$8$ t B I Y$jBR {BtIZ{ B R B R}$ sR t j R tB I Zt {s8}B 8s t? ${B ]BtR $ Zk t js 8st$P R s{$? Bt I JZ Zt P t? B8 tB 8s t? ${B %s $sAj t j Bt I Zts {B $ t j? { ${s $tIZ{$IsD $ 8}B } BIZ{ P { BR j? { ${BR w t R {sRB js s}s ${$? ej } B{ RB $t% RB PZ I R{ZA$ B }B j P? R${B Ist? R <stR ]Y $R $st ! R I wd TdMxdDU Zt {s8}B j? { ${B %s $sAj {Bt j $ 8}B t s Zt {s8}B 8s t? ${B e` 8}jBR I R P t? B8 tB s}s { t t js tB% js ]s j 7s st
]Bt s{ B
>]Bt s{ d MxH I j {? j A sR ? BtB8B k I$%Zj sIB {$ t ? h{B
et jjs Zt JZ$}B I $t% R $ sIB R R 8As {s t Zt 8$R $BRB %$s` Ys{$s
j { t B I js psjs-$s s AB IB I Zts ts% I$R K tsIs }B Zts {$%$j$9s{$? Bt - s R Ns IB{ B s ej stB V Bbsk $R s t %? I B BIB j %$s` JZ stR{Z s s%? R I Zt jsA $t B I
s Z` BR I ZRstB
w]s}? ZjB ED Ns } R t{$s I PZ t R 8? B%$j R I j {s8}B j? { ${B t j
$t $B I js ts% t s Zt {s8}B 8s t? ${B JZ AB s s{{$I t sj8 t BIB j 8s $sj %$I B ? sh{B sAsIB t {$t s
et js $t Rst tB% js }B RZ }jst s8$ t B I j } BAj 8s I j {Bt s{ B
ej - B I <? {Zj R
>qY < {Zj R q - d MEH I Fs{, {* %$ js I 7 OWeq I BAR %s{$? Bt R}s{$sj I { s Zt t$ 8? s ${B 8 tRs` s $h{$sj } B{ I t I Zt }? ZjRs
@n
R$ ZsIB t js {BtR js{$? Bt I <? {Zj R
_s s RZ }BR $B st? sj$R$R k I R{$P sIB j 8 tRs ` R sj8s{ tsIB t ]* =tB I jBR } RBts` R I R s AB s sj ZtB I jBR I$R{BR {B8}s{ BR k tB R j B{Z B s {BRs 8 `B JZ Z $j$9s Zt j { B$8? st ]B8B R K tsjs j I$ B $JZ j s { j? B R s s %$I t 8 t I Zts {BtPZR$? Bt
I j sZ B et jBR I$R{BR {B8}s{ BR jBR 8? BIBR I sAs{$? Bt k j { Z s tB RBt 8s t? ${BR R$tB Bt I Zt skB j? sR D k }B st B I$P? {$j8 t Zt $8? st }Z I sP { s s js B} ${BR w}B 8 I$s{$? ? $tPB 8s{$? Bt sj8s{ tsIs t R $}B I I$R{BR V Z8 t BR R$8$js R } 8$ t s jBR YZ8stBR I j hj8
es Y % RZR Y 3jk$t 7sZ{ R
Ys{ P t s js $t%sR$? Bt - s R U }s s stZjs
j {s8}B 8s t? ${B JZ } 8$ j %Z jB I jsR ts% R sj$ t? tsR {B8} tRstIB j P { B I js s% IsI jBR {$ t ? h{BR R R $I st Zt I$R}BR$ $%B JZ } BIZ{ Zt {s8}B j? { ${B %s $sAj eR {s8}B { s s js % 9 Zt {s8}B 8s t? ${B JZ $ tI s {Bt s R s j I js ts% V RZj sR I R B jBR }js $jjBR %Bjst R t Zts 8 8B sAj R{ ts R } {$}$ st R$t {Bt Bj {Bt s j RZ jB k {B8B R YsA$ Zsj js YZ8st$IsI RZj s %${ B $BRs
VZtJZ js %BjZ{$? Bt $tPB 8? s ${s t JZ tBR Ysjjs8BR $t8 RBR R$ Z t stIB {Bt $tZsT 8 t tZ %BR } B RBR A$ t R {$ B JZ R$t RZR{$ s ks js -} { s{$? Bt I st sK tB -$R t s? Zt }B t{$sj$IsI R ? 8$Is8 t -}jB sIsR JZ t st stI R -} { s $%sR js =ts I jjsR
sj$IsI %$ Zsj dn
R I {$ js }BR$A$j$IsI I RZ8 $ s jsR } RBtsR t 8ZtIBR t sIBR $tT
3Z t I 8$R$? Bt sI$B sRB{$sIs s Zts R jjs I t Z Bt R t ? s}$Is B s{$? Bt
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
N
3$ ; d( VYB s R 8Zk P? s{$j Zs Is js $tPB 8s{$? Bt g{sR$ st B {B8B } I js 5+Z$? t tB Ys AB sIB s{{$I tT sj8 t Zt h{Y B B s {Y$%B R$t t Zts {B}$s I R Z $IsI 2 PB 8? s ${s8 t sA %? sR s}sR$Btst R WB R s s ks I sj8s{ ts k } B{ Rs js $tPB 8s{$? Bt R$tB I { s k I stR8$ $ } { }{$Bt R JZ $t{$I t RBA %s $BR R t $IBR s js % 9 w%$R s B? IB s{ BD k } R t s $8? s t R JZ R}BtI t t j s{ B s jBR 8B%$8$ t BR } B}$BR Ns sj$IsI %$ Zsj s} tsR R sAj { I$P t{$sR t js 8 t k j {Z }B z R $IBR {Bt Zst R {sR{BR k st B`BR s $AB sIBR I R tRB R R BR 8BI tBR -}jB sIB R I 8ZtIBR %$ Zsj R R sR 8 `st s jBR } $8 BR RZA8s $t$R sR B{sIBR {Bt RZR R{sPstI sR I A Bt{ k 8AZ $IBR t RZR s` R $8} 8 sAj R
* RI jBR sK tBR B{Y t s t JZ R s{ZK ts ? s j ? 8$tB t jBR {? {ZjBR $tPB 8? s ${BR j 8s I js sj$IsI %$ Zsj Ys I R} sIB Zt st $t ? R t jBR tB% j$R sR k Z$Bt$R sR I j ? t B Ns tB% js
W Z B8st >W Z B8st{ d M;H I G$jj$s8 p$ARBt R ZtB I jBR -}Bt t R 8? sR {$A R}s{$B R
{js BR sZtJZ } R t s R? BjB Zt sR} { B }s ${Zjs I j %sR B 8s I js sj$IsI %$ Zsj V s%? R I js BR t js9sIBR R I R{ $A Zt PZ Z B { {stB t JZ R }BR$Aj js {Bt -$? Bt I$ { s I j { A B YZ8stB k I j R$R 8s t %$BRB {Bt js I jBAsj I $tPB 8s{$? Bt ej
Zts sj$IsI sj ts $%s IBtI {Bt%$% t tB R? BjB 8 t R YZ8stsR R$tB s8A$? t $t j$ t{$sR s T $h{$sj R Ns B $ $tsj$IsI I R }jst s8$ t B Zt$IB s RZR 8? Zj $}j R j { Z sR $t } s{$Bt R k }BR$A$j$IsI R Ys IsIB jZ s sj I Rs BjjB I Zt RZA ? t B }B}Zjs IZ st js I? {sIs I jBR B{Y t s I tB8$tsIB >d M1H B
{kA }Zt, et ? j R $t{jZk t } j? {ZjsR 8Aj 8? s ${sR {B8B jsI iZtt z$I BI B8 >d M1H 7$ ZtBR }? s sPBR 8? sR s $As YsAj? sAs8BR I { I s jBR B I tsIB R
j {Bt Bj I jsR ts% R $t R js R t {sRB I {Bt4${ B A? j${B k }Z R BR s R} {Zjs Zt }B{B 5}B JZ? tB IZ{$ sj {$A R}s{$B B R}s{$B %$ Zsj j jZ s I? BtI sj$9s {Bt $ tIsR Z T sR2 7 YsA ? s s{sAsIB I Zts % 9 }s s R$ 8} R$t s} tsR {BR {Bt? B8${B t$ }? I$Is I %$IsR YZ8stsR js js{ s I js Z s NsR }BR$A$j$IsI R t %$R sR {B8B }Z I s} {$s R RBt 8? Zj $}j R
© Los autores, 2001; © Edicions UPC, 2001.
-
* $t Bt s e$tR $t
3$ ; dd ZtIBR $8s $ts $BR }s s s8st R I jBR `Z BR I B I tsIB 7? BjB JZ R s % 9 ZtB PB 8s }s I j `Z B 3B B s8s I js } j? {Zjs GT*J >q Bt d M1H
_ j? {ZjsR {B8B q Bt >d M1H k * s8R{s} >d M;H tBR $t BIZ{ t t B BR sR} { BR I js sj$IsI %$ Zsj et js } $8 s Zt $tPB 8? s ${B R} {$sj$R s t j I$R K tB I `Z BR }s s B I tsIB %$% Zts $t{ ? Aj s% t Z s t jsR t sK tsR I j } B}$B B I tsIB IBtI R tP t s s RZ } B}$B } B s8s et js R ZtIs Zts } RBts {Bt }BI R }R? JZ${BR R } RZsI$Is }s s JZ B8 }s t Zt -} $8 t B IBtI s} tI s t s t j RZ K tB I B sR } RBtsR $t s{ Zs {Bt jjsR ej {B sIB I {? R} I >qY Nsbt8Bb st d 1H RZ R {Z js ej {B sIB I {? R} I 1 ? sR sjj? s I j {$A R}s{$B >Nsbt8Bb st 1U kBtI ]kA R}s{ d xH k FBYttk t 8Bt${ >d xH RBt sj ZtsR I jsR } j? {ZjsR I {$ t Ps{ Z s JZ tBR I R{ $A t s YZ8stBR s s}sIBR t 8ZtIBR $ sj R IBtI tB -$R t 8? sR j$8$ s{$Bt R JZ jsR JZ js } B}$s $8s $ts{$? Bt $8}Bt et R s Z ?j $8s R I R{ $A {B8B Zt st sI jst B I j PZ Z B Zt $8}jst { A sj {s}s9 I sj8s{ ts d $ sAk I $tPB 8s{$? Bt Zts {s}s{$IsI I sj8s{ ts8$ t B ks RZ} sIs t js s{ Zsj$IsI et js tB% js I ]Btt$ G$jj$R i 8s, >d xH jsR ? {t${sR s%st9sIsR I js sj$IsI %$ Zsj } 8$ t {s8A$s s %BjZt sI jBR s{ B R I jsR } j? {ZjsR $t{jZRB s}s { ZtB 8$R8B ej {js8B }ZAj${$ s $B }BI ? s R U g<? s sR ZR I Zt IZ}j${sIB k %$%s }s s R$ 8} t j 8ZtIB %$ Zsj JZ ZR I JZ$ s ]B8B 8Z R s I js s{ Zsj$IsI I R s 8? s ${s }BI 8BR {$ s s8A$? t IBR I jBR js BR htsj$R sR I j _ 8$B =_] I tB% js I {$ t{$s h{{$? Bt t RZ I${$? Bt I d E 7 s s I ] ts {sj t sIs I FB I$ $ ? B k isPs j RBj? k *s I {B8 sj R I$ t B I eIZs IB psjj B k pZ$jj 8 7? st{Y 9 eR s Z ?j $8s R Zts I$% $Is Y$R B $s RBA
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
1(
Zt } BP RB Zt$% R$ s $B tP t sIB s Zt {Bt R s s $B } B{ RsIB I - BR 57 ? st sR? jBR } B s8sR $tPB 8? s ${BR I j PZ Z B2 Ns }BR$A$j$IsI I { s {Z IBR s $h{$sj8 t $I s I$PZtI$Is }B } j? {ZjsR {B8B * RsP? B B sj >qB sj i {sjj d (H RZj s s8A$? t s}sR$Btst * R Ps{ $Aj R s }BR$A$j$IsI {Bt{ A$Is t j s ?8A$ B I js {$ t{$s h{{$? Bt } 8$ $ ? s }B ` 8}jB s{ j s j $ 8B I j s} tI$9s` <Bk t I? s {Bt jBR {Bt $tZBR sI jst BR k js 8Zj $}j${s{$? Bt I j %BjZ8 t I {BtB{$8$ t BR I tZ R s RB{$ IsI R s8BR tI$ tIB s js t { R$IsI I $t{ 8 t s jBR sK tBR I s} tI$9s` R{Bjs B Zt$% R$ s $B _ Bt B tBR {Bt% $ 8BR t tBR R ZI$st R $t{s}s{ R ks tB R? BjB I sR$8$js R$tB R$8}j 8 t I sP Bt s js $t t {st $IsI I $tPB 8s{$? Bt k {BtB{$8$ t BR JZ R t st {BtR st 8 t <sA 8BR 8Z B I %$ `BR st R I YsA sIJZ$ $IB jBR {BtB{$8$ t BR $tI$R} tRsAj R Ns $8}jst s{$? Bt { A sj I {BtB{$8$ t BR JZ } 8$ IZ{$ sj 8? t$8B j $ 8}B t { Rs $B }s s sR$8$js jBR }Z I R js RBjZ{$? Bt VZtJZ {js B R$ st R sj{st9s8BR js $t8B sj$IsI 5s JZ$? t j } B{Z}s j $ 8}B t$ tIB BIs Zts t$IsI }B I jst 2 _B j 8B8 t B sj ZtBR R ZI$BR Yst I 8BR sIB JZ js R $8Zjs{$? Bt j? { ${s I sj ZtsR $Bt R I j { A B }Z I skZIs s I %Bj% {Z IBR Bj%$IsIBR sj t$% j {BtR{$ t ]ZstIB R B R {BtB9{s {Bt 8? sR } B}$ IsI }BI 8BR }B ` 8}jB {B Is jB JZ Zts % 9 s} tI$8BR R$t 8? sR RPZ 9B JZ sj$9s Zts R $8Zjs{$? Bt j? { ${s I js $? Bt { A sj {B R}BtI$ t =t tPBJZ I$s8 sj8 t B}Z R B s}s { t j js B NsR Z$tsR I 8$ { A B >7, {Y R V8Bt Y iZ$tR BP k $tI d nH I _Y$j$} F 3s 8 IBtI Zt - sK tB BA` B sj$ t? ts I j s8sK tB I Zt } JZ K tB sR B$I Ns ABjs R R$ ? Zs t Zts B ? A$ s { {sts s js q$ s k s AsR I } B%B{s Zts }? I$Is }sZjs $ts I js 8 8B $s I jBR YZ8stBR j R %s I R}BR k tIB I RZR {Z IBR _B{B j JZ Is s ZtB R$ t$ st R$JZ$ s R IZ K tB ks I RZR } B}$BR {Z IBR et {s8A$B j B{? stB %$%B JZ I R{ $A 7 st$Rjsb N 8 t RZ 8s $R sj tB% js 7Bjs $R >d EdH {Bt% $Is t Zts } BPZtIs k 4 -$%s } j? {Zjs >d dH 8s $sj$9s jBR {Z IBR I jBR YZ8stBR JZ $t t st R sAj { {Bt s{ B {Bt j 8$R8B
; ;
NBR w}R ZIBD}BI R I js 8 t
7 Ys % t$IB R} {ZjsIB 8Z{YB RBA jBR }BI R }B t{$sj R JZ t{$ s js 8 t YZ8sts Vj ZtBR j$A BR }R ZIB{$ t ? h{BR RBR $ t t JZ j YB8A Z $j$9s RBjs8 t t Zt d( k Zt 1(0 I RZ {s}s{$IsI 8 t sj I sj PB 8s JZ -$R Zts st {st $IsI I YsA$j$IsI R B P t? B8 tBR JZ R} st t R sIB I Y$A ts{$? Bt s R I R{ZA$ BR k Z $j$9sIBR 7 YsAjs sR? I js Ps{Zj sI }s s 8B% BA` BR s I$R st{$s j JZ$t R$s j j } tRs8$ t B j }s ? s B sI$%$ts j PZ Z B {js $%$I t{$s }B {$ s R? BjB sj ZtBR I jBR 8? sR {BtB{$IBR * RI R$ 8} j YB8A Ys $t t sIB % t{ jZI$ B B8} jsR As sR P? R${sR JZ j$8$ st t {$ s PB 8s RZ j$A sI i RZj s {js B JZ j {Bt Bj I js 8 t } 8$ $ ? s I$AZ`s Zt YB $9Bt 8Zk I$P t I j s{ Zsj@;
=t st? sj$R$R { ? ${B I jBR I$% RBR sR} { BR I js }s s}R${BjB ? s k B sR }R ZIB{$ t{$sR sZtJZ t { Rs $B t jBR $ 8}BR JZ {B t {s PZ s I j sj{st{ k } tR$Bt R I R j$A B i 8$ $8BR sj j { B $t RsIB s Ns {$ t{$sU jB AZ tB jB 8sjB k jB PsjRB >d MdH I j 8s 8? s ${B k I$%Zj sIB s $t ps It k s 3 sZI R }s stB 8sj R >d ;H I Fs8 R istI$ k s jsR P t{$sR JZ t s8ABR - BR R {$ st d;
© Los autores, 2001; © Edicions UPC, 2001.
1(M
* $t Bt s e$tR $t
Ns {$ t{$s h{{$? Bt Ys Z $j$9sIB j s8}j$B sAst${B I YsA$j$IsI R t jBAsIsR As`B jBR ? 8$tBR }s sP? R${s }s s}R${BjB ? s B R$8}j 8 t }s s{$ t{$sR sj % 9 t Zt $t t B I {BtIZ{$ j $8}s{ B t s $%B I }sjsA sR JZ$%sj t R {B8B B{Zj $R8B k 8s $s et R R t $IB js {$ t{$s h{{$? Bt Ys $t t sIB Ys{ ZRB I jBR }BI R 8 t sj R I Zts 8st s % BR? 8$j R sAj {$ tIB Zts I$R $t{$? Bt RZAR st{$sj t $8} BAsAj R }BI R I js 8 t k }BI R }R$? Bt${BR R ? Zt j ? 8$tB $t BIZ{$IB }B j I$ B FBYt G ]s8}A jj t jsR }? s $tsR I js }B}Zjs %$R s VR BZtI$t 7{$ t{ 3${ $Bt eR {Bt{ } B I ht$IB {B8B j { ? Bt${s }R? JZ${s t jBAs ? s BT IsR sJZ jjsR YsA$j$IsI R R} {$sj R JZ }BI ? s sj$9s js 8 t k JZ s } Rs I BA I { s RZ}Z R sR j k R P? R${sR s? Zt tB I R{ZA$ sR R ? st RZR{ } $Aj R I R } $IsR {B8B {ZsjJZ$ B B -} $8 t B B P t? B8 tB P? R${B sj eR s R} {$ I PZ 9s 8 t sj }BI ? s R t sIs k {Bt BjsIs 8 I$st I$R}BR$ $%BR P? R${BR Ns }BR$A$j$IsI I JZ j YB8A sIJZ$ s sj t BR B YsA$j$IsI R 8 t sj R I R $}B R {Bt 8}jsIs t js {$ t{$s h{{$? Bt {B8B P Z B I js } B}$s sR s%st9sIsRD %BjZ{$? Bt I js YZ8st$IsI ws{ j sIs B tB }B j {Bt s{ B {Bt {$%$j$9s{$Bt R 8? 7 s s I Zts - s}Bjs{$? Bt JZ I RI j }Zt B I %$R s A$Bj? B ${B }s { tI s }B t{$s js 8 t t I $8 t B I j {Z }B ]B8B {BtR {Z t{$s I js %BjZ{$? Bt js YZ8st$IsI I j PZ Z B sIJZ$ $ ? s YsA$j$IsI R 8 t sj R $tRBR} {YsIsR RZ} stIB js I } tI t{$s I js {tBjB ? s VR? j R B $}B I j YB8A I j PZ Z B I $t j$ t{$s RZ} $B R Zts {sA 9s tB 8 IBtI R sjB`s Zt { A B 8? sR stI RBA Zt P ? s $j k } JZ K tB {Z }B NB {Zsj tB I `s I R {Bt sI${ B $B }Z R B JZ Zts {sA 9s 8skB JZ$ Zt {Z }B 8? sR BAZR B }s s RBR t js Ns sj ts $%s sj {B8B s% t Z s < A p G jjR t RZ tRskB ej YB8A I j sK tB Zt 8$jj? Bt >dM nH R JZ js YZ8st$IsI I Rs ? }B{s PZ Z s YsA ? s I `sIB I stIs k }sRs ? s j $ 8}B RZ8 $Is t stJZ R I 4Z$IBR tZ $ $%BR I I${? stIBR R? BjB s } tRs et Zt {Z $BRB js B ej YB8A JZ %BjZ{$Bt? B >qY st bYB e%Bj% I d ndH I eI8BtI <s8$j Bt Zt {$ t ? h{B JZ I {$I stsj$9s js %BjZ{$? Bt PZ Z s I j YB8A -} $8 t s t RZ {Z }B j AB8As I B {Bt skBR {? BR8${BR 7Z}Z R s8 t R } B{ RB s{ j s js %BjZ{$? Bt I RZ B st$R8B k s{sAs stRPB 8? stIBR t Zt RZ} { A B JZ sj htsj JZ Is {Bt% $IB t Zt t }jsR8? s ${B t Zt B tB s jBR B ? t R % IsI s8 t ` 8}js <Bk t I? s RsA 8BR JZ j s8sK tB I j { A B tB Zs Is Zts js{$? Bt I$ { s {Bt j sIB I $t j$ t{$s I j 8$R8B VZtJZ tB R$ 8} PZ sR? k I sY? JZ R$ s } R t ? stIBR t js h{{$? Bt j s $AZ B I j s8sK tB {B8B R$ tB $t JZ? %B{B I $t j$ t{$s z? sR }B ` 8}jB s jBR sj$ t? tsR JZ s}s { t t yt%sI R P B8 s R >d xnH k t qY$R yRjstI es Y >d xxH *Z st AZ ts }s I j R$ jB y R { k? B JZ jBR YB8A R 8? sR 8$t t R I js RB{$ IsI I A? st }BR st { A BR I { A BR 8skB R wk JZ YB8A R I s9s t s 8Z` R k {jsR R }BA R t? s8sK tB 8 tB jB JZ % t? s s `ZR $h{s j jZ s $tP $B JZ B{Z}sAst t js RB{$ IsID _sZj s {j? t${s P st{? R PZ Zt sAstI sIB I R sR B{s wdM1;TdMM(D Zt 8$t t } BP RB I {$ Z ? B ? sR et jBR 8 I$IB R I {sA 9sR B { st B8 $R sR I j R$ jB y js I$R {{$? Bt I {Bj sR Psjj {$IBR JZ t? s }B BA` B js - s{{$? Bt }s s js }BR $B 8 I${$? Bt k } RsIB I j { A B jj ? B s {Bt% $ R t Zts } ? s{ ${s YsA$ Zsj e8ZjstIB sj IB{ B z? { B 3 st, tR $t I js h{{$? Bt }ZAj${sAst j$R sR {B8}s sIsR s 8 tZIB I ? tIBj BP tR$%s wg $ { A B R 8skB JZ j ZkB D _ B t$ jBR 8? sR s{? $8BR I P tRB R I R sR } ? s{ ${sR IsAst js sjjs ej { A B I j } B}$B B{s R? BjB } RsAs d!;1; Zt }B{B 8? sR I js 8 I$s w j } RB 8 I$B I Zt { A B YZ8stB sIZj B BR{$js t d!n(( k d!;(( D } B {B8B R K tsjs j {BtB{$IB }sj Bt ? BjB B 7 }Y t Fsk
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
pBZjI t RZ $t Rst ? R$8B R ZI$B RBA j 8s Ns PsjRs 8 I$Is I j YB8A >d M;H tsIs }s s $ sjs I stIB ej { A B I j 8s 8? s ${B sj 8? st s j 3 $ I ${Y psZRR wd TdMxxD } R? B d ; 1 s} tsR }B t{$8s I js 8 I$s sZtJZ 8BR sAs Zts $JZ 9s I {$ {Zt%BjZ{$Bt R 8skB JZ js I {ZsjJZ$ B B I$R {sIB YsR s js P {Ys ! BR 8Z{YBR YB8A R I } B I$ Bt 8s {sR sj8 t }BA R 8$ t sR JZ { $8$tsj R k B sR t R I 8sj %$%$ As ? st ? {B IR I } RB * R{s sIs }Z R js js{$? Bt I j s8sK tB I j { A B {Bt js $t j$ t{$s jBR $t% R $ sIB R s{ Zsj R R$ Z t {B8}s $ tIB RB R? Zts PsR{$ts{$? Bt }B j { A B $I? t ${s s js I RZR st { RB R !
q j? }s sR k t Z BtsR Ns sIJZ$R${$? Bt }B %? s %BjZ $%s I YsA$j$IsI R 8 t sj R JZ sYB s j YB8A tB }BR R Zt }jst s8$ t B JZ t{Bt s8BR t tB% jsR {B8B ej ht I js $tPst{$s >]Y$jIYBBI:R etI d x;H I V YZ ] ]js , IBtI j {Bt s{ B I jBR YZ8stBR {Bt js s9s RZ} 8s I jBR p stI R R K tB R $tR sZ s j R sIB I }s9 k A$ t R s t Zt 8ZtIB Z ? B}${B IBtI js j }s ? s k B BR }BI R 8 t sj R BA$ tst js %BjZ{$? Bt I j YB8A ej ZRB I jBR }BI R 8 t sj R sIJZ$ $IBR }B jsR }BR $B R t s{$Bt R I t$K tBR s{sAs {Bt I 8BR s{$Bt R st R} { s{Zjs R {B8B js sj s{$? Bt I js B s{$? Bt I js NZts Ns t ? s t { Rs $s }s s I Rs Bjjs R sR $ ? st${sR k sRB8A BRsR s sR tB }s { RZj s Zt } BAj 8s sR s {Z $ s js R %s $ts B sAj I t ? s JZ }Z I - s R I }B ` 8}jB Zt Zt$% RB }s sj jB VZtJZ {js B R ? s R$ }s s t{Bt s Zts AsR 8? sR B 8 tBR R? Bj$Is }s s Zt s Z8 t B $t% BR? 8$j t { R$ s8BR {Z $ s B B tB 8 tBR $8} BAsAj tB YsA 8BR s%st9sIB 8Z{YB JZ I$ s8BR ej B $ t I R $}B I 8s s%$jjBRBR }BI R R sRB{$s }B jB t sj {Bt YsA$j$IsI R $tts sR I j R YZ8stB JZ }BR t BIBR jBR $tI$%$IZBR k JZ R? BjB jj st s 8st$P R s R t ZtBR }B{BR et ej YB8A {B8}j B >qY GYBj st d E;H I FBYt Ztt jBR YZ8stBR JZ {B8B j I PB 8 p k <BbRBt }BR t Ps{Zj sI R }s stB 8sj R RBt {jZ sIBR }B jsR Ws{$Bt R =t$IsR k {BtR $ Zk t js s%st9sI$jjs I js YZ8st$IsI PZ Z s et js R $ I tB% jsR NBR YB8A R j t >N tR8 t d x(H I e e 78$ Y R I R{ $A s R R {Bt Zts $j$8$ sIs } { }{$? Bt R tRB $sjU }Z I t % t js BR{Z $IsI 8$ s s s%? R I BA` BR R? Bj$IBR % j $t $B I j {Z }B ]B8B 7Z} 8st } B t YZ8stB %s8BR VZtJZ I R Ps{ $Aj R js Z $j$9s{$? Bt I R BR }BI R I A JZ $ Zt RPZ 9B s B sIB VR? R ts s t js tB% js Fs{, BP es j R >d ; H I Fs8 R j$RY IBtI s RZ } B s Bt$R s tB j AsR s {Bt I R s JZ sj B RZ{ IsU I A 8st `s js sj$IsI JZ -$R I ? sR I {sIs I R B _s s j %st s Zts 8 Rs {Bt j } tRs8$ t B wYsA$j$IsI JZ R ? Zt R s ` s }R ZIB{$ t ? h{s I tB8$ts ? s8BR j JZ$t R$sD I A %$RZsj$9s BIBR jBR s ? B8BR k }s ? {ZjsR I js 8$R8s k {B8} tI 8st$}Zjs k RBj% jsR {Zs{$Bt R P? R${sR JZ I R{ $A t s PB 8sIs }B ZtBR d(1M ? s B8BR VR? }Z R j js }BR${$? Bt I js 8 Rs =ts 8 Rs I d8n R ? t? Z8 B I {Zs{$Bt R JZ I A ? s {BtR$I s B8stIB sj 8 tBR Zts {Zs{$? Bt }B s ? B8B R ? s ? IZs s s I d(1M gV V % { R js YsA$j$IsI sIJZ$ $Is }Z I {Bt% $ R t Zt s8s B jsR t % 9 I t Zt }B t{$sj I }BR$A$j$IsI R {B8B RZ{ I t ej YB8A t j jsA $t B I iBA 7$j% A *${, Zjj j t%$sIB YZ8stB sj 8ZtIB I jBR Y$I stBR Zts s%st9sIs s9s - s sj? s{ ${s %Z j% s js q$ s sR j {Bt s{ B {Bt% $IB t Zt s} R sIB 8 t sjU "_Bt { {s I 8? k tP 8sR > H 7Bk Zt stR8$RB I js } R k js } R JZ {Bt s $B R js % IsI Ns YZ8st$IsI
© Los autores, 2001; © Edicions UPC, 2001.
@
* $t Bt s e$tR $t
3$ ; d1 NBR - s R R {sA 9Bt R k I R{sRs sjjs P? R${s jBR } JZ K tBR YB8A {$jjBR % I R wj$ j t 8 tD RBt j {j${Y? I s9s $t j$ t JZ sAZtIs t jsR } j? {ZjsR k tB% jsR RBA $t%sR$Bt R wV $AsD et js } j? {Zjs h{BR sj$ t? tsR $t t st 8s s s RZR %? { $8sR $tk { ? stIBj R {Bt yt%sR$Bt BP Y 7sZ{ 8 t >d x H jBR tsIs }s{? jsR s Z`sR I RZR I IBR j sj{BYBj JZ R st _B RZ BIB JZ Is t Zts 8BtZ8 t sj {B B 9s wVAs`BD NBR A j${BRBR 8s {$stBR I js {$ t s R V s{,R >d EH I$R}Bt t I Zt 8s t? h{B s R tsj A? j${B k $ t t Zt 8sj {s ? s{ $8} R$Btst _B jB JZ }s { js $t j$ t{$s tB R ? s K t$Is {Bt j s IB Z B
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
@@
$ t 8Z{Ys RZ }B JZ {sIs ZtB I RZR 8$ 8A BR R ? s t{ sIB I t B I RZ } B}$B { A B _B JZ R$ Z%$? s8BR Zts B $ s I j }s ? s R$8}j 8 t js Ps{Zj sI $ts ${ZjsIs JZ t B kB R ? s8BR $t{s}s{ R I RB}B s tBR Ns RB{$ IsI YZ8sts R ? s $8}BR$Aj gWB }Z I RB}B s j ZPB I RZ } B}$s s9s I j sj8s I js s9s > H NB JZ jBR Y$I stBR j YsA? st IsIB tB s Zts % IsI s j }s ? s Zjj tB }BI? s j 8 t R t$ }BI ? s {B8Zt${s RZR } tRs8$ t BR s jBR I 8? sR NB JZ Rsj? s s {B8B Zt {YB B I } RBtsj$IsI Zt B t I { ZIs I R R} s{$? Bt Zt ? B I } tsR k I 8B I$8$ t BR j {Bt t$IB I jsR {jBs{sR I j sj8s WB }BI? s {Bt t jB " * tZ %B iBA 7$j% A t js tB% js j } 8$ %Bj% R
8? sR YZ8stB k sAstIBts RZ 8s $ts{$? Bt ej 8s I js sj$ ts{$? Bt I j BA` B I js tB% js ej YB8A R B{? sR ${B >qY 7 B{YsR ${ st d xH I j 8$R8B sZ B k I VtI ]YsBR *$ I >d (H I FBstts iZRR et ? R s Z ? j $8s jBR YZ8stBR I Zts j `sts {BjBt$s t j R JZ }BR }BI R - sR tRB $sj R w_e7D P t sj 8ZtIB I jBR YZ8stBR R s8A$? JZ Yst s} tI$IB js j }s ? s I ZtBR - s R R R tP t st s js 8s $ts{$? Bt }B }s I jBR YZ8stBR tB 8sj R
d 1H sAB Is js Y$R B $s I Zt j? }s s {ZkBR }BI R R %st I R%st {$ tIB =ts }? I$Is JZ
Z B }B I t B >*k$t ytR$I
7$t {Z $ s $t`ZR $h{sIBR }BI R RZj s s8A$? t }BR$Aj sj$9s s{{$Bt R wtB st R} { sT {Zjs R {js BD % IsIsR s js 8skB ? s I 8B sj R _B ` 8}jB {Bt Zt t ts8$ t B sI {ZsIB Bt sj ZtsR } RBtsR }Z I t jj s s {Bt Bjs {$ sR s{{$Bt R $t%BjZt s $sR I j {Z }B w%s $s{$?
7 }$ t I j RZ K tB >* s8Rts, d MH IBtI jBR YB8A R RBt {s}s{ R I {Bt Bjs s %BjZt sI RZ P $j$IsI ]B8B s8A$? t jBR R$R 8sR I {Bt Bj I js 8 t k I j {Z }B I R{ $ BR t *Zt >d ExH js Rs s I 3 st, < A ej t$ 8? s ${B } RBts` I ej IB{ B sAZR >d 11H Z $j$9s RZ }B t{$sj 8 t sj }s s 8st$}Zjs Y$}t? B ${s8 t s RZR R 8 `st R s{ $ ZI AsR st RB{B $Is }B jBR 8sj%sIBR {$ t ? h{BR JZ }Z Ajst jBR jsAB s B $BR I js h{{$? Bt 7 s s I YsA$j$IsI R JZ {B8B js Y$}tBR$R tB {s t I t B I j s ?8A$ B I jBR }BI R }R$? Bt${BR IsIB JZ tB s}s { t
I j $ 8B {s I? s{B B R}$ s B $B D eR s R js } B}Z R s I js tB% js I zBtIs W {yt k
jsR }B t{$sj$IsI R I RZ { A B 8 I$st Zts $t h{$ B I tsIB T{ A B
}s stB 8sj k 8? sR Ps{ $Aj I RI j }Zt B I %$R s A$Bj? B ${B I PBtIB I js 8s t? h{s tB% js 3jB R }s s Vj tBt >3jBb R PB Vj tBt d EEH I *st$ j ZjB ]Ys jk >d EMHD IBtI Zt I$R8$tZ$IB }R? JZ${B jj s k R wjj %sIs s js }st sjjs {Bt j ? s{$sR s jjsR s R Zt t$B sZtJZ I PB 8s stR$ B $s Vj B R$8$js s jB JZ j RZ{ I sj `B% t sRsIB 8 t sj t js } j? {Zjs ej {B sIB I {? R} I s AsR t R {sRB I sZ8 t s {$sj qs8A$? t t Zt }jstB 8 tBR j ZRB I I B sR }R? JZ${sR }s s }B t{$s }B ` 8}jB YsA$j$IsI R $t j { Zsj R R j 8s
$8}j${sIsR PZ 9sR I R{BtB{$IsR R$tB JZ R JZ$ RBjs8 t Zt {$ B sI$ R s8$ t B R} T
NsR }BR$A$j$IsI R JZ B B st js Z $j$9s{$? Bt I R $}B I }BI R 8 t sj R RBt } ? s{ ${s8 t $j$8$ sIsR _B ` 8}jB t js tB% js 8 I$BR I stR}B JZ Ist BARBj BR {ZstIB js t 8}$ 9s s %$s`s {Bt j RBjB }BI I RZ 8 t eR ? s {js B 7$ }BI 8BR j stR}B s tBR sjj? IBtI JZ s8BR {Bt R? BjB I R s jB 5}s s JZ? t { R$ s8BR Zt % Y? {ZjB2 eR B }Z I R$ t$h{s s8A$? t j ht I js -}jB s{$? Bt R}s{$sj et t {Bt s{ B {Bt B sR s9sR sj$ t? tsRU tB P? R${s8 t s s%? R I j %Z jB R}s{$sj R$tB 8 tT sj8 t s s%? R I j I Rs BjjB I "st{ R sj R I$R{$}j$tsR P? R${BT8 t sj R" Ns {B8Zt${s{$? Bt
gq$ $ >q$ q$ d xEH I VjP I
R jBR
e8As`sIs sj$ t? ts >Vj$ t e8AsRRk d H I yst Gs RBt j YB8A Ys {BtR Z$IB t s
© Los autores, 2001; © Edicions UPC, 2001.
@
* $t Bt s e$tR $t
$t R js R ? s I RI jZ B s8A$? t sR Z sIs N 8BR t >V{ BRR s
V s%? R I Zt A$jj? Bt @N I sK tBR
$jj$Bt O s R d E H I iBA 7$j% A U "7$ }B sj B js j }s ? s R j Z ? t${B 8 I$B
} ? s{ ${B I {B8Zt${s{$? Bt $t R js R I RI jZ B }B JZ tB Ysk $t P t{$sR t$ R ? s ${s t$ sRBR }B js js $%$IsI I j $ 8}B t$t ZtB I jBR IBjB R I {sA 9s k jBR $t{Bt% t$ t R JZ RZ}Bt Zt 8 I$B I {B8Zt${s{$? Bt tB 8sj " sR s {Bt{ t s R }Bt R t {Bt s{ B {Bt j
} ? B-$8B j? }s s I js {sI ts I stR8$R$? Bt k t%$s j 8 tRs` JZ jj s $tR st ? st s8 t sj jZ s I R sIB VR? I R t{$jjB
et
=t st$jjB sj I IB I j 7Bj
>i$t V BZtI Y GB jI d x1H j sZ B ]j$&B I * 7$8s, }Bt
t AB{s I ZtB I jBR } RBts` R I js tB% js js `ZR $h{s{$? Bt I js }BR$A$j$IsI I js stR8$R$? Bt I j } tRs8$ t B s I$R st{$sU I$h{Zj sIU "7$ js j }s ? s -$R $ R js I$R st{$s tB } R t s ? s t$t Zts _B JZ js 8 t tB R Zt BA ` B
Zt ,$j? B8 B B Zt sK tB jZ9 5JZ? $8}B s ? st2
s R s jBD s jsR j k R R ? Zt jsR {Zsj R tsIs }Z I -{ I s js P? R${B WB R ? s RZ` s wB tB I A ? % jB{$IsI I js jZ9 " 7 s s I Zt $}B I s Z8 t B } $tB Z $j$9sIB {Bt P {Z t{$s }B jBR I P tRB R k { k t R I jsR }R ZIB{$ t{$sRU j {Z RB s BA ` BR PZ 9sR B t ? sR JZ {s t 8? sR sjj? s I j s ?8A$ B I s}j${s{$? Bt I js {$ t{$s
Bh{$sj
k JZ t{Z t s RZ `ZR $h{s{$? Bt wk I sY ?
Zt $t{$}$ t {BtB{$8$ t B JZ R $ t I jsR I$h{Zj sI R }s s As $ jBRD t R {sRB t j s? jBR } B{ RBR JZ s{Bt { t t j { A B 7$t 8As B js B ? s I js js $%$IsI R} {$sj JZ R sAj { js $8}BR$A$j$IsI I js stR8$R$? Bt I js $tPB 8s{$? Bt s % jB{$IsI R RZ} $B R s js I ZjB ED js jZ9 $t%sj$Is {ZsjJZ$ AsR P? R${s }s s R $}B I sj t B B YsA$j$IsI 8 t sj w]s}?
Ns -}jB s{$? Bt I js Y$R B $s }sRsIs s s%? R I Zt BA ` B JZ s{ ? Zs {B8B {s sj$9sIB RZ}Bt B s I jsR $t{ ? Aj R }B t{$sj$IsI R JZ }Z I I Rs Bjjs Zt R JZ
$8} ts ? s
jBR BA ` BR 7 s s I Zts $I s Z $j$9sIs t
I ]Bj$t G$jRBt k t js $t Rst
R tR$Aj qY _Y$jBRB}Y :R 7 Bt 7$ %$R sR I js s st s !jIZ%s$ > H
sj $R B }R ? JZ${B >d E H
>7 % t z$ bR BP !jIZ%s$
pB d xH I $, i Rt${, IBtI R{ $A U
"Ns {Bt 8}j? IZ st js B s B 8$ t sR
8 } }s sAs NZ B j t s8 t {Z$IsIBRs8 t sj ? 8$ R Z{ Z s k I `? JZ 8$ {Z }B 4Zk s t{$8s k sj I IB I jjs js t%Bj%$ s k sR$8$js s RZ Y$R B $s {Bt% ? t
Zts RBjs {BRs {Bt js }$ I s " NBR } BAj 8sR RZR{$ sIBR t PZ Z sR RB{$ IsI R YZ8stsR }B js } R t{$s I $tI$%$IZBR IB sIBR I R $}B I }BI R RBt I R{ $ BR t } j? {ZjsR {B8B >d M(H t R} { s{Zjs R R{ tsR
7{stt R
eR s {$t s tBR $t BIZ{ t Zt 8ZtIB IBtI jsR jZ{YsR = $j$9stIB Zt P t? B8 tB P? R${B
8 t sj R $ t t {BtR {Z t{$sR I %sR sIB sR }s s jsR } RBtsR
{BtB{$IB w t j {Zsj R AsRs I${YB R s I }sRB j PZt{$Bts8$ t B I j YB tB I 8${ BBtIsRD js I } tI t{$s I js 8} s Z s I Zt {Z }B {Bt js % jB{$IsI 8 I$s I jsR }s ? {ZjsR JZ jB PB 8st
7{stt R
}jst s JZ sj s{ j s j 8B%$8$ t B I I${YsR }s ? {ZjsR R }Z I {BtR Z$
Zt I s8? s ${B sZ8 t B I js 8} s Z s {B }B sj JZ Ys s -}jB s js {sA 9s B $t{ tI$s j {Z }B et js tB% js }s sI$ 8? s ${s RBA j 8s d x1H I VjP I
R R ts s Zt { $8 t t Zts RB{$ IsI I
ej YB8A I 8Bj$IB j? }s sR
>qY * 8Bj$RY I st t i ${Y
U j sR R$tB
Z $j$9s 8 {st$R8BR I AjBJZ B 8 t sj }s s YZ$ I j $t jZI$Aj {Bt Bj }Bj${$sj JZ R {s}s9 I
sR s @N
RZ 8 t
e ? Bt s sIZ{{$? Bt I js }sjsA s $t j Rs A$jj$Bt w8$j 8$jjBt RD }B js R}sK tBjs A$jj? Bt wZt 8$jj? Bt I 8$jjBt RD =t ` 8}jB 8? sR I j stsjPsA $R8B tZ8? ${B JZ tBR $t%sI
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
1dn
7$t 8As B jB 8? sR YsA$ Zsj R JZ R st jBR R R - s R R jBR JZ }B RZ s%st9sIB sIB I %BjZ{$? Bt }BR st R $}B I }BI R _B ` 8}jB t js Ps8BRs tB% js ej `Z B I etI I ! RBt 7{B ]s I js s9s sj$ t? ts I jBR $tR { B R t 8$ s I jBR YZ8stBR }Z I R sAj { {B8Zt${s{$? Bt $tR st ? st s I 8 t s 8 t sZtJZ jBR R }s Zts st I$R st{$s Ns tB% js YsAjs t ? 8$tBR I P? R${s hj? B ${s Zts s8s $8s $ts $s JZ t jBAs tZ %sR s}B s{$Bt R {$ t ? h{sR t jsR {Zsj R R {BtR$I s js }BR$A$j$IsI I stR8$R$? Bt I js ZjB ED 7 R IB sIBR I Zts $I? t ${s $tPB 8s{$? Bt s Zts % jB{$IsI RZ} $B s js I js jZ9 w]s}? YsA$j$IsI I stR8$R$? Bt I j } tRs8$ t B s}s { t s8A$? t t j js B {B B _s $Is I R{s >i R{Z _s k d ;EH I V YZ ] ]js , et js tB% js 3ZtIs{$? Bt $8} $B >3BZtIs $Bt stI e8}$ d x1H I j {${jB I q ? st B B I js 3ZtIs{$? Bt yRss{ VR$8B% I R{ $A sj $tJZ$ st 8Z st ej 8ZjB JZ jj s ? s s BA ts j y8} $B =t R P? R${s8 t I? A$j sZtJZ I Ps{Zj sI R - sB I$ts $sR JZ R {s}s9 I ` { j {Bt Bj 8B{$Btsj I jBR R R YZ8stBR ]Zsj pB Bts % RZR B`BR JZ$%sj s 8B $ ! B ` 8}jB jB t{Bt s8BR t j hj8 5+Z? RZ{ I$? B t Bt{ R2 >+Zs 8sRR stI Y _$ d E H IBtI sR j I R{ZA $8$ t B I Zts ts% 8s {$sts k I RZ $}Zjs{$? Bt R }Zj sIs IZ st R$ jBR t j RZARZ jB jBtI$t tR js t ? s }R? JZ${s 8st t t RZ $t $B sP { s sj {B8}B s8$ t B I jBR R R YZ8stBR Vj 8s t I js ks {Z R $BtsAj -$R t{$s I R BR }BI R 8 t sj R RZj s $8} tRsAj JZ R sR YsA$j$IsI R }Z Ist } 8st { t R sIB js t sR js 8Z I jBR JZ jsR }BR t * PB 8s st? sjB s t js tB% js 3B sR B t $ s - sK ts >7 st $t s 7 st NstI d EdH I iBA V < $tj $t zsj t $t ${Ys j 78$ Y R Zt YZ8stB I s JZ Rs s js q$ s jj %stIB {BtR$ B jBR }BI R }R$? Bt${BR j sIBR }B jBR 8s {$stBR Vj ZtBR R R tB 8 tBR Pst ? sR ${BR YsA$ st R I j }jst s q$ s Yst R$IB s8A$? t IB sIBR I }BI R 8 t sj R }B sj ZtBR sZ B R I {$ t{$s h{{$? Bt et{Bt s8BR }B ` 8}jB js s9s I jBR O $ YZ8stB$I R I n 8 BR I sj Z s JZ } B{ I t RZ}Z R s8 t I Zts s8s I js %BjZ{$? Bt I$P t s js I j YB8A k JZ Z $j$9st js j }s ? s {B8B PB 8s I {B8Zt${s{$? Bt sj {B8B R R} {Zjs t j hj8 ej sAB8$tsAj YB8A I jsR t$ % R >qY VAB8$tsAj 7tBb8st d x H qsj % 9 R B tB R s 8? sR JZ Zts - s}Bjs{$? Bt h{ ${$s I Zt P t? B8 tB A$ t {BtB{$IB ? ABj R {B8B jBR sA BR I *BZ jsR {B8B R js {B8Zt${s{$? Bt 8 I$st P B8BtsR@- I sj ZtBR s 7 Ys {B8} BAsIB JZ {ZstIB Zt sA B R s s{sIB }B R{s sAs`BR B BR sA BR R$ ZsIBR s st sD st I$R st{$s RBt {s}s{ R I R s wsZtJZ %$I t 8 t tB I PB 8s $tR st ? I 8$tsIsR RZR st{$sR JZ? 8${sR JZ IZ{ t j {s ? s{ tZ $ $%B I js 8sI s k R B tst R$R t R s js }js s
7 s{B}jst 8 t R ! B I jBR s ?8A$ BR t j JZ Ys Y {YB s}s ${$? Bt j {Z RB I jBR }BI R 8 t sj R R j I js {tBjB ? s {s}s9 I }B t{$s B I Rs Bjjs t Zt PZ Z B jBR }BI R }R$? Bt${BR B ` { j {Bt Bj 8 t sj I YB8A R k 8? sJZ$tsR 3$j8 R {B8B 7s Z tB n >7s Z t n d M(H tBR s{ {st s js $I s I j {Bt Bj 8 t sj et R {sRB Zt -}jB sIB R}s{$sj Z $j$9s Zt stR8$RB {Bt { sIB s RZ { A B }s s t%$s B ? I t R s RZ BAB <? { B Ns js{$? Bt t BtIsR { A sj R k BAB R R Ys }jsR8sIB s8A$? t t js tB% js ej YB8A JZ tB -$R ? s > k Ws8 $R N $Bt d EH
NsR P B8BtsR RBt R K tsj R JZ? 8${sR BjB BRsR $8}B st R }s s j {BtB{$8$ t B k js R $8ZT js{$? Bt R -Zsj R
@-
© Los autores, 2001; © Edicions UPC, 2001.
1d;
* $t Bt s e$tR $t
3$ ; dn zst I { ? st B wV $AsD ej * ]B k BAR %s j { A B I *BtB%st j 8$jjBts $B sj {Zsj Ys $t t sIB Rsj%s js %$Is V js }BR ? R s{sAs ? s B8stIB }BR R$? Bt I RZ 8 t 3B B s8s I js } j? {Zjs *BtB%st:R {Zjs qY s$t Ys GBZjIt: s$t >d xnH wVAs`BD ]Zsj 8BI tB * 3 st, tR $t j {$ Z`stB I js } j? *$ >d x H -} $8 t s {Bt stR}jst R sZtJZ RZR { s{$Bt R RBt st YB $Aj R JZ jsR 8st $ t t R { B ]ZstIB RZ tB%$s RZj s I {s}$ sIs t Zt s{{$I t Zs Is RZ {sA 9s k AZR{s Zt {Z }B I 8}js9B
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
@N
I iB js9tk IBtI Zt stI B$I }Z I jB{sj$9s s RZR { sIB R sR stIB RZR BtIsR { A sj R qs8A$? t jBR R R YZ8stBR RBt BA` B I {Bt Bj 8 t sj AsR s Z8 t sj I Zt st t? Z8 B I } j? {ZjsR k tB% jsR et yt%sI R P B8 s R ZtBR sj$ t? tsR $8}jst st Zt { $R sj I {Zs 9B t js AsR I j { A B 8 I$st j {Zsj }Z I t ` { Zt {Bt Bj RBA {sIs YZ8stB et 3jsRY pB IBt >d M(H B _jst s } BY$A$IB R tBR 8Z R st $t Rst R 8? sJZ$tsR }s s s8}j$h{s j }B t{$sj { A sj }s s RZ ZRB t j }s ? s Z B sR ? {t${sR 8 t sj R _ B {B8B t j {sRB I js $t8B sj$IsI js RBjZ{$? Bt 8? sR I ? sR ${s }s s js $t h{$ { A BT8? sJZ$ts {BtR$R t {BjB{s Zt { A B YZ8stB t Zt {Z }B 8 {? st${B eR B R jB JZ R }jst s t qY ]kA t ${ s$tR >d E1H I isk8BtI 3 FBt R IBtI R - s Zt { A B k R $tR s t Zt B I tsIB A$B8 {? st${B et js $tJZ$ st tB% js BI st >d dH I *s%$I i Zt{Y jBR YB8A R sAstIBtst RZR t%Bj Z sR I {s t }s s s{sAs {Bt%$ $? tIBR t 8? sJZ$tsR tsR JZ }jst st I R Z$ R ZtsR s B sR {Bt AB8AsR tZ{j s R et jsR tB% jsR ]s {YbB jI >d xH I ]Y $R Bk{ k qY 7Y$} GYB 7st >d E H I Vtt {]s& k jsR } B}$sR ts% R R js R {BtR $ Zk t j {Z }B 8 ? sj${B }s s sJZ jjBR YZ8stBR JZ Yst } I$IB j RZkB ! B I jBR s Z8 t BR s s{ $%BR jB t{Bt s8BR sRB{$sIB s js $I s I j $R B I jsR BtIsR { A sj R 8$ $IsR }B Zts } RBts V8}s ? stIBR t js $t } s{$? Bt I j R$R 8s t %$BRB {B8B Zt {$ {Z$ B j? { ${B sj ZtBR sZ B R Yst RZ $IB j ZRB I R sR sAs{$Bt R }s s } {$A$ jsR 8$R8sR R tRs{$Bt R JZ js } RBts R$ t t j $tR st I RZ $R B eR }jst s8$ t B stRPB 8s sj $t -} B } B s Bt$R s I j js B ]s9s 8skB > $ ps8 <Zt d x;H I V YZ ] ]js , t Zt -} B {s sIB I %$tBR e-} $ t{$sR R$8$js R %$% t jBR } B s Bt$R sR I _ Bk { B s$tR B 8 > s$tR B 8 d MnH YsR s j - 8B I R$t Bt$9s Zts {$t s } sAsIs IBtI Zts } RBts $R ? B RZ } B}$s 8Z et js tB% js I VtI ? sZ B$R Ns 8? sJZ$ts I j jBR } tRs8$ t BR >Ns 8s{Y$t s r j$ j R } tR? R d n H R I R{ $A Zts R} {$ I {? s8s s {s}s9 I $R s jBR } tRs8$ t BR I js t t } j? {Zjs PB B ? sh{s V } Rs I JZ j } tRs8$ t B $t%BjZ{ s P t? B8 tBR j? { ${BR tB R ? s tsIs {js B R$ jsR R tT Rs{$Bt R k jBR {Z IBR tB RBt 8? sR JZ R$8}j R R ? 8ZjBR j? { ${BR NB {$ B R JZ j PZtT {$Bts8$ t B I j { A B R ? s sRB{$sIB s $8}ZjRBR j? { ${BR Ns {BtIZ{{$? Bt t %$BRs s I$P t{$s I js {BtIZ{{$? Bt t Zt 8 sj R 8Z{YB 8? sR j t s k tB %s ? s I $t tR$IsI VR? 8$ t sR js {B $ t j? { ${s t Zt Y$jB {BtIZ{ B 8 ? sj${B R I A$Is sj 8B%$8$ t B I jBR j { Bt R j$A R I j 8 sj j {Z }B YZ8stB P { ? Zs R } B{ RB Z $j$9stIB j 8B%$8$ t B I $Bt R PZtIs8 tT sj8 t }BR$ $%BR Ns t Z Bts {BtR $ Zk j j 8 t B A? sR${B I j R$R 8s t %$BRB ]BtR s I Zt {Z }B { jZjs k I$% RsR hA sR B s8$h{s{$Bt R eR sR hA sR RBt I IBR $}BRU jsR I tI $ sR JZ {$A t js $tPB 8s{$? Bt t PB 8s I R ? 8ZjBR j? { ${BR k j s-? Bt t{s sIB I stR8$ $ js $tPB 8s{$? Bt s jsR B sR {? jZjsR t %$BRsR ]ZstIB jBR R ? 8ZjBR JZ {$A t jsR I tI $ sR RZ} st Zt {$ B Z8A sj I $t tR$IsI R $t${$s Zt $8}ZjRB t %$BRB JZ R } B}s s s s%? R I j s-? Bt VR? sj jj s Zt $8}ZjRB t %$BRB s jsR s8$h{s{$Bt R 8$tsj R I Zts t Z Bts R j$A st RZR st{$sR t Z B stR8$RB sR JZ {BtIZ{ t j $8}ZjRB s jBR { } B R I js R$ Z$ t {? jZjs NsR tR$Bt R j? { ${sR $t%BjZ{ sIsR RBt I j B I t I sj ZtsR I { tsR I 8$j$%Bj $BR ej } B{ RB I stR8$R$? Bt I Zt }ZjRB s s%? R I j s-? Bt JZ R } BIZ{ R$t s tZs{$? Bt R {B8}s sAj sj JZ $ t jZ s t Zt {$ {Z$ B j? { ${B {Bt R$R t{$s k {BtI tRsIB <s{ 8? sR I Zt R$ jB JZ R {BtB{ js ts Z sj 9s j? { ${s I j R$R 8s t %$BRB ej hR$? BjB B
© Los autores, 2001; © Edicions UPC, 2001.
@-
* $t Bt s e$tR $t
sj 8? st e8$j < $t ${Y *Z B$RTi k8BtI PZ j } $8 B t I { s t dM; jsR 8$t? ZR{ZjsR I R{s sR j? { ${sR JZ R } BIZ{ t sj {Bt s jBR 8? ZR{ZjBR I j A s9B _s s jjB R %sj$? B I Zt sj%st? B8 B Zt } $8$ $%B 8 I$IB I tR$Bt R {ZkBR Y$jBR {Bt { ? B I$ { s8 t s RZ {Z }B Vj Is R {Z t s JZ js }$ j s{ ZsAs {B8B Zts As s }s s jsR R K tsj R j? { ${sR t sIsR }B js 8sRs 8ZR{Zjs $t $B tB IZI? B t sA $ R Zts Y $Is t {sIs A s9B s st{s R js }$ j $t BIZ{$ jBR j { BIBR I j sj%st? B8 B t jsR jjs sR _ZIB sR? {s} s {B $ t R j? { ${sR ZtsR $t s % { R 8? sR $t tRsR JZ js BA t$IsR t Zt } $t{$}$B gqBIB Zt {sRB I }ZtIBtB {$ t ? h{B <Bk t I? s {Bt ? {t${sR 8Zk R$8$js R k Z $j$9stIB s8}j$h{sIB R j { ? Bt${BR 8Zk R tR$Aj R }Z I t I { s R {Bt Ps{$j$IsI jBR I? A$j R $8}ZjRBR 8ZR{Zjs R eR P t? B8 tB R 8} 9? B s s} B% {Ys t jBR sK tBR R t s }s s I$R K ts } ? B R$R 8 {? st${sR {s}s{ R I BA I { s {Bt s{{$Bt R 8ZR{Zjs R p s{$sR s jjB $t{jZRB jBR $tI$%$IZBR {Bt s% R 8$tZR%sj? sR }Z I t tsj R j? { ${sR t sIsR jj s s 8st `s JZ$}BR j { ? Bt${BR w{B8B B I tsIB R D {Bt jsR R K }B RZR 8? ZR{ZjBR qs8A$? t R Yst Z $j$9sIB {Bt ? -$ B }s s R ht jsR R K tsj R j? { ${sR 8$ $IsR }B j B`B ks JZ j 8$R8B R {B8}B s {B8B Zts I? A$j As ? s j? { ${s w -$R Zts I$P t{$s I }B t{$sj t js $ts k js {? B t sD@ et R s j? t s js tB% js >GsjIBU p t$ZR $t ! A$ d ;1H I iBA V < $tj $t } R t s s Zt {$ t ? h{B 8$tZR%? sj$IB YsA$ st I Zt Rs ? j$ JZ Ys I Rs BjjsIB Zts R $ I I$R}BR$ $%BR {B8stIsIBR }B {Bt Bj 8B B JZ s8}j$h{st jBR 8B%$8$ t BR I RZR I? A$j R 8? ZR{ZjBR
GsjIB
7$t 8As B s? Zt }s { R s j `BR js s sk t $I s I js 8 t YZ8sts s Zt B I tsIB R$t t$t ? Zt $}B I $t 8 I$s $B P? R${B I 8st s JZ Zt R$8}j } tRs8$ t B AsR }s s JZ js s{ ${s ? R s JZ 8? sJZ$ts PZt{$Bt ws R 8 `st9s I j {BtB{$8$ t B I js %B9 }B B I tsIB R } ? 8}$ 9s s R ks {B8? ZtD NBR } B{ RBR 8 t sj R JZ $ t t jZ s t j { A B %st s{B8}sK tsIBR I Zts $t tRs s{ $%$IsI j? { ${s eR P t? B8 tB R s8A$? t {BtB{$IB I RI Ys{ $ 8}B Os t d 1 <stR I$B j tB8A I weepD sj $R B t }s} j I jsR 4Z{ Zs{$Bt R I js tR$? Bt j? { ${s t j { A B {s} sIsR }B j { BIBR h`sIBR sj {Z B {sA jjZIB ej st? sj$R$R I R sR R K tsj R eep Z {BtR $ Zk t R? 8$R8s Zts {$ t{$s ej { A B } BIZ{ Zt R j { B RZ $IB I BtIsR { A sj R wYsk {$t{B $}BR $8}B st RU BtIsR sjPs A s Y s I j s k 8ZD NsR I$P t R BtIsR R {s s{ $9st }B RZ P {Z t{$s w t ZtBR }B{BR Y 9$BR }s s jsR BtIsR 8Z k sj ZtsR I { tsR I Y 9$BR }s s jsR BtIsR A sD sj $ Zsj JZ Zts 8$RB s I sI$B R {s s{ $9s }B js P {Z t{$s I RZR 8$R$Bt R k R RsA JZ R ? st sRB{$sIsR s jsR I$P t R s{ $%$IsI R I j { A B w}B ` 8}jB jsR BtIsR A s RBt j RZj sIB I Zts s{ $%$IsI 8 t sj $t tRsD 7$t 8As B R Yst jB sIB 8Zk }B{BR s%st{ R s js YB s }B ` 8}jB I js{$Bts j {Bt`Zt B I BtIsR JZ j { A B 8$ {ZstIB Zts } RBts R ? s } tRstIB t Zt {Bt{ } B {Bt{ B {B8B Zts }sjsA s B Zts j s O R JZ {B8B s}Zt st jBR 8? I${BR <Z Y 7 NZR I k i t`s8$t ts}} }B j 8B8 t B jsR R K tsj R j? { ${sR I j { A B R R$R t sj {Bt Bj Ns -}jB s{$? Bt I R sR $I sR t j s ?8A$ B I js h{{$? Bt js t{Bt s8BR }B ` 8}jB t j js B >qY$t, d H I yRss{ VR$8B% 7$t 8As B Yst } B}B {$BtsIB Zt {$ B RB}B {$ t ? h{B s }BI R 8 t sj R {B8B js j }s ? s ? eR s {BtR$R $ ? s t$ 8? sR t$ 8 tBR t jsR 8 t R I $tI$%$IZBR I$R st{$sIBR 7$ j { A B R Zt 8$RB I BtIsR AsR s R$8}j 8 t {BtB{ js P {Z t{$s I RZ 8$R$? Bt k {B8B
s{B}js
j { B t{ PsjB s8s BtIsR { A sj R
geR ? s } tRstIB R$t Bt$9s
NsR } $8 sR {$A t j tB8A I R K tsj R j { B8$B ? sh{sR B e p w j tB8A } B{ I I j { ${BR 8$ $IBR }B j B`B R I tB8$tst R K tsj R $R B t }s} j I R BR $8}ZjRBRD NBR $8}ZjRBR j? j { BB{ZjB ? sh{sR B e!p
d
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
1d
3$ ; d; g]ZsjJZ$ s }Z I {BtR Z$ jB R$ R {Bt{ t s jB RZh{$ t {Bt j I$sj I Zts sI$B R j {{$Bts js@M Ns I$R st{$s t 8$RB R k { } B R wjsR BtIsR j { B8s t? ${sR R I R}js9st s Zts % jB{$IsI {BtR$I sAj js % jB{$IsI I js jZ9 sZtJZ ht$ sD k js I$h{Zj sI R K tsjsIs 8? sR s $As I $t } s R sR R K tsj R $t%sj$Ist {ZsjJZ$ $t t B I 8Zjs t j }jstB sj jsR Ys9sK tsR I {ZsjJZ$ j? }s s I js h{{$? Bt {B8B js B} sIB s I js I j }? s ${s {B8 {$sj JZ s}s { t js tB% js I iBA 7$j% A U " s <B {Y,$RR tB t? s 8? sR JZ {Bt{ t s R }Bt R t {Bt s{ B {Bt j } ? B-$8B q_ I js {sI ts I stR8$R$? Bt k t%$s tZ R B 8 tRs` >s s%? R I js I tBR j }? s ${s {B8 {$sjH JZ jj s ? s $tR st ? st s8 t s ] t sj psj? s{ ${s ws %s $BR 8$j R I sK jZ9 I I$R st{$sD"
V s%? R I Zt A$jj? Bt I sK tBR
7$ j {Bt s{ B tB R {Bt j B B - 8B I js psjs-$s R$tB {Bt j t Bt{ R tB JZ Is 8? sR 8 I$B JZ {Z $ s Zt 7 s s I Zts } RBts {Bt Zts R} {$ I }BI R j }? s ${BR {s}s9 I jB{sj$9s k {stsj$9s s s%? R I RZ {Z }B sj R}? $ Z t {Z R $? Bt Ns tZjs }Z s{$? Bt {$ t ? h{s I j R}$ $ $R8B j I tB8$tsIB }s s {Bt s{ s {Bt jBR R}? $ ZR B sj8sR I jBR 8Z BR I j 8? sR sjj? s wJZ Ys {Bt sIB {Bt $jZR R I P tRB R {B8B j R{ $ B V YZ ]Btst *Bkj B j ts Z sj$R s qYB8sR < <Z-j kD Ys 8B%$IB s sj ZtBR R{ $ B R I {$ t{$s h{{$? Bt s AZR{s Zts PZtIs8 t s{$? Bt 8 tBR 8? R ${s }s s jBR }BI R JZ R j s $AZk t VZtJZ $9stIB s? Zt 8? sR j $9B BA 7Ysb t >_sjs{ BP e t$ k d E H k e ${ 3 iZRR jj t >7 t $t jR P B8 7}s{ d xdH jj st s IB s s jsR sj8sR I {Bt t$IB P? R${B {BtR$I ? stIBjsR {B8B 8 sR PB 8sR R sAj R I t ? s et js tB% js >Ns } RR Z I R s |8 R d ndH VtI ? sZ B$R js s js Y$R B $s I Zt {$ t ? h{B JZ I R{ZA JZ j R Zt sR JZ R{s}s I j {Z }B sR js 8Z 5Vj Zts B s Y$}? B R$R2
8? I$Z8
8? sR sjj? s
}BI
] t $t jsR I j R}s{$B sj$ t B %$ sj
_sjs{$B I js t$IsI
} RB I jsR sj8sR dM
ej
et sj$IsI jsR {BRsR tB RBt st R t{$jjsR IsIB JZ jsR BtIsR Z $j$9sIsR t j {B8Zt${s{$Bt R }BR t P {Z t{$sR 8$jjBt R I % { R RZ} $B R I j B I t I j 8 sY 9$B
© Los autores, 2001; © Edicions UPC, 2001.
1dM
* $t Bt s e$tR $t
ej }BI I js PZ 9s =ts I jsR Rs sR I {$ t{$s h{{$? Bt 8? sR } Bj? h{sR t {Zst B sj ZRB I jBR }BI R I js 8 t R h R js Rs s $t${$sIs {Bt Ns Z s I jsR sjs-$sR >7 s Gs R d H eR s } $8 s } j? {Zjs tBR $t BIZ{ t j {? {ZjB I jBR {sAsjj BR F I$ 8s R BR t j {Bt Bj I js PsAZjBRs 3Z 9s et }sjsA sR I !A$ bst tBA$ Zt st $ ZB {sAsjj B I R s B I tU "Ns 3Z 9s R Zt {s8}B I t ? s { sIB }B BIB sJZ jjB JZ R ? s %$%B WBR BI s } t s t tZ R B $t $B k 8st $ t Zt$Is s BIs js sjs-$s" Z{YsR I jsR R$ Zs{$Bt R JZ tBR 8Z R st jsR I$P t R } j? {ZjsR I js }B j 8B8 t B $jB ? s R AsRst t Zt ZRB tB B BIB-B I js 8 t *s Y zsI j 8sj%sIB 7 K tB I j 7$ Y Is } $IsR 8Z R sR I j }BI I js 3Z 9sU R {s}s9 I R st Zjs s Zt Bh{$sj I j `? {$ B JZ tB Ys s{ ZsIB I$j$ t 8 t $8}ZjRs BA` BR %BjZ8$tBRBR s st % jB{$IsI s s YsR s RZ 8stB js 8}ZK tsIZ s I RZ R}sIs I jZ9 B I R%$s js sk { B $s I Zt Ys9 j? sR I$R}s sIB {Bt s RZ } RBts et ej y8} $B {Bt ss s{s >qY e8}$ 7 $, R s{, d M(H OBIs j 8s R B F I$ sh 8s JZ j s8sK tB I Zt BA` B wRZ } RB I Y {YBD tB $ t $8}B st{$s }s s js 3Z 9sU Is jB 8$R8B j %st s Zts ts% JZ s I js t$8$ IsI Zts } JZ K ts }$ I s eR RZj sIB tB }s { sI8$R$Aj wsj 8s t {js B R ? JZ RZ}Bt sI8$ $ js -$R t{$s I js } B}$s 3Z 9sD t j 8s {B I j {Bt{ } B t b Bt$stB I PZ 9s _s s j %s Zt BA` B R t { Rs $B {B8} tRs js s s{{$? Bt s%$ s B $s I j }jst s k }B st B tB RZj s jB 8$R8B j %st s Zts ts% JZ Zts }$ I s !A%$s8 t R t { R$ s Zts PZ 9s 8skB }s s 8st t t j s$ s Zt } B ? Bt JZ s Zt j { ? Bt t$ tIB } R t JZ j } B ? Bt R ZtsR d MnE % { R 8? sR } RsIB JZ R Z ?j $8B =tB I jBR I sjj R 8? sR {Z $BRBR R j JZ -Y$A j $ ? st${B e8} sIB j {Zsj 8 I$st j ZRB I js 3Z 9s RB8 sj `B% t NZ, 7,kbsj, s tZ8 BRsR I R{s sR j? { ${sR JZ }s { t RZ $ I RZR 8stBR < 8BR %$R B JZ jsR {B $ t R j? { ${sR sRB{$sIsR s jBR $8}ZjRBR t %$BRBR tB RBt I 8sR$sIB j %sIsR WB BAR st t js ts Z sj 9s -$R t st$8sj R JZ }BR t Zts {$ s R tR$A$j$IsI t js{$? Bt {Bt jBR P t? B8 tBR j? { ${BR w]ZsI B ; 1D V jB js B I js %BjZ{$? Bt sj ZtsR R} {$ R Yst I Rs BjjsIB B ? stBR R tR$Aj R s js j { ${$IsI NBR $AZ Bt R }B ` 8}jB I { st jBR } JZ K t? R$8BR {s8}BR j? { ${BR } BIZ{$IBR }B js {s s j? { ${s t s I Zt {Z }B 7 Yst P { ZsIB -} $8 t BR JZ 8Z R st JZ R P { B R j R}BtRsAj I js I {{$? Bt I } { R t sIBR As`B js s ts }B }s I jBR $AZ Bt R ej 8$R8B P { B R } BIZ{ R$ t jZ s I sj$8 t B R t $ st {s sR j? { ${sR ej $AZ ? Bt }Z I jj s $t{jZRB gs $ tB s sj$8 t B A$ t %$R$Aj ! BR } { R {B8B j pk8ts {YZR B } 9 I j W$jB Z $j$9st {s8}BR j? { ${BR }s s js I {{$? Bt I } RsR B t 8$ BR k s8A$? t {B8B RZR $ Z B I j R t $IB I js %$R$? Bt t s ZsR Z A$sR k BR{Z sR ej {s8}B j? { ${B t sIB }B R BR } { R R AsRs t js R }s s{$? Bt I js {s s Ns $t tR$IsI I j {s8}B j? { ${B }Z I R {Bt BjsIs 8 I$st { } B R R$ ZsIBR s jB js B I j {Z }B I j } 9 ej pk8ts {YZR }Z I R sAj { Zts tR$? Bt I sj ZtBR %Bj $BR t RZ {sA 9s k RZ {Bjs Ns } R t{$s I Zt BA` B {BtIZ{ B I$R B R$Bts js PB 8s I jsR j? t sR I j {s8}B j? { ${B * R s 8st s j } 9 }Z I I R{ZA $ BA` BR B {B8$Is w3$ ; dxD et {$ B 8BIB Z $j$9s j {s8}B j? { ${B }s s % t j 8s 7 }$ tRs JZ sj ZtBR } { R Yst I Rs BjjsIB R BR }BI R j? { ${BR }s s I { s jsR tR$Bt R j? { ${sR I B BR } { R =t $AZ ? Bt B Zts sks }B ` 8}jB }Z I t jB{sj$9s } JZ K tBR } { R s {B sR I$R st{$sR ! BR } { R }Z I t {Bt Bjs s
© Los autores, 2001; © Edicions UPC, 2001.
* $t Bt s e$tR $t
]ZsI B ; 1 _ { R j? { ${BR k j k I !Y8 ]$ BR } { R Yst I Rs BjjsIB {? jZjsR 8ZR{Zjs R R} {? h{sR JZ {BtR $ Zk t ZtsR }js{sR {B sR k j$RsR I tB8$tsIsR j { B}js{sR Vj R R $8ZjsIsR }B $8}ZjRBR t %$BRBR B $T $tst Zts tR$? Bt I Zts I? {$8s I %Bj $B Ns {B8A$ts{$? Bt I { t ts R I R sR }js{sR }Z I Is jZ s s tR$Bt R jB{sj8 t j %sIsR Ns st Z$js j? { ${s B ej { B}YB ZR }B ` 8}jB }Z I jj s s } BIZ{$ tR$Bt R I YsR s n(( %Bj $BR {s}s{ R I s Z I$ s Zts } Rs B t 8$ B Z{YsR I jsR j { B}js{sR R t{Z t st {Bt { sIsR t }s sj jB }s s } B}B {$Bts Zts $t tR$IsI I {B $ t RZh{$ t 8 t j %sIs }s s 8s s B s Z I$ sj t 8$ B ej B } IB tBA$j$sts Zts R} {$ I sks I s Zs RsjsIs $ t sj I IB I d ((( j { B}js{sR t R $ {B8A$tsIsR {Bt Zt B sj I ZtsR 1 ((( t }s sj jB s I$P t{$s I jsR st Z$jsR I s Zs IZj{ JZ }BR t 8? sR j { B}js{sR t R $ eR s I$R}BR${$? Bt BA I { s jsR I$P t R {s s{ ? R ${sR JZ s8ABR 8 I$BR s{ZBRBR } R t st I RI j }Zt B I %$R s j? { ${BU js R$R t{$s j? { ${s I j s Zs I$R8$tZk {Bt j sIB I Rsj$t$IsI _s s t s js 8$R8s $t tR$IsI I {B $ t t Zt 8 I$B I R$R t{$s Z8 B 8skB j? { ${s 8? sR j %sIs w{B8B j s Zs IZj{ D jsR st Z$jsR I$R}Bt t I Zt t? I j { B}js{sR {Bt { sIsR t R $ JZ } 8$ t sZ8 t s js tR$? Bt ejjB R sR? s {sZRs I js j k I !Y8 eR s j k R sAj { Zts js{$? Bt I } B}B {$Btsj$IsI t js tR$? Bt s}j${sIs k js {B $ t j? { ${s s s%? R I js R$R t{$sU tR$? Bt ) {B $ t R$R t{$s 7$ js R$R t{$s sZ8 t s s8A$? t I A Ys{ jB js tR$? Bt }s s 8st t Zts {B $ t {BtR st ]ZsjJZ$ B s I$R}BR${$? Bt I$P t YsA ? s B{sR$BtsIB js 8Z I js stT Z$js sj R RZR {? jZjsR I R Z$IsR }B j }sRB I Zts {B $ t j? { ${s j %sIs s s%? R I RZ } B}$B {Z }B %BjZt sI stI R tR$Bt R j? { ${sR JZ j R } 8$ t I { s BA` BR t RZ Y? sA$ s I s ZsR }B{B stR}s t R * R s 8st s }Z I t %$%$ t 8 I$BR Z A$BR {B8B j As B IBtI j R t $IB %$RZsj tB RZj s Z ? $j ! st$R8BR {Bt R tR$A$j$IsI j? { ${s R s % 9 $8s $ts $BR }Z Ajst jsR tZA R I j }jst s F? Z}$ t j js B et{Z t B {Bt IZRs >V $t b$ Y IZRs d 1H I V YZ ] ]js , 7Bt Zts R} {$ I 8 IZRsR I {$ t 8 BR I jBt $ ZI k d x ,$j? B8 BR I I$? s8 B JZ R I h tI t I RZR I } IsIB R 8 I$st I R{s sR j? { ${sR gI Zt 8$jj? Bt I %Bj $BR ! BR R R j? { ${BR s}s { t t 7$8A$BR$R >7k8A$BR$R d MMH }$RBI$B I js R $ I qz 7 s q ,U js tZ %s t s{$? Bt 7 s s I jBR B t $stBR YZ8stB$I R JZ Yst sIJZ$ $IB R BR }BI R }B sIs} s{$? Bt sj $t tRB {s8}B 8s t? ${B I RZ RBj ]B8B % 8BR j }BI j? { ${B I R R I R sR {s s{ ? R ${sR tB R AsRs t j k R P? R${sR tZ %sR R$tB t Zt } B{ RB %BjZ $%B JZ Ys JZ $IB 8? BIBR I sIs} s{$? Bt s Zt 8 I$B YBR $j _B st B j e8} sIB I ej B tB I j F I$ >i Z t BP Y F I$ d MnH }BI ? s I$R}s s skBR R$ YZA$ R I Rs BjjsIB sj ? Zt $}B I j { B}js{sR R I {$ } t {$ R s Zts R} {$ {Bt } BAj 8sR I Y? sA$ s B PZ R Zt ,
© Los autores, 2001; © Edicions UPC, 2001.
; 57Z K ts 3 st, tR $t {Bt B% `sR j? { ${sR2
@
R 8Z st VZt sR? }s { JZ YsR s Zts st Z$js j? { ${s R? BjB }Z I 8$ $ I R{s sR I {B s IZ s{$? Bt s I$P t{$s I jB JZ R {s}s9 I sj$9s j 8 t sIB e8} sIB wg{js B JZ }B sj B I A BR t s R st B D WB -$R t %$I t{$sR } BAs B $sR I 8Z{YBR I jBR }BI R JZ R s $AZk t s js 8 t s } Rs I JZ sj {B8B Y 8BR %$R B js ts Z sj 9s Ys RsA$IB }B t{$s B I Rs Bjjs 8 {st$R8BR sj ts $%BR s jBR Z $j$9sIBR }B jBR R R YZ8stBR }s s {B8Zt${s R B } {$A$ j t B tB ]Bt BIB tB I A 8BR Bj%$Is jB JZ 8st$P R sAs V YZ ] ]js , U "NBR }BI R ks {BtB{$IBR I js 8 t RBt st - sB I$ts $BR s sIB R k 8s s%$jjBRBR JZ tB Ysk t { R$IsI sj Zts I $t%B{s B BR tZ %BR"
© Los autores, 2001; © Edicions UPC, 2001.
x N k tIsR I Zt }jst s jjs8sIB q$ s
11n
x
N k tIsR I Zt }jst s jjs8sIB q$ s
7BA 8 s $BR %$s` BR JZ 8} tI t Zts { Z9sIs sj { t B I js q$ s RBT A 8ZtIBR I %sR sIBR }B YBjB{sZR BR tZ{j s R k $ sR st sIsR }B B{? stBR $tht$ BR
V jsR ;E p q I j dd I R } $ 8A t j % stB -{ }{$BtsjT 8 t Y 8BRB I j sK tB 1( js 8skB }s I jBR YsA$ st R I eZ B}s %$ Bt s}s { t j {$ jB B $ t sj Zts I RjZ8A st ABjs I PZ B et {Z R $? Bt I R ZtIBR RZ A $jjB RZ} ? B j I j 7Bj k sj I T R}js9s R t j {$ jB PZ I `stIB s RZ }sRB Zts BtIZjst {BjZ8ts I }Bj%B k YZ8B et sj ? Zt }Zt B RBA VZR $s {B8 t9? B s I R$t T s R } BIZ{$ tIB Zts R $ I -}jBR$Bt R st %$Bj t sR JZ 8? sR I Zt 8$jj? Bt I } RBtsR JZ Is Bt {Bt jBR B? IBR IsK tsIBR }s s R$ 8} ?R sR PZ Bt jsR sPB ZtsIsR 7 $R{$ t sR 8$j } RBtsR 8Z $ Bt k e jBR IsK tBR 8s $sj R R {sj{Zjs Bt t 8? sR I Zt A$jj? Bt I I? Bjs R _ B js }? I$Is JZ R$ t$h{? B }s s j s js Y$R B $s k js {$ t{$s RT sAs 8? sR sjj? s I {ZsjJZ$ {? sj{ZjB e s {B8B R$ YZA$ R R sjjsIB Zts st Z s k R YZA$ R } I$IB t Zts RBjs 8sK tsts _B{BR }ZI$ Bt R t $ sj ? Zt }js{ st j Y {YB I JZ 8$ t sR R I }BR$ sAs j }Bj%B I js I R Z{{$? Bt j 8ZtIB t B } R t{$s s IZ st 8 R R jBR s8st { R k B{sRBR 8? sR R}j? tI$IBR JZ R {B IsAst I RI j s,s Bs V YZ ] ]js , ]$ s {Bt is8s >i tI 9%BZR b$ Y is8s d nH
wy9JZ$ IsD ej } hj s}B{sj? } ${B I Zts Z s tZ{j s U js tZA t PB 8s I YBt B I Zts AB8As 8BtZ{j s
© Los autores, 2001; © Edicions UPC, 2001.
11;
* $t Bt s e$tR $t
ej sjAsU jBR } $8 BR skBR I jZ9 I$AZ`st Zts R$tPBt? s 8Zj ${BjB t Zts }s sI$R? s{s 8sK tsts R$t tZA R _ Bt B j RBj sA sRsIB AsK ts ? s R$t {j 8 t{$s 8 I$B }jst s 7? BjB Zts 8 s $s 8As {s{$? Bt sR s js R ? s ${s B8 ? s I j 8B8 t B ]Bt I$ R s 8stB s $t I$ $ RZ $8s ? st s s%? R I Zt 8s t {sj8s Z8AB sj V Bj? Bt Zts {$ZIsI 4B st % IsI B t? Z{j B {B8 {$sj I Zts q$ s {B8}j s8 t st sIs sR js PZR$? Bt I jBR {sRJZ R }Bjs R JZ Yst 8$tsIB }B {ZA $ js RZ} h{$ R t RZ B sj$IsI =t 8s I R? ${B j % IsI B R{ ts $B I js } j? {Zjs Gs bB jI >Gs bB jI d xH - s}T Bjs{$? Bt sj j? 8$ I j {BtB{$IB {s8A$B {j$8? s ${B 8ZtI$sj JZ s}Zt s Ys{$s Zt sZ8 t B I js 8} s Z s I j }jst s FZt B s B BR P { BR } t${$BRBR j {sj t s8$ t B I js q$ s }Bt t `sJZ js R sA$j$IsI I jsR stI R 8sRsR I Y$ jB }Bjs 7 R $8s t 1 d(@ , js {st $IsI I Y$ jB {Bt t$Is t jBR }BjBR R R =ts {st $IsI $t t sZtJZ $tRZh{$ t }s s {ZA $ js B sj$IsI I j }jst s * Y {YB j JZ$%sj t t s Zs j? JZ$Is I R Y$ jB } B%B{s ? s Zt sZ8 t B I j t$% j I jBR B{? stBR I R? BjB ;( 8 g_ 8$B }s s j Z$Bt$R s _ R s RZ P { B I %sR sIB t jsR }BAjs{$Bt R {BR sR JZ Is ? s s? Zt 8Z{Ys q$ s }B {ZA $ et js } j? {Zjs js } BAsA$j$IsI I t{Bt s Zt } K tsR{B I $ s R st -$ Zs JZ sR{Z $IBR {$ t BR I sK tBR I RI js {s ? sR BP js -$R t{$s I Zts 8? ${s q$ s R {s R Ys $ $IB t BIs Zts j k tIs 7$8}j R s Z8 t BR AsRsIBR t j } $t{$}$B I V JZ? 8 I R w]ZsI B x dD } 8$ t IZ{$ BIs%? s 8? sR I${Ys R $8s{$? BtU BIs 8sRs I Y$ jB s js I $%s wZt ${ A }B ` 8}jBD tB {Bt $AZk s sZ8 t s j t$% j I jsR s ZsR sj PZtI$ R * Y {YB R? BjB j Y$ jB } R t t j }BjB RZ I R{stRs RBA Zt % IsI B {Bt $t t U js Vt ? s $Is WB 8$tst sJZ? jBR I R8st R I Gs bB jI ej } B}$B } B s Bt$R s s $t jj s s I Rs T Bjjs ZtsR RB } tI t R A stJZ$sR I ? sR I jsR B `sR JZ j } 8$ t R}$ s As`B j 8s - sK ts 8Z s{$? Bt JZ JZ $ ? s Zts R{sjs I $ 8}B 8Zk RZ} $B sj { t ts I sK tBR Ns sZR t{$s {sR$ B sj I tZA R JZ 8Z R s js } j? {Zjs {BtR $ Zk B B }stB s8s $tR? Bj$ B t Zt 8ZtIB IBtI js {Bt $tZs $tRBjs{$? Bt I A ? s } B%B{s Zts %s}B s{$? Bt tB sAj k {Bt $tZsIs {ZksR {BtR {Z t{$sR w{B $ t R I s$ Z AZj t{$sR k P {Z t R B 8 t sR B}${sj RD }s { t {Bt sI {$ js Y$}? B R$R I Zt B{? stB } P { s8 t t {sj8s et R {s}? ZjB sAB Is8BR j st? sj$R$R I jsR tB% jsR k } j? {ZjsR JZ $tI t YB8 ts` s js q$ s tZ R B }s s? RB s9Zj <$R B $sR I %$s` R sj { t B I js q$ s I }js sR 8Z s{$Bt R Z sR k B BR I RsR R JZ s9B st RZ RZ} h{$ O I j B JZ %$ t I j R}s{$B x d _${Tt${ t j { t B I js q$ s
$ t sR js YZ8st$IsI B8s j RZ K tB I ? y{s B j %? stIBR }B t{$8s I j jBAB R k 8}$ 9s s B8s {BtR{$ t{$s I RZ jZ s t j {BR8BR Zts -$ Zs 8Z R s I jBR $t ? }$IBR %$s` BR I j Zt$% RB I js h{{$? Bt R sI t st t j $t $B I js q$ s BIs % 9 JZ jsR }BR$T A$j$IsI R I t{Bt s $ B $BR $t -}jB sIBR RBA js RZ} h{$ }s { t YsA R - $t Z$IB NsR $t{Z R$Bt R s Zt $tB RZA ? st B s s%? R I jBR }BjBR B 8 I$st RBhR ${sIBR $t t$BR 8 {? st${BR Yst R$IB sAB IsIsR s8}j$s8 t }B js j$ s Z s I j ? t B _Z I t t{Bt s R P t{$sR t js } B}$s BA s I _js ? Bt sR? {B8B t V YstsR$ZR $ {Y JZ$ t t ZtIZR
© Los autores, 2001; © Edicions UPC, 2001.
x N k tIsR I Zt }jst s jjs8sIB q$ s
N
3$ x d * }${Tt${ }B j { t B I js q$ s
7ZA st ZR
>dE;dH I R{ $A Zt 8ZtIB $t $B YsA$ sIB }B I s Bt R Vj ZtBR { ? ${BR I js j $j RBR $ t t JZ j {Bt{ } B I Zts q$ s
{$ t{$s h{{$? Bt {B8B e% 3
YZ {s {B8}s
Zt B $ t IZsj Y? A $IB I js j$ $? Bt k I jsR }R ZIB{$ t{$sR * Y {YB YsR s j R$ jB zyyy R YsA? s ZA${sIB j $th tB t j $t $B I js q$ s I 8BIB JZ sj ? Zt Bj? B B YsA? s $t{jZRB BRsIB $tR$tZs JZ js B s{$? Bt I js q$ s R I A? s s jBR $tP Z{ ZBRBR $t t BR I jsR sj8sR YZ8stsR }B R{s}s I j $th tB et dE 1 j sR ? BtB8B sj eI8BtI <sjj k RZ $ $? B JZ js q$ s R sAs {BtR $ Z$Is }B R Z{ Z sR {Bt{? t ${sR JZ t%Bj%? st Zt RBj { t sj Ns $I s I <sjj k tB s I? B t { $R sj$9s I js 8stB I sj ZtBR R{ $ B R Pst ? sR ${BR t tB% jsR {B8B
qY N$P stI VI% t Z R BP _ G$j,$tR >d xdH I iBA _sj B{, JZ ts s jsR I R% t Z sR I Zt iBA$tRBt ] ZRB Z ? t${B RZ} %$%$ t I Zt As {B s sIB }B j 8s JZ s}s { t j $t $B I js q$ s Vjj ? I R{ZA Zts s9s I R R %BjsIB R B8s s Zts I RZR 8Z` R OBZbs , }B R}BRs $ t R$ Y$`BR k 8$ts }B Rs s js RZ} h{$ R =ts I jsR R? s $ sR 8? sR }B}Zjs R R I A s NZI%$ <BjA JZ$ t t
W${Bjs$ j$8$$ $ RZA st Z8 qs8A$? t p$s{B8B
>d ;dH I R{ $A js } {Zj$s BI$R s I Zt `B% t tB Z B JZ sR } {$}$ s R sj $t $B I js q$ s I R{ZA Zt R$R 8s RBjs $t $B {sjstIB t j }jst s Ws9s ]sRstB%s }jsR8s t RZ
y{BRs8 Bt B eIbs I stI ej$9sA Y >d MMH Zts Y$R B $s {Bt IBR t$K tBR @ t eIbs I k ej$9sA Y JZ sR R t Zjj$IBR }B Zt 8s jR [ B8 s $Ast s Zt $tRBR} {YsIB I? t j $t $B I js q$ s q sR }sRs sjj? Md sK tBR j st Zts I R{ tI t{$s tB sAj U gE(( ((( } RBtsR ej {Bt{ } B I Zts q$ s YZ {s R jst9s {Bt jsR RB } tI t R B ? sR I j {s}$ ? st FBYt ]j % R 7k88 R JZ$ t t j R$ jB y jj ? B s RBj${$ s PBtIBR sj ]Bt RB I jBR eR sIBR =t$IBR }s s htst{$s Zts -} I${$? Bt sj $t $B I js q$ s
7 ? Zt RZ B ? s js q$ s R sAs {BtR $ Z$Is }B {$t{B {s}sR RP? ${sR {Bt{? t ${sR {Bt sA T
qY pBII RR BP V %s sAs >dM1 H I G$jj$s8 sIRYsb B qY 78B,k pBI B s zBks B Y ytt GB jI >d (MH I G$jj$R p B e8 RBt RBt Zts 8Z RT Z sR t jBR }BjBR WB% jsR {B8B
@
z? B ${ 8s $tB B $ $tsIB }B {B $ t R I j %sIs Z AZj t{$s
© Los autores, 2001; © Edicions UPC, 2001.
-
* $t Bt s e$tR $t 7k89Bt$s >dM1(H I
s I j $t ? R ts{$IB t js $I s I Zts q$ s YZ {s sZtJZ B s BA s
VIs8 7 sAB t Rs $ $9s %? %$Is8 t jsR - s%s st R B ? sR I 7k88 R =t Rsj B {Zsj$ s $%B t jsR ts s{$Bt R { t sIsR t jsR $t{Z R$Bt R s Zts q$ s YZ {s jB t{Bt s8BR t js R $ I tB% jsR I eI s i${ Z BZ YR RBA }BR $B 8 t sIs} sIs sj {$t {B8B YZ {s I tZ R s NZts t RZ tB% js B s I RZR { s{$Bt R j$ s $sR
_ jjZ{$Is $t${$sIs {Bt V Y es Y:R ]B >d d;H et j {B s9? Bt I js q$ s >V Y es Y:R ]B d EH
i$9stIB j $9B js $I s I Zts q$ s YZ {s jj %s sj } B}$B
t j {B s9? Bt I js q$ s >qs 9st s Y es Y:R ]B d n(HD
qY BBt sI >d 1xH 7Z BAR R$? Bt }B j 8s jj %s s st qs 9? st s %$R$ s jsR `Zt jsR I j $t $B I js q$ s wqs 9?
Z BZ YR s RZ $ js ts Z sj 9s
Ns 8skB }s I I${YsR tB% jsR Ys{ ZRB I j {Bt{ } B I Zts q$ s YZ {s {B8B 8 B % Y? {ZjB }s s j {Bt s{ B t {$%$j$9s{$Bt R I$R}s RU Zts js YZ8sts k B s JZ sAs {s Zt s8}j$B sAst${B I s9sR I RI jBR I R{ tI$ t R I js } I$Is V j? st $Is YsR s 8ZtIBR } $8$ $%BR } jsIBR I 8BtR ZBR s k e G ! BR sZ B R ZRst js Y$}? B R$R I Zts q$ s YZ {s }s s A $tIs R{ ts $BR sj ts $%BR VR?
$9B sU V _ B}Y {k
Bt$8B I >dMMdH I z s s B%$ {Y w}R ZI?
s P 8$t$R s IBtI sIj k Nst D } B}Bt Zt 8ZtIB $t $B BA tsIB }B Zts Z B}?
jBR YB8A R ks tB RBt A$Bj? B ${s8 t t { Rs $BR et {$%$j$9s{$Bt R I j $t $B _B {Bt s
qY 7 { BP Y es Y >dM H I ]Ys j R
sj jBR YsA$ st R JZ 8B st js RZ} h{$ R RZj st R I R{ tI$ t R I st $ ZsR
_jZ Bt$$s >d dxH I zjsI$8$ V !A Z{Y % Zts % IsI s ]$ {Z8}Bjs >d M;H I i${Ys I V NZ}B& B
$t BIZ{{$? Bt s js }sj Bt BjB ? s s}B s j }jst s8$ t B $ttB%sIB I Zts q$ s R? Bj$Is t js JZ j $8}s{ B I Zt {B8 s sA Zt }sRsI$9B s RZ $t $B e-$R t tB% jsR 8BI tsR JZ B8st j 8s I Zts q$ s YZ {s {B8B
<BjjBb es Y
qY
>d (H I iZIk iZ{, 7Bt {sR$ YB8 ts` R s Zts ? }B{s I js {$ t{$s h{{$? Bt
8? sR JZ Zts %$ sj$9s{$? Bt I Zt {Bt{ } B }B B B jsIB sARZ IB k j sIB sj Bj%$IB V} tsR R Yst R ZI$sIB jsR } {Zj$s $IsI R s%$ s B $sR JZ I A ? st s} {$s R I R js
V FBZ t k B Y ] t BP Y es Y >d 1xH I ]j 8 t 3 9stI$ k * s8R BP es Y stI 7,k >dM xH I j q$ s Zts RP s % IsI s8 t YZ {s WB sAj R -{ }{$Bt R s Rs tI t{$s RBt j $t $B I {s% tsR } BPZtIsR {B8B js }B}Zjs
}$Bt B ZRB I js sR Bt? sZ ${s BtR st $t e qR$Bj,B%R,k _s sj js8 t s jsR tB% jsR JZ {Bt 8}jst Zts q$ s YZ {s 8 Zts {B $ t j$ s $s {ZksR { s{$Bt R stR{Z t t
qY ]B8$t is{ >dM (H I eIbs I Zjb TNk Bt B z$s` sj { t B I js q$ s >zBks sZ { t I js q dME;H I FZj R z t
7 s s t {ZsjJZ$ {sRB I %$s` R $8} BAsAj R i RZj s $8}BR$Aj I R{ tI YsR s j { t B I js q$ s }B { ? s R ? Zt j R B {Z %sR ts Z sj R B s $h{$sj R NBR RBtI BR sj$9sIBR stsj$9stIB jsR BtIsR R? R8${sR B s} B% {YstIB jsR } Z AsR tZ{j s R RZA ? st sR tB % jst js } R t{$s I stI R R}s{$BR %s{? BR _ B sZtJZ R s R? BjB }B s9Bt R }Z s8 t P? R${sR jsR {BtI${$Bt R $8} st R Ys{ t $8}BR$Aj sI t s R I 8sR$sIB Ys{$s j $t $B I js q$ s NBR } B s Bt$R sR I R sR Pst sR? sR RZA ? st sR I A ? st RB}B s ZtsR {BtI${$Bt R - 8sR 8? sR sjj? s I RZR }BR$A$j$IsI R
Ns tB% js I z t Ys IsIB }$ s Zts $tR$ t sj ? s I sIs} s{$Bt R {$t 8s B ? sh{sR $t${$sIs {Bt z$s` sj { t B I js q$ s I 7 ZtIB I ]YB8? Bt w j jjs8sIB ? j$r R R}sK tBjD hj8 $ 8$T R$Aj 8 t } I$IB k }BR $B R sIs} s{$Bt R YB8? Bt$8sR wz$s` sj { t B I js q$ s >FBZ t k B Y ] t BP Y es Y d x H z$s` sj { t B I js q$ s >d HD
© Los autores, 2001; © Edicions UPC, 2001.
x N k tIsR I Zt }jst s jjs8sIB q$ s
11
3$ x 1 wy9JZ$ IsD W${Bjs$ j$8 {sk tIB sj $t $B I js q$ s p sAsIB I W${Bjs$ j$8$$ $ RZA st Z8 >d ;dH I NZI%$ <BjA w* {YsD qY $ Bt 8Bj js 8? sJZ$ts } PB sIB s I j hj8 et j {B s9? Bt I js q$ s >V Y es Y:R ]B d EH {Bt js JZ Zt JZ$}B I -}jB sIB R } t s t j $t $B I tZ R B jBAB "ug7? eR RsA$IB JZ j {sjB sZ8 t s t {sR$ Zt sIB }B {sIs R t s }$ R I } BPZtI$IsI As`B js RZ} h{$ I j pjBABn VYB s A$ tU sI8$ $ tIB JZ R s } B}B {$? Bt R 8st t s {BtR st ; IsIB JZ j sI$B R 8$I d x(( j ZsR js 8} s Z s -$R t t j { t B I A R RZ} $B s 1(( ((( sIBR NsR 8s $sR I j $t $B I js q$ s R Ysjjst }Z R t R sIB I sR $t{stI R{ t ks JZ t$t ? Zt 8 sj t$ j B B t$ j }js $tB t$ jsR 8? sR IZ sR B{sR R$R t sj 8} s Z s ] B }Z R t j I {YB I } Zt s R$ R }BR$Aj } t s t Zt 8 I$B R 8 `st " NsR }sjsA sR I V- j {B} B s Bt$R s I j z$s` sj { t B I js q$ s I FZj R z t 4 `st j {BtB{$8$ t B I JZ t jsR 8$tsR -{s%sIsR }B j YB8A js 8} s Z s sZ8 t s {Bt js } BPZtI$IsI sj $ 8B I d 0 ] }B {sIs n( 8 7$t 8As B R sZ8 t B sIZsj BAR %sIB { {s I js RZ} h{$ R tB R 8st $ t {BtR st s } BPZtI$IsI R 8skB R * R sR? sj k {B8B s}Zt s V- j js 8} s Z s } Bt B sj{st9s ? s j }Zt B I PZR$? Bt I jsR B{sR I j 8st B R? Bj$IB ZtBR 1!((( 0 ] PB 8sIsR PZtIs8 t sj8 t }B R$j${s BR I Y$ B k 8s t R$B 7 { JZ s ZtBR 1(( ,8 js 8} s Z s sj{st9s jBR d!E(( 0 ] k JZ sZ8 t s j t s8 t YsR s ZtBR n!((( 0 ] t js P Bt s t j 8st B k j t? Z{j B s 1! (( ,8 I } BPZtI$IsI * t B I j t? Z{j B R sj{st9st jBR E!((( 0 ] eR sR {$P sR I R{s st js %$sA$j$IsI I Zt %$s` sj { t B I js q$ s WB BAR st z t s8}s ? stIBR t j I R{BtB{$8$ t B I js ? }B{s k t js Psj s I Is BR -} $8 t sj R RBA js 8} s Z s I j $t $B I R{ $A Zt sZ8 t B I 8} s Z s
eR I {$ Zt sIB }B {sIs 1n 8 BR ej }$ P st{? R st $ Zs Zt$IsI I 8 I$Is I js jBt $ ZI JZ$%sj s ( n1; 8 BR ; E n ( ,8 n
© Los autores, 2001; © Edicions UPC, 2001.
11M
* $t Bt s e$tR $t
3$ x n wy9JZ$ IsD ej } BP RB N$I tA B{, k RZ RBA $tB V- j I R{ZA t js $tR{ $}{$? Bt ? Zt${s I V t V8ZIR t Aj R ABRJZ R I R sR $ st R JZ }Z Ajst sj $t${$s RZ $t{Z R$? Bt }B j { ? s I j %Bj{? st 7t & jR w* {YsD yt{ ? j $t $B I js q$ s p sAsIBR I z$s` sj { t B I js q$ s >zBks sZ { t I js q dME;H I FZj R z t RZ8s8 t 8BI sIB I {s s s s st $9s js AZ ts RsjZI I RZR $t ? }$IBR -}jB sIB R VR? s Zts } BPZtI$IsI I d( ((( }$ R R I {$ s n!1;( 8 As`B j t$% j I j 8s js 8} s Z s JZ t{Z t s js -$ Zs -} I${$? Bt R I R? BjB dx 0 ] O s dE j ZsR I } BPZtI$IsI ZtBR ( ,8 js 0 8} s Z s R I R? BjB 1 , E ] Zt {j$8s {sR$ 8 I$ ? st B ! B I jBR P { BR JZ PB 9BRs8 t I A ? st tB s jBR %sj$ t R %$s` BR t RZ {s8$tB Ys{$s j { t B I js q$ s R ? s j sZ8 t B I js I tR$IsI I j s$ et js tB% js I z t j } BP RB N$I tA B{, k RZ RBA $tB V- j 8st $ t t js R$ Z$ t {Bt% Rs{$? Bt s ( ,8 I } BPZtI$IsIU "uyt{jZRB R R$ t {$ B }js{ t Rs s 8? BRP s 8? sR I tRs 5<s tB sIB ZR I js $t tR$IsI {Bt JZ R } B}s s sJZ? j RBt$IB2 uWs Z sj8 t =t RB IB s{sAs ? s }B B? sJZ? 8s s%$jjBRs8 t u_ B R$t IZIs Rs I tR$IsI $ ? s t sZ8 t B u7? R ? Zt Zts j k tB 8Zk A$ t I 8$tsIs eR {$ B s8A$? t JZ js $t tR$IsI I js s% IsI $ ? s I$R8$tZk tIB s 8 I$Is JZ I R{ tIs8BR ]B8B RsA R R t js RZ} h{$ IBtI 8? sR R I `s R t $ RZ s{{$? Bt t st B JZ t j { t B I js
© Los autores, 2001; © Edicions UPC, 2001.
x N k tIsR I Zt }jst s jjs8sIB q$ s
q$ s jBR BA` BR tB } Rst tsIs uNB R? _ B I? s8 5tB s{sAs ? s R s$ sIJZ$ $ tIB js I tR$IsI I j s Zs2 u7$t IZIs As`B Zts } R$? Bt I d( s 8 u5O 8? sR sAs`B2 u ? sR sAs`B js I tR$IsI R ? s s? Zt 8skB u5]? B8B I R{ tI 8BR t Bt{ R2 u 8BR }$ I sR t tZ R BR ABjR$jjBR uq? B $ t ZR I R}Z R s }s s BIB WB 8 s %? s $ 8? sR sI jst t j {s8}B I jsR Y$}? B R$R }B JZ I Ys{ jB YsA ? s I B}s {Bt sj Zts $8}BR$A$j$IsI JZ tB }BI ? s }B 8 tBR I Rs{s sj } BP RB I RZR {sR$jjsR e s %$I t R$t 8As B JZ j s$ As`B Zts } R$? Bt JZ }BI ? s sj{st9s 8$jjs R I s 8? BRP sR 8$ts ? s }B RBj$I$h{s R k t Bt{ R sZt sI8$ $ tIB JZ tZ R BR {Z }BR }ZI$ R t R$R $ jB YsA ? s8BR I I t tBR } R s BIBR jBR s9Bts8$ t BR I j 8ZtIB " ]ZstIB tBR RZ8 $8BR t jsR } BPZtI$IsI R 8s $tsR js } R$? Bt }B I As`B I js RZ} h{$ I js q$ s sZ8 t s s {sZRs I j } RB I j s Zs JZ R t{Z t s }B t{$8s et j z$s` sj { t B I js q$ s R sZ8 t B R 8Z{YB 8? sR I ? sR ${B }B JZ js I tR$IsI I jsR B{sR R ZtsR n % { R 8skB JZ js I j s Zs ej $t{ 8 t B I js } R$? Bt tB R j$t sj 7$ } R{$tI$8BR I js I$R8$tZ{$? Bt t j } RB I js {BjZ8ts I s$ I A$Is s jsR %s $s{$Bt R I js s% IsI {Bt js } BPZtI$IsI s ( ,8 I js RZ} h{$ R js } R$? Bt s 8BRP? ${s JZ$%sj s ZtsR E 1M( % { R js } R$? Bt s 8BRP? ${s t js RZ} h{$ R d s 8 V ZtBR d ((( ,8 I } BPZtI$IsI js Z{j B !A%$s8 t R P { B tB } R$? Bt sR{$ tI s nM( ((( s 8 k sj{st9s n ; d(E s 8 t j t? R ? s st tB sAj t j $t $B I Zts {s%$IsI JZ s s% Rs s js q$ s YsR s RZ { t B I A$IB sj } RB 8 tB I js {BjZ8ts I s$ R} { B sj I jsR B{sR I j $t $B I js q$ s 7$t 8As B jBR 8 s $BR %$s` BR I A ? st Ys{ P t s Zt sZ8 t B I js I tR$IsI I j s$ $ t sR BRP sRD RZ sZ8 t B {Btjj %s ? s js } R$? Bt tB R s I 8sR$sIB stI wsj ZtBR { t ts R I s 8? s8A$? t Zt sZ8 t B I js I tR$IsI _ B s stI R } R$Bt R s8AsR 8s t$ ZI R I `st I R I$ { s8 t } B}B {$Btsj R V js } R$? Bt I ;(( s 8 js I tR$IsI I j s$ R ndx % { R 8skB JZ js I tR$IsI t {BtI${$Bt R tB 8sj R wd n , 8n D s d x(( s 8 j Ps{ B sR{$ tI s xdn ej s$ sj{st9s js I tR$IsI I j s Zs s Zts } R$? Bt I n ((( s 8 tB s d( s 8 {B8B R ts s t j }? s sPB {$ sIB ej {$ t ? h{B I js tB% js I z t R} s ? s t %stB sj{st9s Zts } BPZtI$IsI IBtI RB PZ s }BR$Aj ! ! ! , , b 3 3
NsR 8? s-$8sR } BPZtI$IsI R I } PB s{$? Bt I js {B 9s R {BtR Z$IsR t }B9BR } Bj? T P BR s} tsR RBA }sRst jBR d( ,8 NBR tZ %BR 8? BIBR I } PB s{$? Bt I Rs BjjsIBR }B $t t$ BR ZRBR }$Bt BR t R {s8}B Yst I `sIB BARBj B j R$R 8s sI${$Btsj AsRsIB t j 8B%$8$ t B B s B $B I Zt sjsI B 7 s s I % IsI BR {BY R } PB sIB R JZ R %st JZ 8stIB s 8 I$Is JZ } t st t jsR t sK tsR I js q$ s et {$ s 8st s RBt R 8 `st R s Y $ Bt 8Bj js ts% T} PB sIB s $8s $tsIs }B eI s i${ Z BZ YR t V Y es Y:R ]B _ R s jjB R s8BR BIs%? s j `BR I } t s 8? sR } BPZtIs8 t }s s -}jB s k -}jB s j { t B I js q$ s qBIBR jBR 8s $sj R k I$R}BR$ $%BR {BtB{$IBR tB }Z I t Ys{ tsIs st jBR P { BR {B8A$tsIBR I jsR tB 8 R } R$Bt R k 8} s Z sR $8} st RU jBR 8 sj R R PZtI$ ? st k R {Bt% $ ? st t tZ %BR 8s $sj R 8Z{YB 8? sR I tRBR V} tsR
© Los autores, 2001; © Edicions UPC, 2001.
1n(
* $t Bt s e$tR $t
}BI ? s8BR 8st t sA$ B Zt s Z` B j $ 8}B RZh{$ t }s s s s% Rs jB ! B ` 8}jB I $t{Z R$? Bt s js q$ s }B Zt ? Zt j R 8Z R s t j hj8 Ws%$ s B >d MMH JZ ts s js Y$R B $s I Zt t$K tB t }j ts }$I 8$s I js } R JZ t j sK tB dn;M s9B s j }s? R I ]Z8A $s !AR R$BtsIB }B js %$R$? Bt I Zts {$ZIsI { j R {BtR$ Z {Bt% t{ s {Zs B YB8A R }s s JZ j s{B8}sK t t sj { t B I js q$ s %$s` JZ jj %s s ? 8$tB s s%? R I j ? Zt j JZ %st -{s%stIB {Bt js skZIs I Zts - sK ts 8? sJZ$tsU j %$s` sj $t $B I js q$ s R {Bt%$ t Zt $t R} sIB %$s` 8}B sj sj R$ jB ! BR $t t BR I } PB s js q$ s } B%B{st P { BR 8Z{YB 8? sR I s8? s ${BR 5<s{$s j ht I j 8ZtIB2 >] s{, $t Y GB jI d ExH ts s j $t{ ? Aj } Bk { B {$ t ? h{B I j * 7 }Y t 7B tR tU } PB s js q$ s {Bt Zt {BY }s s - s jsR R %sR t ? ${sR I j t? Z{j B ej -} $8 t B Psjjs k `Zt B s jBR {BtR$ Z$ t R 8B BR k {s s{j$R8BR %s $BR Zts {BjBRsj $ s { Z9s js q$ s NBR $t t BR }B I t RZ s%st{ 8 I$st -}jBR$Bt R tZ{j s R R{$tI t Zts }B {$? Bt I j jBAB JZ R jst9sIs sj R}s{$B {Bt%$ $? tIBR t Zts R ZtIs NZts O sJZ? tB Ys }sRsIB tsIs 7$ I `s8BR s Zt jsIB jBR }B9BR I } PB s{$? Bt jsR } BPZtI$IsI R 8? s-$8sR IBtI Yst } t sIB jBR } B}$BR YB8A R jBR 8$t BR tB %st 8? sR sjj? s I jBR n B ; ,8 <s R$IB t jsR $t8 R$Bt R t j 8s IBtI j YB8A Ys {BtR Z$IB s{ {s R 8BI R s8 t sj { t B I js q$ s yt t$BR R${B RZ$9B VZ ZR _${{s I wdMM;Td E1D sj{st9? B j 8BI tBR {B8B j As $R{sPB w{Bt j JZ j P? 1n I t B I d E( j PBtIB I js PBRs I jsR s $stsR js 8skB } BPZtI$IsI I j 8ZtIBD B tB d xM P { Z? B jBR RZA8s $tBR } B}ZjRsIBR }B t ? s s ? B8${s w{B8B j WsZ $jZR JZ t j sK RZ8 $IB js s% R? s I jBR Y$ jBR }Bjs RD Yst Y {YB sj$IsI jsR { s{$Bt R I jsR Pst sR? sR j$ s $sR I G jjR k z t ej Y? B I js ts s{$? Bt I G jjR et j sA$R8B >yt Y VAkRR dM EH R RZ8 YsR s Zts } BPZtI$IsI I M ,8 t Zts RP s I s{ B R$t {sAj R IB sIs I Zt jsR ej Pst ? sR ${B RZA8s $tB WsZ $jZR I j {s}$ ? st W 8B JZ z t I R{ $A t z $t 8$j j ZsR I %$s` RZA8s $tB >z$t 8$jj j$ Z R RBZR j R 8 R dM (H R {s}s9 I As`s YsR s jBR d( ,8 et Zts B{sR$? Bt $t{jZRB sj{st9s Zts } BPZtI$IsI - sB I$ts $sU gdE ,8 WB R {BtB{ Zts } BPZtI$IsI {B8B ? R s t t$t ? Zt B{? stB R ej B I z t I A s $AZ$ R s jBR {BtB{$8$ t BR I js ? }B{s t JZ R R{ $A$? B js tB% js NBR } B{ I$8$ t BR $8} P { BR k ZI$8 t s $BR Z $j$9sIBR }s s 8 I$ js } BPZtI$IsI I jBR s{{$I t R 8s $tBR {BtIZ{? st s %sjB R 8Zk RZ} $B R s jBR sj R 7 ? Zt -}j${s j P? R${B O _ j8st jsR RBtIsR Z $j$9sIsR $Ast s sIsR {Bt {Z IsR I {? st Ks8B ej B9s8$ t B {Bt j s Zs B{sR$BtsAs JZ s stI R } BPZtI$IsI R js RBtIs tB R YZtI$ s 8? sR } R s JZ R I `s s $ 8? sR {Z Is VR? IsAs js $8} R$? Bt JZ js } BPZtI$IsI s 8Z{YB 8skB JZ js sj * BIBR 8BIBR s Zts } BPZtI$IsI {B8B ? R s js } R$? Bt I A ? s R I d!E(( s 8 RZh{$ t }s s s}jsR s j RZA8s $tB R$ tB PZ s }B JZ {B8B -}j${s z t }B AB{s I j } B s Bt$R sU "7$ tZ R B ts%? B tB Z%$ s js R$R t{$s I Zt {Z }B I PZtI${$? Bt 8s{$9B js } R$? Bt jB s}jsR s ? s t j s{ B" =t {Z $BRB ` 8}jB I R P { B s}s { t js {BtB{$Is R $ I j %$R$? Bt z$s` sj PBtIB I j 8s >zBks B Y B B8 BP Y 7 s d E;TEMH IBtI Zts } R {Z{$? Bt t IBR RZA8s $tBR j Zj s8BI tB 7 s%$ b k Zt ts%? B t 8$ B 8$ts {Bt js -}jBR$? Bt I j R ZtIB sj R RB8 $IB s Zts } R$? Bt 8? sR sjj? s I RZR j? 8$ R 7$t 8As B j -{ RB I } R$? Bt I A ? s } B%B{s I t sIs %? sR I s Zs }B jBR }Zt BR 8? sR P ? s $j R I j RZA8s $tB wjsR Zt$Bt R } R t R t js R Z{ Z s }B ` 8}jBD NBR BA` BR $ tI t s s}jsR s R As`B j P { B I Zt sZ8 t B I js } R$? Bt Ns -}jBR$? Bt I j hj8 8Z R s j ZRB I Zts 8sJZ s I RZA8s $tB s js JZ R {BjB{? B Zt R$8}j -}jBR$%B t Zt 8? sR JZ I$R{ B P { B R} {$sj V? Zt } B sR P s 8 t s s{{$I t sj8 t
© Los autores, 2001; © Edicions UPC, 2001.
x N k tIsR I Zt }jst s jjs8sIB q$ s
1nd
]ZsI B x d ej } $t{$}$B I V JZ? 8 I R V JZ? 8 I R w1M T1d1 s ] D PZ JZ $IB }s s I 8$ts R$ Zts {B Bts {BtR Z$Is t YBtB I j k < ? Bt yy R sAs Y {Ys I B B }Z B B R$ } R t sAs sj ? Zt $}B I sj s{$? Bt {Bt 8 sj R I $tP $B {sj$IsI _s s jjB V JZ? 8 I R I A? s I IZ{$ js I tR$IsI I js {B Bts R$t I R Z$ js Ns {BtB{$Is j k tIs R$ ? Zs s V JZ? 8 I R t j $t $B I Zts AsK t s {ZstIB {$A$? B js $tR}$ s{$? BtU geZ ,s T -{js8? BT 7Z {? j A } $t{$}$B R tZt{$s I${$ tIB JZ BIB {Z }B }s {$sj B {B8}j s8 t RZ8 $IB t Zt 4Z$IB -} $8 t s Zt 8}Z` sR{ tR$Btsj $ Zsj sj } RB I j 4Z$IB I RsjB`sIB eR } $t{$}$B -}j${s js I$R8$tZ{$? Bt s}s t I j } RB I jBR {Z }BR RZ8 $IBR t s Zs sj ZtsR }js{sR I Y$ jB }Bjs j 7 s%$ b I A Ys{ P t s Zts $t tRs jjZ%$s I {sR{B R I Y$ jB JZ Ys{ t 8 jjs t j {sR{B I j RZA8s $tB ]Bt s $s8 t s jB JZ }s { $tI${s j Bj$IB R 8? sR I tRB JZ Zt j? JZ$IBD j Y$ jB R 8 tBR R t $IB {B8? Zt wRZ j } tRs R JZ Zt R? I tRB JZ j s Zs j? JZ$Is <s{ 8Z{YBR R$ jBR V JZ? 8 I R jj ? B s js {Bt{jZR$? Bt JZ jBR BA` BR 8? sR j$%$stBR 4B st sj RZ8 $ R t 4Z$IBR I 8skB I tR$IsI * Y {YB {ZsjJZ$ s JZ Ysks B8sIB sj Zts % 9 Zt P R{B RsA JZ jBR {ZA$ BR I Y$ jB tB R YZtI t t js A A$Is x 1 <BjB{sZR BRU I j 8ZtIB I sI s- sj $t%$ tB tZ{j s
Ns t ? s s ? B8${s k RZ ZRB }B t{$sj t js PsA ${s{$? Bt I s 8s8 t B {BtR $ Zk t Zt {js B ` 8}jB I st ${$}s{$? Bt I j {s ? s{ R} {Zjs $%B k } I${ $%B } B}$B I js {$ t{$s h{{$? Bt =t js B }$Bt B qY ] s{, BP *BB8 >dM xH I iBA ] B8$ s}Zt sAs ks jBR } j$ BR I $%sIBR I sj B R 8 `st s js t ? s s ? B8${sU RZ } B s Bt$R s Zt {$ t ? h{B jB{B I {$I? s - B R$Bts sj 8ZtIB sR {BtR Z$ Zts AB8As {ZkB }BI I R Z{ $%B YsA? s R$IB } BAsIB 8$j R I sK tBR st R t Zt -} $8 t B JZ YsA? s I R s`sIB j JZ$t B }jst s I j R$R 8s RBjs gIstIB B $ t h{B < p G jjR t qY GB jI 7 3 sj {$t Z ? Bt I sR B$I RN ! BR sZ B R {B8B j } Bj? >d d;H } BPZtI$9st t j jsIB BR{Z B I js {tBjB ? s tZ{j s U j ZRB I AB8AsR tZ{j s R k RZR P { BR t ? 8$tBR I {Bt s8$ts{$? Bt s8A$ t sj k B{sRB I js {$%$j$9s{$? Bt NBR ZRBR }s{? h{BR t }s ${Zjs RZ s}j${s{$? Bt {B8B PZ t I t ? s }s s %$s` R R}s{$sj R YsA? s R$IB ks s}Zt sIs }B ps _ 7 %$RR t V ]BjZ8AZR BP 7}s{ >d ( H FBYt G ]s8}A jj wd d(Td dD R{ $ B k I$ B tB s8 ${stB I $t4Zk t R %$R sR I j ? t B {B8B VR BZtI$t 7{$ t{ 3${ $Bt k I R{ZA $IB I sj t BR {B8B yRss{ VR$8B% V e %st zB B qY BIB 7 Z Bt % ? s }ZAj${sIB t d n( RZ } $8 js B GY t Y V B8R 3s$j I >d n(H Zts Y$R B $s { t sIs t js j$A s{$? Bt I js t ? s sj8s{ tsIs t js 8s $s 7Z $t ? R }B j 8s } BR$ Z$? B {Bt js }ZAj${s{$? Bt I I$% RBR tRskBR RBA js t ? s s ? B8${s t js {$ sIs %$R s VR? {ZstIB j jst9s8$ t B I js } $8 s AB8As s ? B8${s RBA <$ BRY$8s t sJZ j Ps ? I${B E I s BR B I d ;x {Bt8B{$Bt? B s js B}$t$? Bt }? ZAj${s ]s8}A jj R t{Bt sAs V Z8 t B }s {$IB sj I < I BR I jsR R jjsR >ytY $ Y 7 s R d H I Fs8 R _ <B st IBtI j tP t s8$ t B t IBR s9sR - s R R } B%B{s sR$8$R8B js I R Z{{$? Bt I j JZ$t B }jst s {Bt $I? t ${sR $8}j${s{$Bt R t js ? t R$R I j {$t Z ? Bt I sR B$I R N
© Los autores, 2001; © Edicions UPC, 2001.
1n1
* $t Bt s e$tR $t
-Zj st }B YsA st ${$}sIB j }BI }B t{$sj I j s ? B8B I RI jsR }? s $tsR I Zts 8BI R s %$R s I h{{$? Bt iBA V < $tj $t B B I jBR I R{ZA $8$ t BR I ]s8}A jj YsA? s Z $j$9sIB ks Zt $}B I }Bj%B sI$s{ $%B {B8B s 8s t 7BjZ $Bt =tRs $RPs{ B k >d ;dH sZtJZ PZ ]j % sR s jBR R %${$BR ]s 8$jj JZ$ t RB } tI$? B s jBR {$ t ? h{BR I NBR Vjs8BR wk }BR$Aj 8 t 8? B8${s B} s $%s et * sIj$t I R Z $IsID t }j tB P t $R8B }B I Rs Bjjs Zts AB8As s ? >d ;;H ]s 8$jj st ${$}sAs js PsA ${s{$? Bt I Zts AB8As s ? B8${s Zt sK tB st R I RZ jst9sT 8$ t B {B8}Z R s }B j$ $B k I Z $B j 8 t BR JZ }BR $B 8 t PZ Bt 8}j sIBR t js AB8As I PZR$? Bt 8BtZ{j s qsj PZ j %Z jB {sZRsIB }B js }ZAj${s{$? Bt I * sIj$t JZ j 8$R8? R$8B 3 y $t% R $ ? B j }BR$Aj s{{ RB I ]s8}A jj s IB{Z8 t BR R { BR $t{jZRB PZ %$R$ sIB t RZR Bh{$tsR I VR BZtI$t }B PZ 9sR ZA ts8 t sj R ej Y 8 $R8B I js ? }B{s s sj JZ %s $BR {? B8${R JZ Ys{? st P t{$s sj 8s PZ Bt { tRZ sIBR q sR j jst9s8$ t B I jsR IBR AB8AsR s ? B8${sR JZ s sRs Bt <$ BRY$8s k Ws sRs,$ js {$ t{$s h{{$? Bt {B {Bt PZ 9s j R $ B I Zts tZ %s j? t s s Z8 t sj JZ sAstIBts jBR RPZ 9BR ZjB 1D k R { t s t jBR P { BR I RZ jst9s8$ t BU 8Z s{$Bt R }B {BtR Z$ s 8sR w]s}? I RsR {Bj? B ${B $t{jZRB j } RZt B I Rs BjjB I }BI R 8 t sj R wI Y {YB Zts PB 8s I 8Z s{$? BtD * R}Z? R I js yy pZ s ZtI$sj js YZ8st$IsI B8s {BtR{$ t{$s I RZ }B t{$sj I sZ BI R Z{{$? Bt k j I$P? {$j JZ$j$A $B tZ{j s R }jsR8s s8A$? t t $tht$IsI I s Z8 t BR -}jB stIB Zts % 9 8? sR Zt ks{$8$ t B %$ t j tZ %B hj? Bt RZ $IB sj s8}s B I Zt tZ %B I T R{ZA $8$ t B {$ t ? h{B 3$j8 R {B8B ej I? s I R}Z? R >qY *sk VP d MnH % IsI B P t? B8 tB I 8sRsR JZ 8BR sAs jBR P { BR I Zts {BtP Bt s{$? Bt tZ{j s t jsR IBR stI R }B t{$sR tZ{j s R I j R$ jB jBR eR sIBR =t$IBR k js - $t s =i77 4 `st js st ZR $s I js ? }B{s j 8B s Zts tZ %s uk I ht$ $%su Z s 8ZtI$sj JZ } j? {ZjsR {B8B js 8? ${s ej $ 8}B t RZR 8stBR >qY q$8 s{Y$t d E(H YsA? st ks } Rs $sIB- et q 8$ts B 1U j FZ${$B 3$tsj >q 8$ts B 1U FZI 8 t *sk d dH jBR I R8st R } BIZ{$IBR }B j 8$Aj B I tsIB 7,kt k RZ YB8? BjB B ZRB {Bt jBR R} { $%BR s R tsj R tZ{j s R I R t{sI tst j 1 I s BR B I d Zts Z s tZ{j s U n ((( 8$jjBt R I 8Z R k j ? t R$R I Zts $t 8$tsAj As sjjs t jBR RZ} %$%$ t R YZ8stBR k jsR 8? sJZ$tsR I j PZ Z B _B RZ js s8 ts9s Ys } R{ $ B ]Bt j ht I js yy pZ s ZtI$sj k t }s sj jB {Bt jBR ZRBR 8$j$ s R I js t ? s s ? B8${s jsR } $8 sR { t sj R tZ{j s R 8}$ 9st s }BAjs js q$ s WB% jsR {B8B W %$BR >W % R d ;1H I N R I j i k B hj8 R 8? sR {$ t R {B8B ej R? tI B8 I ]Y$ts >qY ]Y$ts 7ktI B8 d H sAB Ist tZ R BR 8? sR } BPZtIBR 8B R RBA Zts {s ? sR BP tZ{j s st ${$}stIB s{{$T BjB Zt 8 R I R}Z? R I j R tB I I t R {B8B j I js { t sj I qY $j yRjstI wgs{s {$IB R? j A I ]Y tBA$j JZ j 1E I sA $j I d ME }ZRB ej R? tI B8 I ]Y$ts D B j $R 8 t {? t `sJZ s %s $BR }s? R R Z B} BR =ts tB% js ]Y tBAkj >d M H I 3 I $, _BYj I R{ $A j I s8s YZ8stB %$%$IB t js { t sj * Y {YB Zt hj8 sj 8? st st $B s js yy pZ s ZtI$sj g! B >pBjI d n;H } B%B{s ? s sK tBR 8? sR s I } B{Z}s{$? Bt t j R tB I jBR sj$sIBR t{s stIB s RZR 8 `B R P? R${BR j -s8 t I j
Ns % R$? Bt {$t 8s B ? sh{s I js tB% js Ns 8? sJZ$ts I j $ 8}B >qY q$8 s{Y$t dM xH s{ Zsj$9s jBR jst{ R A? j${BR s}Zt sIBR ks }B < p G jjR $t{B }B stIB j I Rs BjjB I jsR IBR Z sR 8ZtI$sj R VR$8$R8B R} {Zjs {Bt Zts { s {BtP Bt s{$? Bt 8ZtI$sj t d EE t js JZ Zt s ? Bt$ B %$s` B I j $ 8}B sR$R {B8B R $ B I -{ }{$? Bt s js 8s $sj$9s{$? Bt I j 8B s ? B8${B
-
© Los autores, 2001; © Edicions UPC, 2001.
x NÂ&#x201A;kÂ&#x201A;tIsR IÂ&#x201A; Zt }jstÂ&#x201A; s jjs8sIB q$Â&#x201A;Â&#x201E;Â&#x201E;s
1nn
3$ x ; ej YBÂ&#x201E;Â&#x201E;BÂ&#x201E; IÂ&#x201A; <$Â&#x201E;BRY$8s Â&#x201E;Â&#x201A;%$R$ sIB 3B B Â&#x201E;s8s IÂ&#x201A;j hj8Â&#x201A; ej I? s IÂ&#x201A;R}Z? Â&#x201A;R >qYÂ&#x201A; *sk VP Â&#x201A;Â&#x201E; d MnH
Š Los autores, 2001; Š Edicions UPC, 2001.
1n;
* $t Bt s e$tR $t
RBhR ${sIB s{ B tZ{j s JZ s}s { t j hj8 w t Zt $t t B I s% $ Zs jBR {BtB{$8$ t BR JZ t 8s $s tZ{j s }BR ? s j AstIB sj 8? stD Ns } j? {Zjs R Zts {Z $BRs jZ{ZA s{$? Bt sjJZ$8$R s RBA js BA t{$? Bt I B B s }s $ I }jB8B 8 I$st Zt s{ B tZ{j s eR {$ B JZ I 8$tsIsR s{{$Bt R tZ{j s R } 8$ t stR8Z s sj ZtBR j 8 t BR JZ? 8${BR s js ZRst9s I js 8? ${s
}$ I s hjBRBPsj JZ AZR{sAst {Bt sY? t{B jBR st $ ZBR sjJZ$8$R sR I js IsI
8 I$s et }s ${Zjs I 8$tsIsR s{{$Bt R tZ{j s R } 8$ t t s B B s $h{$sj8 t =ts I jsR }BR$Aj R %? sR R j 8 {Z $BTd JZ sR sARB A Zt t Z ? Bt Is jZ s s Zt t? Z{j B I B BTd k s js 8$R$? Bt I Zt } B ? Bt Nj sIB s R }Zt B ZtB }BI ? s R t $ R t sIB s sAstIBts js j { Z s I R j$A B k }s $ s js {B8} s I 8 {Z $BTd g_ B s Zs I JZ $IB j { B ej } B{ RB I BA t{$? Bt I B B 8 I$st R 8 {st$R8B sR? {B8B RZ R }s s{$? Bt I j -{ I t I 8 {Z $B R BIs%? s 8? sR {s B JZ j {BR YsA$ Zsj I j B B _B B B jsIB jBR R BIB j B B $R? B B}BR I B B BA t$IBR s $h{$sj8 t RBt sI$s{ $%BR }B jB JZ }B{B I R}Z?
R sIB B $ $tsj {B8B 8 {Z $B ej } B}$B yRss{ VR$8B% sAB I? B j 8$ B I js sjj$ts I jBR YZ %BR I B B t RZ js B _s ? I PB$ sR AsR? stIBR t I 8$tsIsR s{{$Bt R B8s RZ tZ{j s R JZ $ t t jZ s t j $t $B I Zts s% gJZ B} s {B8B Zt } JZ K tB s{ B tZ{j s } B{ RstIB B-? tBTdM YsR s BA t B BTd ej B BTd R I Y {YB Zt $R? B B}B R sAj JZ }Z I BA t R 8 I$st js stR8Z s{$? Bt I j }js $tBTd sj {s} Z s 1 } B Bt R <sAjstIB I $R? B B}BR j }jB8BT1d tB R 8Z{YB sh 8s j BAB
8? sR j$ B JZ j }jB8B B I$ts $B sj k {B8B iBAAk t j hj8 _jst s } BY$A$IB >3B A$II t _jst d xEH NBR $R? B B}BR I Zt
j 8 t B JZ? 8${B I$h t t j t? Z8 B I t Z Bt R JZ }BR t jBR t? Z{j BR s ? B8${BR 8$ t sR {BtR %st j 8$R8B t? Z8 B I } B Bt R M1 t R {sRB ej $R? B B}B 1d I j }jB8B PsA ${sIB }B j BAB $ t }Z R dnx t Z Bt R k M1 } B Bt R k R Zt x0 8? sR } RsIB JZ j }jB8B 1( j $R? B B}B 8? sR {B8? Zt g!`B sj Is B
iBAAk
7Z K tBR sI$s{ $%BR et jBR sK tBR {$t{Z t s jBR R{ $ B R k Z$Bt$R sR I j ? t B 8}$ 9st s 4 `s js { {$ t } BT {Z}s{$? Bt RB{$sj }B jBR }BR$Aj R P { BR I js sI$s{ $%$IsI sR? {B8B j 8B s Zt YBjB{sZR B tZ{j s =t hj8 s` tB s js {$ t{$s h{{$? Bt
ej A RB 8B sj
>d xxH $tR$t? Zs ks jBR t PsR BR
P { BR I js sI$s{ $%$IsI i 4 `B I j R t $8$ t B I {Zj}s tB s8 ${stB }B <$ BRY$8s k Ws sRs,$ RZ t jsR Zts %s $st I jsR
8BtR 8B%$ R jsR
B } j? {ZjsR I 8BtR ZBR JZ {BtR $ Zk t Zt t -B
I Zt$? Bt {Bt js st ZR $s I Rs sIs }B j } j$ B tZ{j s et Fs}? Bt }B RZ }s s}s {
8BtR 8B%$ R
,s$`Z $ s
8 ? sPB sR ts{$IsR sj s8}s B I j IBjB I j
YBjB{sZR B % IsI B 8Z R s $B I { $s Z sR 8Z st R {s}$ st sIsR }B j $tR$ t pBI9$jjs et 8Z{YBR I R BR hj8 R js -}BR${$? Bt s{{$I t sj s js sI$s{$? Bt {BtR $ Zk ZtB I jBR 8 {sT t$R8BR } I$j { BR }s s j I Rs BjjB stB 8sj I jBR R R %$%BR JZ { { t I R8 RZ sIs8 t ZjB dD 7 s s t B{sR$Bt R I { $s Z sR R I PB 8st B R{s8 t B t{B t R$t ht w]s}? JZ AZR{st % t s R I js s9s YZ8sts JZ Ys sj sIB j B I t ts Z sj Os p B R ? j$r R st ${$}sAs js sI${$? Bt I jsR
8BtR 8B%$ R
{Bt
=t ABt j$
>dM H IBtI 8BR sAs $tR { BR
s $ st sIBR }B js s{{$? Bt I jBR skBR I js NZts _B{B I R}Z? R B B hj8
V F R k 7,
>d ((H ts sAs j tP t s8$ t B t Zt st` B k Zt 8BtZ8 t sj 8BRJZ$ B
Ns %$Is 8 I$s I j B BTd R I st R? BjB n n I? sR
© Los autores, 2001; © Edicions UPC, 2001.
x N k tIsR I Zt }jst s jjs8sIB q$ s
1nx
Ns {$t 8s B sP? s I jBR sK tBR x( % IsI s ? }B{s IB sIs I jsR } BIZ{{$Bt R I {$ t{$s h{{$? Bt } BIZ{ `BksR I j ? t B {B8B ej 8BtR ZB I $ 8}BR 8B BR >qY sR P B8 1( ((( 3s YT B8R d xnH %s s8 t $tR}$ sIs t j js B I isk sIAZ k Ns R$ ts t js t$ Ajs >qY 3B <B t d xdH IBtI Zt I$tBRsZ $B I R} sIB }B Zts -}jBR$? Bt tZ{j s sAstIBts RZ j s B k 8} tI j {s8$tB I %Z j s s {sRs Z$sIB }B RZ $tR $t BU {Bt tB`B I R{ZA JZ RZ %$ `B YB s R Ys {Bt% $IB t js s{ Zsj WZ %s OB , ! B hj8 I jBR {$t{Z t s y ]s8 P B8 T t s Y Y 7 s >d xxH 8Z R s jBR I R8st R I Zt }Zj}B {BjBRsjM PZ t I B BR RZA} BIZ{ BR {B8B Y 8B Y Y 7 s BtR >d x H B pB B >d EdH eR stIs I jsR 8BtR 8B%$ R I jBR x( Ns YZ8st$IsI t } j$ B >qY 8 d x;H ts s js } t $ts s}s ${$? Bt I $ st R{sR YB 8$ sR t j I R$ B RZj sIB I jsR } Z AsR tZ{j s R -${BD qs8A$? t jsR s sK tsR I gqs ? st Zjs sj$9sIsR sK tBR st R t Vjs8B B IB wWZ %B ? >qs st Zjs d xxH k qY 7}$I >d xMH js I R{B8Ztsj 8st $R j$ $BRs I qY * sIjk st $R >d x H B j R{B }$? Bt I qY js{, 7{B }$Bt >d x H RBt j RZj sIB I js $t` t{$s YZ8sts t j 8ZtIB st$8sj k 8Z R st js s $IZj{ Y t{$s I jBR I R8st R s ? B8${BR <B8A R {BjBRsj R {B8B j } B s Bt$R s I ej $ st s s{s >qY V8s9$t ]BjBRRsj st d x H k I RZ js8 t sAj R {Z js Gs BP Y ]BjBRRsj sR >d xMH Z B BR JZ }B s{{$I t R $t tst t Zt Zt$% RB RZA8${ BR{? B}${B {B8B ej $t{ ? Aj YB8A 8 t Zst >qY yt{ I$Aj 7Y $t,$t st d x H hj8 AsRsIB t j js B YB8? Bt$8B I i${Ys I s Y RBt B js {B8 I$s Ns $t{ ? Aj 8Z` 8 t Zst >qY yt{ I$Aj 7Y $t,$t GB8st d MdH RBt ` 8}jBR I R R YZ8stBR JZ -} $8 t st jBR P { BR I$s8 sj8 t B}Z R BR I js -}BR${$? Bt s js sI$s{$? Bt ]Bt pBI9$jjs R $t${$s Zts sI${$? Bt I 8BtR ZBR $ st R{BR ? }${s8 t "sthA$BR 8s{YBR k I sj$ t B j sj" wPZ B t pBI9$jjs Y$ jB t s s Bt k 4Z$IBR %s $BR t pY$IB sY k psBRD {Bt -{ }{$? Bt I B Y s Zts }Bj$jjs $ st qs8A$? t 8Z{YBR I jBR RZ} Y? B R I js I$ B $sj s % j Yst I Rs BjjsIB RZR }BI R I 8Z st R s{$sR s jBR IZIBRBR A t h{$BR I js sI$s{$? Bt w]s}? ZjB nD ej YB8A JZ %BjZ{$Bt? B >qY st bYB e%Bj% I d ndH I eI8BtI <s8$j Bt B 7 IR BP N$P >d ndH I FBYt qs$t ts st s8A$? t js stRPB 8s{$? Bt I YB8A R $ sI$sIBR t RZ} YB8A R 8 ? sPB sR I {? B8B js s tZ{j s Ys sj sIB js } R} { $%s YZ8sts
eP { BR A$Bj? B ${BR I js sI$s{$? Bt Ns sI$s{ $%$IsI ts Z sj PZ I R{ZA$ s I PB 8s PB Z$ s }B j P? R${B P st{? R Vt B$t < tB dM E IZ st ZtBR -} $8 t BR {Bt Rsj R I Z st$B Ns sT {JZ j wdMx1Td (MD t j sK I$s{$? Bt 8$ $Is }B j Z st$B PZ RZh{$ t 8 t $t tRs {B8B }s s s s% Rs I$% RsR {s}sR I }s} j Z RB $8} R$Bts Zts }js{s PB B ? sh{s {BjB{sIs t j B B - 8B 7? BjB ZtBR { t ts R I jBR 8$j R I t? Z{j BR {BtB{$IBR RBt R sAj R NBR t? Z{j BR $t R sAj R B sI$s{T $%BR -} $8 t st Zts stRPB 8s{$? Bt R}Bt ? st s t B BR t? Z{j BR JZ B $ $ts Zts {sI ts I I R$t s{$Bt R B{sR$Btsj8 t $t Z8}$Is }B js t s{$? Bt I Zt t? Z{j B R sAj NsR sI$s{$Bt R R {jsR$h{st t PZt{$? Bt I j sIB I } t s{$? Bt t js 8s $s et B I t { {$ t Z{j BR I Y j$BD jsR }s ? {ZjsR # w j { Bt RD jBR skBR wPB Bt R t 8BR jsR }s ? {ZjsR wt? I sj s t ? sD k jBR t Z Bt R NBR `$IBR %$%BR R ? st {BtR $ Z$IBR }B j 8 t BR I t? Z8 B s ? B8${B As`B w] < ! D k jsR $t s{{$Bt R JZ } R t st {Bt jsR sI$s{$Bt R $Bt$9st R {BtT 7 I${ JZ j t$sj R} {$sj$R s I P { BR R} {$sj R isk <s kYsZR t R? BjB }ZIB $8} B%$Rs Zt }Zj}B I R $R t ? s{ZjBR sj {s { I } RZ}Z R B M
© Los autores, 2001; © Edicions UPC, 2001.
1nE
*Â&#x201A; Â&#x20AC;$t Â&#x20AC;Bt s e$tR Â&#x201A;$t
3$ x x y8}Â&#x201E;BAsAjÂ&#x201A;R Â&#x201A;PÂ&#x201A;{ BR IÂ&#x201A; js Â&#x201A;-}BR${$? Bt s js Â&#x201E;sI$s{$? BtU Zt sRB8AÂ&#x201E;BRB {BÂ&#x201E;BtÂ&#x201A;j stt$t IÂ&#x201A; dx 8 IÂ&#x201A; sj ZÂ&#x201E;s ]sÂ&#x201E; Â&#x201A;j }ZAj${$ sÂ&#x201E;$B IÂ&#x201A; js }Â&#x201A;j? {Zjs ej $ st Â&#x201A; s s{s >qYÂ&#x201A; V8s9$t ]BjBRRsj st d x H
Š Los autores, 2001; Š Edicions UPC, 2001.
x N k tIsR I Zt }jst s jjs8sIB q$ s
1n
R$R t R t{$sj8 t t {Bj$R$Bt R {Bt j { Bt R NsR 8Bj? {ZjsR s jsR JZ } t { t JZ Ist sR? $Bt$9sIsR -{$ sIsR B sIJZ$ t Zt RZ}j 8 t B I t ? s ? 8${s {$ {ZtR st{$s JZ } BIZ{ P { BR tB{$%BR RBA jsR {? jZjsR JZ $t st * Y {YB tB -$R Zts js{$? Bt } B}B {$Btsj s t `Z BD k RZ P { B A$Bj? B ${B t j t? Z8 B I $Bt$9s{$Bt R k -{$ s{$Bt R wB js t ? {B R}BtI$ t Ns IBR$R 8? s-$8s } 8$ $Is I sI$s{$? Bt R Ys R sAj {$IB t (, x 8 }B sK tB ej %sjB 8 I$B s{ } sIB }s s j jBAsj I js }BAjs{$? Bt R Ys h`sIB t dbn( I R %sjB R I {$ ZtBR d ( 8$j$ 8 *sIB JZ {ZsjJZ$ -}BR${$? Bt s js sI$s{$? Bt {B8}B s Zt {$ B $ R B R BR %sjB R } R t st Zt {B8} B8$RB t jBR A t h{$BR I jsR sI$s{$Bt R w skBR I ZRB 8? I${B s}$s I j {? st{ { t sj R tZ{j s R D k jBR } j$ BR JZ ? R sR {B8}B st ]$ BR R ZI$BR 8? I${BR RZ $ t JZ js R} st9s I %$Is R IZ{ t d k d( sK tBR }B {sIs 8 {$A$IB t Zts RBjs -}BR${$? Bt
e-}BR${$? Bt w 8D d d( d((
eP { BR ]s8A$BR tB I { sAj R t j B st$R8B N$ BR {s8A$BR t js Rst ]s8A$BR 8BI sIBR t js Rst t? sZR sR j % R sj ? Zt IsK tB t js 8? IZjs B ?R s w R} st9s I {Z} s{$? Bt {B8}j sD
1(( ;(( E((
z? B8$ BR Ps $ s 8? sR {s8A$BR RZR st{$sj R t js Rst w R} st9s I {Z} s{$? Bt {B8}j sD eP { BR st $B R 8? sR $tP {{$Bt R Y 8B s $sR k R $j$IsI 8}B sj w w *sK tBR t j R$R 8s t %$BRB { t sj
M((
x(0 I 8Z R t E( I? sRD
x3(((
Z ? s}$Is s {sZRs I jBR IsK tBR t j R$R 8s t %$BRB { t sj
M(0 d((0 I 8Z R t E( I? sRD
qsAjs x d Vj ZtBR P { BR hR$Bj? B ${BR I js -}BR${$? Bt s js sI$s{$? Bt eR t{$sj8 t jBR P { BR } BIZ{$IBR }B js sI$s{$? Bt RBt {sZRsIBR }B U
T T
sj s{$Bt R I j PZt{$Bts8$ t B { jZjs I jBR `$IBR %$%BRU
Bt I j {${jB { jZjs js {s}s{$IsI I } Bj$P s{$? BtD k 8BI$h{s{$?
8Z { jZjs w}? I$Is I
P { BR t? ${BRU 8Z s{$Bt R NsR 8Z s{$Bt R RBt j R$Bt R I j 8s $sj t? ${B j *WV }B{B B 8sj }s sIsR _ R sj }s} j I R 8} K tsIB }B jsR 8Z s{$Bt R t js %BjZ{$? Bt I jBR B st$R8BR %$%BR js 8skB ? s I jjsR RBt } `ZI${$sj R
<Bk t I? s tB R sZ B $9s JZ t$t ? Zt I$R}BR$ $%B B s{ $%$IsI JZ t sI$s{$Bt R RBA }sR js IBR$R 8? s-$8s } 8$ $Is I sI$s{$? Bt VZtJZ I {ZsjJZ$ PB 8s jBR R R %$%BR R$ 8} Yst R sIB -}Z R BR s js sI$s{$? Bt ts Z sj } BIZ{$Is }B jBR skBR {? BR8${BR k }B 8s $sj R sI$s{ $%BR } R t R t js ts Z sj 9s 7 R $8s t MM 8$j$ 8 js IBR$R stZsj sARB A$Is }B I${YB 8B $%B NBR skBR {BtR $ Zk t js PZ t s $h{$sj 8? sR $8}B st I -}BR${$? Bt s js sI$s{$? Bt et Zts RBjs sI$B sP? s I ZtBR }B{BR R ZtIBR I IZ s{$? Bt }Z I {$A$ R Zts IBR$R I 1(( 8$j$ 8
© Los autores, 2001; © Edicions UPC, 2001.
1nM
* $t Bt s e$tR $t
3$ x E yt{ ? Aj R ZRBR I jBR skBR R ? Zt p B R ? j$r R t } B8 I$B _B jjB sj ZtBR {$ t ? h{BR {js8st }B Zts IZ{{$? Bt I j ZRB uk sAZRBu I jBR skBR t jBR I$s t? BR ${BR 8? I${BR et dM }B{B I R}Z? R I RZ I R{ZA $8$ t B j * FBYt {yt k } R t sAs Zt hj8 t j JZ R 8BR sAst sI$B sP? sR I j RJZ j B I Zts sts et B{ ZA I j 8$R8B sK tB s}s {? s Zts } j? {Zjs {? B8${s RBA j ZRB I jBR skBR qY Tisk 3$ tI >dM H k 8 R R I R}Z? R N R iskBtR iB t t >dM H I j $t{B8AZR $Aj ? j$r R IBtI j RJZ j B I Zt YB8A %$RZsj$9sIB 8 I$st Zt JZ$}B I skBR g R{s}s I j {Z }B I RZ IZ K tB =t ` 8}jB I I$R}BR$ $%B JZ Z $j$9s j }BI I } t s{$? Bt I js sI$s{$? Bt t js 8s $s }s s I R{ZA $ BA` BR ws 8sR t R {sRBD jB t{Bt s8BR t j hj8 * RsP? B B sj >qB sj i {sjj d (H AsRsIB t j js B I _Y$j$} *${, =R I jB {B Is ? s } P { s8 t >G ]st i 8 8A y PB OBZ GYBj Rsj d EEH Ns } j? {Zjs ts s jBR - sK tBR RZ K tBR JZ s B 8 t st s *BZ +Zs$I t js q$ s I j sK tB 1(M; RZ K tBR JZ j Ys{ t IZIs I RZ % IsI s $I t $IsI 7$ Z$ tIB Zt {js8B }ZAj${$ s $B +Zs$I %$R$ s i ,sjj yt{ Zts s t{$s R} {$sj$9sIs t $8T }jst s {Z IBR k R tRs{$Bt R JZ Ys{ t %$%$ js h{{$? Bt {B8B R$ PZ R sj et Rs ? }B{s jBR ZRZs $BR I j 8 B }sRst s s%? R I }st sjjsR I { B sR I s 8sRU R s s I Zts R} {$ I I$R}BR$ $%B I skBR {B8B jBR Z $j$9sIBR t jBR {Bt Bj R I jBR s B}Z BR B }s s I$s tBR$R 8? I${s ks JZ RBA js }st sjjs R %$RZsj$9st R? BjB jBR RJZ j BR k jBR BA` BR 8 ? sj${BR NBR YZ RBR k jBR 8 sj R } R t st Zts 8skB B}BR${$? Bt sj }sRB I js sI$s{$? Bt $8} R$BtstIB t 8 tB sIB js }js{s B }st sjjs IBtI R {B js sI$s{$? Bt JZ jsR B sR }s R I j {Z }B {BtR $ Z$IsR }B sRs 8? ZR{ZjBR { VR? }B R$8}j {Bt sR jsR s 8sR RZj st P? s{$j8 t I { sAj R Ns {Bt s}s $Is tB BAR st R 8Zk j %sIsU {sIs % 9 JZ Zt YsA$ st I R s 8 sj? B}Bj$R PZ Z s JZ 8Z R s j hj8 }sRs P t sj I { B {$A Zts IBR$R I sI$s{$? Bt s R $8sIs t ZtBR 1(( 8$j$ 8 7$ }s s $ s sAs`s wsj B JZ } RZ8$Aj 8 t R I A ? st B I$s $s8 t k RB8 T {Bt $tZs Ys{$ tIB t j PZ Z BD Ysk JZ {B j stR}B RZA ? R sj I { B I skBR 5JZ? IBR$R YsA ? s s{Z8ZjsIB Zt B st$R8B %$%B sj {sAB I Zt
© Los autores, 2001; © Edicions UPC, 2001.
x N k tIsR I Zt }jst s jjs8sIB q$ s
1n
sK tB2 7Z}Bt$ tIB 1 %$s` R I$s $BR w$Is k %Z j sD k ZtBR 1x( I? sR jsAB sAj R sj sK tB RZj st gd(( 8 7 R $8s JZ {Bt Zts IBR$R stZsj I d(( s x(( 8 R IZ}j${s js } BAsA$j$IsI I 8B $ I {? st{ k JZ I 1x s dx( 8 R IZ}j${s js } BAsA$j$IsI I -} $8 t s 8Z s{$Bt R =t sR} { B JZ jBR R}BtRsAj R I jBR stR}B R }? ZAj${BR I A ? st t A$ t } R t t j PZ Z B _ pBBI{Y$jI t RZ $t Rst A$B sP? s RBA js h Z s I j P? R${B F iBA !}T s ${B s{{$I t RZP $IB }B <s k *s Yj$st j 1d I s BR B } tY $8 wd (;Td E D ts s j ? I d ;x $ t sR sj$9sAs -} $8 t BR {Bt P s 8 t BR I Z st$B *s Yj$st Zt `B% t P? R${B JZ sAs`sAs s jsR B ? I t R I ! B 3 $R{Y t NBR Vjs8BR RAsj? B }Bt$ tIB t {Bt s{ B Zts {st $IsI { ? ${s I Z st$B Ns PZ s9 k 8 s $s s{ Zs{$? Bt I j } B}$B *s Yj$st $ stIB }s I j Z st$B %$ ? B Zts I R{B8Ztsj {s ? sR BP } B js IBR$R j sj I sI$s{$? Bt {$A$Is s{sA? B {Bt RZ %$Is t R? BjB 1M I? sR
$ s $B Os t d 1 j A$Bj? B B < F Zjj $tIZ{? s 8Z s{$Bt R t 8BR{sR }B $ sI$s{$? Bt -} $8 t B JZ {sZ $%? B j } tRs8$ t B k js $8s $ts{$? Bt }B}Zjs =tB I jBR } $8 BR sZT B R t { $R sj$9s {Bt{ } BR st Pst ? sR ${BR t Zts tB% js I h{{$? Bt PZ FBYt qs$t JZ$ t t >d 1 H ts s jBR -} $8 t BR t? ${BR s JZ RBt RB8 $IBR R tIBR {sI? s% R I RsZ $BR $ st R 8 $IBR I jsR } BPZtI$IsI R et B s I RZR BA sR ? >d n(H js {s? Is I Zt 8 B $ B stRPB 8s Zts $? Bt I VP ${s t Zts `Zt js I -? B ${sR 8 s8B PBR$R Vj ZtsR 8Z s{$Bt R Yst R$IB $t%B{sIsR {B8B PZ t R t { Rs $sR }s s j } BT RB {B8B t >=t$% R d ;dH I iBA V < $tj $t B t >3BZtIs $Bt stI e8}$ d x1H I yRss{ VR$8B% JZ ts s js s}s ${$? Bt I Zt j? }s s tB } I${YB }B js }R${BY$R B $s ? sR {$ t 8 t V V V stsR$B I R{ $A t >d MdH jsR sj s{$Bt R } BIZ{$IsR t tZ R B }jst s sR js I R Z{{$? Bt I jBR R{ZIBR 8s t? ${BR R R }B }s I Zts $t tRs sI$s{$? Bt $t{ 8 t sIs }B P { B I Zt s Z` B t B { {stB NsR 8Z s{$Bt R } BIZ{$IsR RZj st $Aj R
8Z s{$? Bt PZ }B}Zjs $9sIB }B j AB ? st${B YBjstI? R <Z B I z $ R wdM;MTd nxD t RZ BA s *$ Z s $BtR Y B $ >d (dT(nH IBtI R js{$BtsAs {Bt stI R sj s{$Bt R I {s ? s{ Y IT qY p s R VI% t Z =t$% RB
Ns -}BR${$? Bt s js sI$s{$? Bt }Z I P { $%s8 t $tIZ{$ 8Z s{$? Bt { jZjs ej {Bt{ } B I
7 s
qY y Bt
3ZtIs{$? Bt y8} $B j 8ZjB isI$-
ej $ st $R8B 8BR sIB t jBR hj8 R I jBR sK tBR x( {B8B jsR YB 8$ sR I BA I { s Zts I R sR 8Z s{$Bt R {Zks {sZRs R js{$Bts {Bt js -}jBR$? Bt tZ % sK tBR st R I js } $8 s AB8As s ? B8${s t j I R$ B I GY$ 7stIR t WZ %B ? -${B WB BAR st I${YB P { B RBA j { {$8$ t B }s { -s sIBU j $ st $R8B tB jj s tZt{s s } B%B{s js s}s ${$? Bt I $tI$%$IZBR 8? sR sj BR JZ j IBAj I js sjjs tB 8sj ]B8B R {B8 t ? B t j {s}? ZjB d j YB8A 8? sR sj B I j JZ R $ t tB ${$s 8 I? s ZtBR 1, ( 8 sj I IB I d, x % { R js sj Z s 8 I$s I js R} {$ YZ8sts NsR YB 8$ sR I sj{st9st Zt s8sK tB d3((( % { R 8skB JZ j YsA$ Zsj NsR {? jZjsR JZ R ? st t } B{ RB I s { {$8$ t B RBt sj s8 t R tR$Aj R s js sI$s{$? Bt w{$ {ZtR st{$s JZ R s} B% {Ys YBk t I? t js jZ{Ys {Bt s j {? st{ D eR B RZ $ JZ I R}Z? R I js -}jBR$? Bt I js } $8 s AB8As s ? B8${s sj ZtsR js %sR I YB 8$ s I A? st YsA R$IB $ sI$sIsR _s { {Z R $BtsAj }B JZ? 8Z s{$Bt R } BIZ{$IsR tZ % sK tBR st R Yst s IsIB st B t 8s $sj$9s R =ts YB 8$ s $ts }Z I I }BR$ s I { tsR I 8$j R I YZ %BR t Zt 8 R k jsR YB 8$ sR BA sR JZ RZ t I R BR YZ %BR %$% t ZtBR {Zst BR sK tBR VR? BIB j I R$ B I WZ %B ? -${B I A ? s R s }j B I YB 8$ sR $ st R AZR{stIB sj$8 t B ej * IPB I {$ t ? h{B I Z tB -} B t
} j$ B
Ns YZ8st$IsI t
Ns YZ8st$IsI t } j$ B
© Los autores, 2001; © Edicions UPC, 2001.
1;(
* $t Bt s e$tR $t
$tR { BR s Z8 t s JZ js {sZRs I js 8Z s{$? Bt Ys R$IB Zts -}BR${$? Bt {Bt $tZsIs k } R$R t s js sI$s{$? Bt et R {sRB I A ? st % R sP { sIBR B BR B st$R8BR sI 8? sR I jsR YB 8$ sR et RZ8 t j }jst s8$ t B JZ RAB9s j hj8 RBA js s}s ${$? Bt I YB 8$ sR 8Z st R tB }s { I 8sR$sIB s{ sIB YsA$Is {Z t s sI 8? sR I js sj s{$? Bt I RZR Y? sA$ BR sj$8 t ${$BR k I RZ tB%sIs sh{$? Bt }B $t $ $tPB ZtsIBR w5k RsA BRBR2D YZ8stBR
ej P ? B k jsR $t$ AjsR I Zts ts%$IsI Ajst{s wtZ{j s D FZt B s jBR P { BR j$8$ sIBR I js -}jBR$? Bt I Zts AB8As s ? B8${s wsj s{$? Bt { jZjs P { BR t? ${BR D R Yst $t% R $ sIB {$ t 8 t B BR P { BR s R{sjs jBAsj I Rs BjjB I js AB8As I PZR$? Bt 8BtZ{j s js Os IZ st j
RZ}
{B8B R js {BtB{? s {BjBJZ$sj8 t
sj ZtBR {$ t ? h{BR YsA? st s}Zt sIB j 8B s JZ js j$A s{$? Bt I Zts $t t {st $IsI I t ? s 8$ts s }B g t{ tI js } B}$s s 8? BRP s R et `Zj$B I d ;1 8$ t sR
} BR Z? st jBR sAs`BR JZ {Zj8$ts Bt t js PsA ${s{$? Bt I js } $8 s AB8As s ? B8${s I hR$? Bt R YsA? s 8} 9sIB s R} {Zjs {Bt j I Rs BjjB I Zts AB8As I PZR$? Bt {Zks PZ t I t ? s
$8$ sR
j $t $B I jsR R jjsR ej P? R${B I B $ t Y? Zt s B eIbs I q jj
}sI
I js AB8As
I PZR$? Bt jj ? B s }jst s s !}} tY $8 JZ js t ? s j$A sIs t js PZR$? Bt I t? Z{j BR I I Z $B }BI? s jj s s t s Zts 8} s Z s RZh{$ t {B8B }s s $t${$s js s{{$? Bt t I Z $B k t$ ? B tB ej t$ ? B tB R j {B8}Bt t PZtIs8 t sj I js s 8? BRP s R _ R s JZ R
_B {BtR$ Z$ t js } B}$s s 8? BRP s }BI? s t{ tI R sj I Bts js AB8As
sj$9s Bt {$ t BR I {? sj{ZjBR }s s stsj$9s uk I R{s s u I${Ys Y$}? B R$R js }s stB$s RBA js $ t${$? Bt I js s 8? BRP s R } 8st {$? B YsR s j I? s t JZ R jst9? B js } $8 s AB8As I Y$I ? B tB
3$j8 R {B8B
Ns Z s I jsR sjs-$sR
>7 s Gs R d H Yst {s}$ sj$9sIB j }? st${B RZR{$ sIB
}B Zts {BtP Bt s{$? Bt s ? B8${s {Bt js I R Z{{$? Bt I }jst sR t BR {B8B VjI sst 5_BI ? s jj s R s I R Z$ js } B}$s q$ s IZ st Zts Z s tZ{j s 2 Zts R$8}j AB8As * Y {YB js I Bts{$? Bt I
sjPsTB8 s >
R s js -$R t{$s I tZ R B } JZ K tB 8ZtIB s9Zj t
i RB sj
}jst s I jBR R$8$BR
t s Y Y _jst BP Y V} R d E H ! B }jst s R$8$js s js q$ s
Vj s$ yz R IZ{$IB s sK t${BR sR js } $t t -}jBR$? Bt I jBR 1(( s{ B R tZ{j s R $ $IBR }B js - $t s s9s
, jj
t
_jst s } BY$A$IB t ? s I j$ sIZ s
_s s I R Z$ Zt }jst s R t { Rs $B
j$A s Zts t ? s JZ$%sj t B RZ} $B s js t ? s I B $ t s%$ s B $B 8}j sIs t js PB 8s{$? Bt I j R$R 8sU js jjs8sIs _ R s JZ js I tR$IsI R tB
R Zt$PB 8 t j $t $B I js q$ s }Z I Ys{ R Zts } $8 s R $8s{$? Bt I js t ? s I j$ sIZ s I j }jst sU
o
) ;
d(
n1
F Ns -}jBR$? Bt I BIB j s R tsj tZ{j s R R $8sIB
t ZtBR dx ((( 8 s Bt R j$A s ? s Zts t ? s I ZtBR d( I R Z$ js
d
q$ s
F {js s8 t $tRZh{$ t }s s
VR? hj8 R {B8B
Vj$ tR j RB
>Vj$ tR d MEH IBtI js -}jBR$? Bt I j
s{ B tZ{j s I js R s{$? Bt I } B{ Rs8$ t B s 8BRP? ${B t j t$% j N z ;1E j$A s ;( 8 s Bt R I t ? s 8Z R st P { BR 8? sR s{B I R {Bt js sj$IsIU js I Bts{$? Bt sP { s Zts $? Bt I n( ,8 I sI$B k I R Zk jsR $tR sjs{$Bt R } B tB j }jst s NBR } JZ K tBR Rs ? j$ R 8s {$stBR 3BABR k * $8BR } R t st t ? sR I j$ sIZ s } JZ K tsR t {B8}s s{$? Bt {Bt jsR I jBR }jst sR I j 7$R 8s 7Bjs ZtBR x
d(
d F
k ;
d(
dE F
R} { $%s8 t `ZR B t j Z8A sj
_s s js I$R Z}{$? Bt {B8}j s I js q$ s R JZ $ ? st ZtsR x d(dM AB8AsR s ? B8${sR {B8B js jst9sIs RBA <$ BRY$8s t s BR B I d ;x
© Los autores, 2001; © Edicions UPC, 2001.
x N k tIsR I Zt }jst s jjs8sIB q$ s
1;d
I j }BI I R Z{ $%B I B $ t tZ{j s I js YZ8st$IsI _B {BtR$ Z$ t js I R Z{{$? Bt I } JZ K tBR sR B$I R {B8B jBR JZ s}s { t t ej y8} $B {Bt ss s{s >qY e8}$ 7 $, R s{, d M(H 8 I$st $8}s{ BR I$ { BR RZh{$ t 8 t t ? ${BR }s { AsR st s9BtsAj t ? 8$tBR t ? ${BR WB R -s sIB s% t Z s jBR $ R BR I Zts {Bt4s s{$? Bt tZ{j s et <$ BRY$8s js -}jBR$? Bt B js 8Z I ZtsR d(( ((( } RBtsR 7 R $8s I Zt s Ps{ B I R? BjB d1 ,$jB Bt R@ {sZR? JZ t Zt $t {s8A$B I x ((( 8 s Bt R 8B $ ? st ZtBR d ((( 8$jjBt R I } RBtsR }B js Bjs I {sjB t sIs k B BR d ((( 8$jjBt R 8? sR }B P { B I jsR sI$s{$Bt R VR? et jBR js $IBR I js tB{Y > b t Y 7 B, R BP Y W$ Y d MxH I ]Ys j R 7Y ^ jI ts s Zts {BtP Bt s{$? Bt tZ{j s B sj JZ s9B s js q$ sU js RZ} h{$ I tZ R B 8ZtIB R s sRsIs IZ st j {Bt4${ B t j JZ R j$A st } {$Rs8 t n( ((( 8 s Bt R ZtsR x Bt jsIsR I qWq }B YsA$ st _B {B8}s s{$? Bt j s Ps{ B 8? sR }B t I BtsIB t js q$ s Ys R$IB Zt $t t$B RB%$? ${B I xM 8 s Bt R JZ j n( I B{ ZA I d Ed -}jB ? B t WB%sks 8jks <Bk t I? s Zts Z s tZ{j s B sj R {Bt 8}js As`B j Pst sR8s I j I tB8$tsIB $t%$ tB tBR tZ{j s k j ht I js %$Is t js q$ s *$% RBR R ZI$BR@@ sj$9sIBR s } $t{$}$BR I jBR sK M( I R sAst js {Bt` Z s I Zt sZ8 t B sIZsj I js 8} s Z s I j }jst s sR Zt {Bt4${ B tZ{j s sj }B t{$s R j P { B $t% tsI B {Bt js j$A s{$? Bt I sR R {B8B j I$? B-$IB I {s ABtB ej R ZI$B qqV_7 I 8BR sAs JZ 8Zk sj {Bt s $B 8 R R I { ZIB $t%$ tB tZ{j s R Z$ ? st s Zts {BtP Bt s{$? Bt tZ{j s jBAsj }B P { B I j sZ8 t B I js B}s{$IsI s 8BRP? ${s Ns k {{$? Bt I sR k }Bj%B IZ st js {Bt $ tIs } B}B {$Bts ? s Zt h{$ t R{ZIB JZ j$8$ s ? s j }sRB I sI$s{$? Bt RBjs } BIZ{$ tIB Zt tB sAj I R{ tRB I js 8} s Z s 3$j8 R {B8B +Z$t B >+Z$t d H 4 `st js { ZIs -$R t{$s t sj R {BtI${$Bt R I %$Is Z{YBR js BR Yst stsj$9sIB j I s8s I Zt YBjB{sZR B I RI j }Zt B I %$R s ts s $%B I js {BtR Z{{$? Bt I js RB{$ IsI I jBR %sjB R YZ8stBR k I js } B}$s %$Is t js q$ s 8? s ${s JZ s8A$? t Ys s s? IB s R{ $ B R %$t{ZjsIBR s js j$ s Z s t sj ej s Z8 t B RZ j s ${Zjs R I s{Z IB {Bt Zt s JZ $}BU Ist R{B YBjB{sZR B R Z$IB }B Zts wjs sD PsR I As As $ IBtI j 8skB B {BtR$R t R Z$ %$%B ej sR R$ts B RZ j R P {Z t _s sI$ 8s I j I RBjsIB R{ ts $B }BR tZ{j s jB {BtR $ Zk sI s- Rsj%s` R I js sZ B}$R s ? > sI s- d H hj8 t j JZ AstIsR s 8sIsR JZ { st js R ? ${s I jBR Vt j R I j $tT h tB {s8}st }B IBJZ$ I I${sIsR sj RsJZ B B{sR$Btsj Ns $t4Z t{$s I sI s- I `? B YZ jjs t j {$t I jBR M( {Bt 1 R {Z jsR {BtB{$IsR w sI s- 1U j Z B I js {s s > sI s- 1 d MdH k sI s-U 8? sR sjj? s I js {? Z}Zjs I j Z tB > sI s-U kBtI qYZtI IB8 d MxHD k Zts js s {B $ t I $8$ sIB R {B8B ]kAB >]kAB d M H 7j$}R s8 js PZ $s
=t ,$jB ? Bt {B R}BtI s d ((( Bt jsIsR I $t$ B BjZ tB qWq 7Z }BI -}jBR$%B JZ$%sj s ; d(@ F @@ WZ{j s G$t U pjBAsj ]BtR JZ t{ R BP Zj $}j WZ{j s e-}jBR$BtR I i${Ys I _ qZ {B !b t qBBt qYB8sR _ V{, 8st Fs8 R _Bjjs{, k ]s j 7s st {BtB{$IB t YBtB I RZR sZ B R {B8B R ZI$B qqV_7 *${YB $tPB 8 PZ P tIsIB }B Zts FZt s I VR RB s8$ t B ]$ t ? h{B {B8}Z R s }B R R t s k Zt $t% R $ sIB R wP? R${BR tZ{j s R BP? R${BR 8 B ? BjB BR k A$? BjB BRD I js {B8Zt$IsI {$ t ? h{s $t ts{$Btsj ej R ZtIB $tPB 8 R qY NBt Tq 8 $BjB ${sj ]BtR JZ t{ R BP WZ{j s Gs I _sZj i eY j${Y ]s j 7s st 7 }Y t F pBZjI k B BR @
© Los autores, 2001; © Edicions UPC, 2001.
1;1
* $t Bt s e$tR $t
3$ x e%BjZ{$? Bt w5YsR s {Z? stIB2D I js {tBjB ? s 8$j$ s t jsR RZ{ R$%sR Z sR 8ZtI$sj R I j %$ t B >7j$}R s8 d M H B <s Ibs } B s8sIB }s s 8s s ><s Ibs d (H ej hj8 * P{Bt ; >d M;H ts s j I RsPB ZtsIB B tB I Zts ts% R}s{$sj s Zts q$ s s sRsIs }B Zt YBjB{sZR B tZ{j s ej } B}$B {s}$ ? st I js ts% R R {Z R sIB k j$ sj8 t I %B sIB }B YB IsR I {st? Asj R st Rsjs I js As As $ 8 t I Zts RB{$ IsI } $8$ $%s <B B JZ {Bt sR s {Bt j sRB8A B I j `B% t {s% t? {Bjs I
q ts ]s% 8st >d xMH
sj I R{ZA $ JZ RZ
8ZtIB tB R js {Zts I Zts {$%$j$9s{$? Bt R$tB js R? B I$Is Y t{$s I Zts RB{$ IsI {t$h{sIs I %sR sIs }B Zt YBjB{sZR B
q sR js PsR I As As $ j {Z RB %BjZ $%B I jsR RB{$ IsI R I j }BR YBjB{sZR B RZ j } BR Z$ {Bt js $tR sZ s{$? Bt I Zts R Z{ Z s 8s {sIs8 t P ZIsj AsRsIs t 8BI jBR RB{$sj R I js IsI 8 I$s t Vt ${$}? stIBR sj 8st$IB {j${Y? }BR YBjB{sZR B i${Ys I F & $ R I R{ $A? s >dMMxH j js}RB t j As As $R8B $tR sZ sIB sR Zt YBjB{sZR B 8ZtI$sj
VP NBtIBt
k j sI% t$8$ t B I Zts RB{$ IsI I R ? ${s 8 I$ %sj d nEH AsRsIs t js tB% js I < p G jjR jsR {s s{ ? R ${sR st $Z B}? sR I RZ sZ B
Ns %$Is PZ Z s >qY$t R B ]B8 qY 7Ys} BP qY$t R B ]B8 R B B ` 8}jB I q sR js I %sR sIB s Z s JZ s sRs js s}s{$Aj
e% k Bbt js RB{$ IsI %BjZ{$Bts Ys{$s Zts R Z{ Z s P ZIsj BA tsIs }B Zt I R}? B ${B j? I qs8A$? t Vt js ]s t RZ tB% js
<? B R k %$jjstBR >< B R stI z$jjs$tR d E H 8Z R s Zts =t t$K tB k RZ } B
yt js s }BR tZ{j s t js JZ js RB{$ IsI R Ys R{$tI$IB t js ? $Is ? j$ I } BP RB R wk s As BR I jBR ABRJZ R 8Z sIBR js {B R}BtI$ t R{Bj s I RBjIsIBR JZ jBR Zs IstD k jBR A? !A s 8s R s I j ? t B R j t$sj >V Bk stI <$R *B d E H I <s jst
ejj$RBt hj8sIB YB8? Bt$8s8 t t d x
ej js B I R{ $A js 8}s ? s I Zt t$K tB k RZ {st
JZ sR Zt YBjB{sZR B tZ{j s Ys I Rs BjjsIB }BI R j }? s ${BR ej 8B ABRB {Bt s{ B {Bt js ? $Is RB{$ IsI JZ YsA$ s jBR 8ZtIBR RZA ? st BR sR st` s R js s8$R sI I Zts t$K ts htsj$9s {Bt ? R s {Bt% $Is t hj R k RZ j% s js }s Zt {B8}j${sIB $? st ZjB s8B BRB
V,$ s
>d MMH B B ` 8}jB I hj8 }BR YBjB{sZR B s8A$ t sIB t j qB,$B I j R$ jB y $jZR s js I {sI t{$s RB{$sj s js JZ js YZ8st$IsI R % sAB{sIs sR js s I$s
© Los autores, 2001; © Edicions UPC, 2001.
x N k tIsR I Zt }jst s jjs8sIB q$ s
1;n
ej tZ %B 8ZtIB RZ j % R t 8skB s 8Bt? s {Bt js ts Z sj 9s B8stIB js R tIs I Zts {sR$ Z B}? s ! sR tB% jsR tB BAR st PZ 9st js jZ{Ys 8B{$Btsj t jB stsIB k jB } I$IB t Zt tZ %B Y? sA$ s {ZksR }B t{$sj$IsI R tB t { Rs $s8 t {B8} tRst js Bj%$IsIs {BtPB T sA$j$IsI I j }sRsIB V Z8 t B 8s {sIs8 t 4 -$%B $t BR} { $%B R j I 3$% >d xdH IBtI {$t{B YZ8stBR I I$% Rs {BtI${$? Bt wZts 8Z` 8As s9sIs Zt YB8A I {BjB Zt $I sj$R s Zt sR R$tB k Zt YB8A s Bt$9st D -}Bt t RZR 8B $%BR }s s R Z$ %$%$ tIB t Zt 8ZtIB I %sR sIB q R k tB {$t{B RBt jBR RZ} %$%$ t R I j YBjB{sZR B I qY GB jI Y 3j RY stI Y * %$j >d xMH AsRsIs t Ns tZA }? Z }Z s >qY _Z }j ]jBZI d (dH I _ 7Y$ j ej tP t s8$ t B t jBR IBR YB8A R }B js Z ?t${s 8Z` RZ} %$%$ t 8$ts {Bt Zt htsj RB } Rs }s s js ? }B{sU Zt $t R} sIB $? st ZjB s8B BRB qY NsR GB8st Bt es Y >d E(H }s I js 8$R8s } 8$Rs JZ js st $B {Bt Zts 8Z` RZ} %$%$ t sR Zts j$8$ sIs $t -}j${sIs Psj s I B-? tB t js s 8? BRP s R qs8A$? t Ns YB s htsj >d x H I R{ $A j $Aj I s8s YZ8stB I Zts {s ? sR BP tZ{j s 7? BjB VZR sj$s R Ys j$A sIB I js {s? Is I jBR $t t$BR tZ{j s R } B RZR YsA$ st R s Zs Ist {Bt RZ8$Rs $8}B t{$s js jj sIs I js tZA j sj I sI$s{$? Bt ej $t 8$tsAj {B $IB }B YBjB{sZR BR k 8ZtIBR }BR tZ{j s R tBR jj %s s Zts Z ?j $8s }s sIsU jsR tB% jsR IBtI js {$ t{$s $t{Zj}sIs }B j B{sRB I js {$%$j$9s{$? Bt R {Bt%$ t Zts I$R{$T }j$ts } BR{ $ s k RZR I P tRB R RBt } R Z$IBR k s`ZR ${$sIBR e` 8}jBR {B8B s IB9 >d nH IBtI Zts 8$tB ? s I {$ t ? h{BR R s s{sIs }B A? s As BR B j {Z $BRB js B I qYB8sR ]sj% {]js k i A$ Y >d n;H t j JZ Zt {$ t ? h{B YsR $sIB }B j } B RB k js I {sI t{$s I js {$%$j$9s{$? Bt $t% t s Zt skB JZ $tIZ{ s Bj%$Is BIB {BtB{$8$ t B sIJZ$ $IB $t{jZ$IB j YsAjs Z{YBR R R YZ8stBR 8Z t t j $t t B 8$ t sR JZ Zts 8$tB ? s {BtR$ Z IZ{s R k sj{st9s j t$% j {tBj? B ${B t R? BjB d( sK tBR Ns t B8 I${$ts k B sR ? {t${sR sj ts $%sR JZ {B8A$tst {Z RBR A$B{$ t ? h{BR k 8 I${$ts ts Z sj } Bj$P st s8A$? t t j 8ZtIB }BR tZ{j s I 7 }$ t I j RZ K tB >* s8Rts, d MH I js R{ $ B s zBtIs W {yt k VZtJZ tB R$ 8T } js RB{$ IsI s} tI I RZR B R {B8B 8Z R s js tB% js I }BR YBjB{sZR B ]? st ${B }B N $ABb$ 9 >V ]st ${j PB N $ABb$ 9 d E(H I Gsj $jj % IsI s BA s 8s R s I j ? t B `Bks I js $ Bt? s j$ s $s IBtI Zts {Z $BRs j$ $? Bt RZ $Is I jsR { t$9sR I js {$%$j$9s{$? Bt $9s j $9B I j ? t B sIB stIB BA` BR I {Zj B JZ YsA? st } t {$IB sj 8$ 8A B PZtIsIB I js B I tU gZts %$ `s j$R s I js {B8} s k j I$R K tB I Zt {$ {Z$ B j { ? Bt${B x n qB tsIBR %Bj{st R k B sR {s ? sR BP R
* RI $ 8}BR $t8 8B $sj R js q$ s R Ys %$R B {Bt%ZjR$BtsIs }B 8? Zj $}j R I RsR R ts ZT sj R w 8B BR $tZtIs{$Bt R B tsIBR %Bj{st R }js sR D t B{sR$Bt R s $AZ$IBR s js $t` t{$s I$%$ts qs8A$? t js 8stB I j YB8A @ w Z sR R{s} R sI$s{ $%BR }BjZ{$? Bt s8T A$ t sj D Ys sj sIB j B I t ts Z sj 7$t 8As B j s JZ $}B I js I R Z{{$? Bt 8sR$%s {Bt{ A$IB }B js {$ t{$s h{{$? Bt js $t%sR$? Bt - s R R R$R s { Z9s j tZ Z8T A sj JZ R }s s sj$IsI k h{{$? Bt _B sYB s NsR tB% jsR I {s ? sR BP R Yst %$%$IB ? }B{sR eR stIs $ ? Bt${B I j RsA$B jB{B ]Zts I s B >]s :R ] sIIj d EnH I j t$sj Z zBtt Z I R{ $A js %$Is k js BA s I 3 j$- <B t$,, I R{ZA $IB I j Y$ jB Zts RZR st{$s JZ {Bt js BIB jB JZ B{s s8 ts9stIB js %$Is t js q$ s @
© Los autores, 2001; © Edicions UPC, 2001.
1;;
* $t Bt s e$tR $t
IB sIsR A? sR${s8 t $8}ZjRsIsR I RI j i $tB =t$IB {Bt js BR }s sI$ 8? s ${BR {B8B qY _Z }j ]jBZI >d (dH I s Y b _ 7Y$ j IBtI Zt sR j sj w? s{$IB {$stY? I ${BD 8stsIB IZ st Zts Z}{$? Bt %Bj{? st${s I R Zk BIB % R $ $B I %$Is -{ } B s Zt YB8A k s Zts Bt 8sR$%s AsRsIsR t 8Z` U Zt tZ %B VI? st Zts tZ %s e%s@n ! sR PB 8sR I I R Z{{$? s}B{sj? } ${sR $tZtIs{$Bt R t{Z t st RZ }Zt B s ?j $IB t tB% jsR }$Bt sR {B8B * jZ >d 1MH ZjB t d nnD IBtI Zts s} {$sAj }B {$? Bt I j I 7 3Bbj G $ Y whj8sIs {Bt j 8$R8B ? $ B $B A $ ? st${B JZ Is st sIs }B jsR s ZsR F p sjjs I I R{ $A Zt NBtI R $t -B sAj T 8 t $tZtIsIB sR j I {j$% I jBR {sRJZ R }Bjs R t ej 8ZtIB RZ8 $IB >qY * Bbt I GB jI d E1H 8Z R s I B B tB sAj ` {${$B j$ s $B ! s I RZR BA sR Ns R JZ? s >qY * BZ Y d E;H R I R}js9s sj B B - 8B I js - s}Bjs{$? Bt {Bt Zt 8ZtIB s ? $IB AsK tsIB }B Zt RBj sA sRsIB Ns IZsj$IsI "8ZtIB st sIB" % RZR "8ZtIB I R? ${B" }sRs s {Bt% T $ R t 8s {Z t I js j$ s Z s k {$t 8s B sP? s I j ? t B {B8}j stIB js $jB ? s 8? s ${s jBR 8ZtIBR IB8$tsIBR }B Zt tB $t%$ tB tZ{j s {B8B j hj8 +Z$t B B }B Zts tZ %s s js{$sj {B8B t qY GB jI $t G$t >d E1H I FBYt ]Y $R B}Y 7$t 8As B j {js8B A? Aj${B I j I$jZ%$B Zt$% Rsj }s { YsA I {st sIB js Asjst9s Ys{$s jBR js BR RBT A 8ZtIBR st sIBR VR? qY V$ s j U V z$R$Bt BP Y 3Z Z >dMx H I < 8stt Nst I R{ $A j B{sRB I js {$%$j$9s{$? Bt Z B} s I R Z$Is }B $ ? st${sR $tZtIs{$Bt R k R ? R8BR =ts {BtP I s{$? Bt tB sP ${sts R js t{s sIs I s js }s9 s Zt 8ZtIB IBtI }B Zts % 9 jBR YB8A R I {BjB j$I st s js s9s Ajst{s t js $tR sZ s{$? Bt I j B I t RB{$sj et qY 7 {BtI * jZ >d d1H I ps _ 7 %$RR js $t8 R$? Bt I js q$ s t Zts t AZjBRs ABRst I s Zs {ZA {B8}j s8 t RZ RZ} h{$ %s $sR 8$jjsR qs8A$? t j } Bj? h{B FBYt GktIYs8 sAB Is js $tZtIs{$? Bt I js q$ s t s, t s{ {Ys >qY s, t Gs, R d xnH IBtI js $t%sR$? Bt I ZtsR { $s Z sR I jsR } BPZtI$IsI R 8s $tsR {Zj8$ts {Bt js PZR$? Bt I jBR Y$ jBR }Bjs R eR} {$sj8 t {? j A R j $t${$B I j {$ t hj8 Gs bB jI IBtI j YsT A$ Zsj jB B $}B I js {B8}sK t? s =t$% Rsj _${ Z R j } $8 }jstB I j }jst s q$ s RBA j PBtIB I R jjsR Is }sRB s Zt 8ZtIB st sIB JZ 8$ts }B {ZA $ R }j ts8 t sR j I {j$% I jBR Y$ jBR }Bjs R =ts } R} { $%s I sj{st{ jB{sj R js A $tIsIs }B NsR B R I j Bj%$IB >qY * Bbt$t qBb R d M H I p B qZ t IBtI j j t B sR{ tRB I j t$% j I jBR B{? stBR } B}${$sIB }B j P { B $t% tsI B R }Zj s }s {$sj8 t VZR sj$s k sj ZtsR {$ZIsI R {BR sR Zts {s ? sR BP 8? sR s{B I {Bt jsR R $8s{$Bt R I j sZ8 t B I j t$% j I j 8s t {sRB I PZR$? Bt I jBR Y$ jBR }Bjs R ! BR P t? B8 tBR 8 B Bj? B ${BR B BP? R${BR Yst {Bt $AZ$IB s s $ s js %$Is t js q$ s q T 8B BR {B8B jBR JZ I R Zk t ]sj$PB t$s t js tB% js I V YZ ] ]js , ej 8s $jjB I *$BR >qY <s88 BP pBI d xH B t i${Y d( >d EH B s I RZR {$ t R { s{$Bt R t {BjsAB s{$? Bt {Bt $, {+Zsk VZtJZ Ys R$IB j {$t {Bt RZ s8}j$B I R}j$ Z I P {T BR R} {$sj R j 8 I$B JZ Ys {s s}Zj sIB R $}B I I s8sR YZ8stBR {B8B t j hj8 q 8B B >es YJZs, d ;H JZ ts s js s}B{sj? } ${s I R Z{{$? Bt I js {$ZIsI I NBR VtT
! B - sK tB sR {BtR $ Zk j N $ 8B $% I j js B Ns s 8? BRP s t% t tsIs >qY _B$RBt h{B V YZ ]Btst *Bkj U sR BAR %s sj s{$Bt R t j R} { B I js sI$s{$? Bt j d dnH I j } Bj? RBjs j } BP RB ]Ysjj t RBR $ t JZ js q$ s Ys { Z9sIB Zts }B {$? Bt I j R}s{$B IBtI j ? {$ {ZtIst RZj s R j sj q sR js s}s t - $t{$? Bt I js YZ8st$IsI j I s8s Is Zt $t R} sIB %Z j{BU jBR sP { sIBR }B j sR B tst s js %$Is sR Zt R sIB I }R ZIBY$A ts{$? Bt ej sR tB R ? B-${B dn
© Los autores, 2001; © Edicions UPC, 2001.
x N k tIsR I Zt }jst s jjs8sIB q$ s
1;x
3$ x M wV $AsD s $t j 8Z st YZk tIB s AB IB I RZ $8s ? st I j s{BRB I PZ $%BR R8B, R wVAs`BD ej V Bj? Bt js {$ZIsI 4B st Z ?j $8B PZ $B I js YZ8st$IsI * j hj8 Gs bB jI >Gs bB jI d xH
© Los autores, 2001; © Edicions UPC, 2001.
1;E
* $t Bt s e$tR $t
j R t Zt {BjBRsj R ? R8B Z R sR I j RZ $ I j {$t I {s ? sR BP R I htsj R I jBR ( jB {BtR $ Zk t ? ZjBR {B8B qb$R >qb$R d EH IBtI $ ? st${BR B tsIBR s sRst j {B s9? Bt I WB s8? ${s B =t }Z AjB jjs8sIB *st :R _ s, >*st :R _ s, d EH Zt hj8 I s{{$? Bt Y I B I jBR js BR RBA js Y$R ? B ${s I R Z{{$? Bt I js {$ZIsI I _B8} ks JZ I R{ $A j }? st${B RZR{$ sIB }B Zts } t $ts Z}{$? Bt %Bj{? st${s qs8}B{B - t sR I $tR}$ s{$? Bt A? Aj${s R t{Z t st jsR RZ $j R }js sR k tP 8 IsI R JZ Yst I$ 98sIB js %$Is t js q$ s Ns } B}$s Y$R B $s I js YZ8st$IsI R t{Z t s Rsj}${sIs }B R$t$ R sR tP 8 IsI R I RI js 8$Aj } R t s %$R$ sIs t ej j$A B I j I? s I j FZ${$B 3$tsj >*BB8RIsk BB, d 1H I ]Btt$ G$jj$R }sRstIB }B $tP {{$Bt R %? ${sR I$% RsR YsR s jj s sj R$Is j s9B I jBR ( =ts I jsR } $8 sR tB% jsR %$t{ZjsIsR sj ? t B R ej Z ?j $8B YB8A >qY NsR st dM1EH I s k 7Y jj k IBtI Zts }js s JZ {B eZ B}s I RI ! $ t I$B I `s {Bt %$Is s Zt Z ?t${B YB8A yI s B8sIs }B sj ZtBR hj8 R I j } $8 {$B I R R$ jB {B8B NsR st Bt es Y >d 1;H B RZ 8s, y :R p s B A Vj$% >d nnHU Zts - sK ts tP 8 IsI - 8$ts s BIBR jBR %s Bt R I js q$ s -{ } B s Zt sPB ZtsIB JZ }sRs s R {BI${$sIB }B BIsR jsR P? 8$tsR I j }jst s Fs{, NBtIBt -}jB s js } R} { $%s {? {j${s I js Y$R B $s YZ8sts t qY 7{s j _js Z >d dxH IBtI {$%$j$9s{$Bt R } $8$ $%sR B8st j j %B I RB{$ IsI R {t$h{sIsR sR Zt YBjB{sZR B ej ? t B sj{st9s Zt }Zt B s ?j $IB {Bt p B i 7 bs k RZ Ns q$ s } 8st { >es Y VA$I R d ; HU Zts - sK ts }js s I js JZ R? BjB RBA %$% ZtB I {sIs 1x( ((( R R YZ8stBR Ys I$ 98sIB js }BAjs{$? Bt sZtJZ } R %stIB js PsZts k js 4B s R R ej } B s Bt$R s j$I s Zt Z}B I RZ} %$%$ t R t 7st 3 st{$R{B BA{ {sIB }B stR8$ $ j {BtB{$8$ t B js $t st $Aj Y t{$s I js YZ8st$IsI yt{$ B PZ Z B s Zs Is s8A$? t sj -$ ZB Z}B I RZ} %$%$ t R I {stBR{ $ B I j R ZtIB B $ t > {stBR{ $ I j R Bt B $ t d ;H I stZ j I _ I BjB sR js } t $ts - $t{$? Bt I Zts YZ8st$IsI As $Is }B Zt - sK tB $t -}j${sAj P t? B8 tB qs8A$? t js { j A sIs ej I? s I jBR ? hIBR >qY *sk BP Y q $^IR d xdH I FBYt GktIYs8 tBR s{ {s sj % IsI B $8}s{ B }R${Bj? B ${B I Zts YZ8st$IsI JZ }$ I js %$R$? Bt sR Zts - sK ts jjZ%$s I 8 B $ BR } Bj ? B8 tB I Zts }js s I }jst sR % t tBRsR s? Zt 8? sR 8B ? P s jBR ? hIBR JZ I Rs st RZ }s ${Zjs { Z9sIs {Bt s js YZ8st$IsI _ R s js j %sIs {sj$IsI I js tB% js RZ YB8? Bt$8s sIs} s{$? Bt {$t 8s B ? sh{s I d En tB R ? s s RZ sj Z s et jjs jBR 8$Aj R ? hIBR 8$tst }B RZ{Z8A$ s Zt 8B sj {? B{ jU g j s Zs I j 8s wzsj JZ R ? RZ{$s } B D ej j sj %$ ZR I Ns 8Z I js Y$ As >qY * s Y BP p sRR d xEH wsIs} sIs sj {$t {B8B WB jsI BP p sRR >d (HD I RZ I$R{? }ZjB FBYt ]Y $R B}Y s sRs BIsR jsR {BR {YsR JZ t{Z t s s RZ }sRB 8ZjstIB jsR YB IsR I V $js et Zt BtB BIs%? s 8? sR - 8B $st G VjI$RR }jst s t s As ? R >p kA s I d E;H jsR BR{Z sR } R} { $%sR I Zts YZ8st$IsI sJZ `sIs I Zts R $j$IsI $ % R$Aj JZ {BtIZ{ t sj B{sRB I j YB8B Rs}$ tR ! s {jsR I }js s R js sAB IsIs }B ${Ys j ] ${Y Bt t Ns s8 ts9s I VtI ? B8 Is >qY t ${B ? ZjBD IBtI Zt VtI B8 Is 7 s$t d E H wjj %sIs s js st }st sjjs t d d {Bt $I? %$ ZR I B $ t - s R $ Z8} t tZ R s s 8? BRP s $tsI% $Is8 t t j R tB I Zts ts% R}s{$sj JZ Rs s js q$ s et _$ I8Bt WZ %B ? -${B }BAjs{$? Bt { {sts sj jZ s I s $9s` R? BjB Zt st{$stB A $B k Zt A A? RBA %$% t s js j sj }js s I Rs sIs et js
© Los autores, 2001; © Edicions UPC, 2001.
x N k tIsR I Zt }jst s jjs8sIB q$ s
1;
3$ x wV $AsD Ns PZ 9s I j %$ t B 3B B s8s I js } j? {Zjs qb$R >qb$R d EH wVAs`BD ej Z ?j $8B YB8A t AZR{s I } RZt BR {Bt ? t R 5%$%BR2 * js } j? {Zjs ej Z ?j $8B YB8A %$%B >qY !8 s st d dH
© Los autores, 2001; © Edicions UPC, 2001.
1;M
* $t Bt s e$tR $t
8$R8s j? t s ej -} $8 t B I j * +Zs 8sRR >qY +Zs 8sRR } $8 t d xxH ts s j Ps sj I R tjs{ I Zt sR BtsZ s JZ sIJZ$ Zt %$ ZR sj$ t? ts IZ st Zt %Z jB R}s{$sj ej } B}$B +Zs 8sRR t Z sj$9s sj YB $Aj sR BtsZ s 8Z sIB t }j ts {s I sj I G R 8$tR t ZtB I jBR htsj R I } j? {Zjs 8? sR s}B{sj? } ${BR JZ R {Z Is ! s 8 8B sAj tB% js I j ? t B 7Bk j k tIs >y V8 N tI d x;H I i${Ys I s Y RBt jj s $t{jZRB s js{$Bts j B $ t I j %s8}$ $R8B {Bt Zts - sK ts tP 8 IsI As{ $sts JZ }s { } BIZ{$ BIBR RZR P { BR NsR YB IsR I %s8}$ BR $t t st Is {s9s sj Z ?j $8B YB8A s` tB sj %$ ZR JZ R %$R B {B8B Zts % IsI s s8 ts9s Zts s s s%$R JZ Ysk JZ I R Z$ s BIs {BR s }s s R sAj { js YB8B t $IsI RB{$sj _s sIB`sR I j I R $tB js tP 8 IsI R js tB 8s t R js B JZ sAB Is j s{BRB R$R 8? s ${B s jB I R{BtB{$IB I RI Zts } R} { $%s st $tZRZsj {B8B $tJZ$ st @; VZtJZ tB BIB R ? s } I$IB }s s js YZ8st$IsI s G$jY j8 t js {Z $BRs *BtI RBj? st {st s jBR IZj{ R }? s`s BR >GY t Ns Y 7b $ IR 7st d EH s}B s Zts $t Rst RBjZ{$? Bt s js }BAjs{$? Bt I Zts q$ s I$ 98sIs sR Zts {s ? sR BP {Bj? B ${s R$t } { I t R Ns {$ t{$s I `s sJZ? I $t } s j }s} j I % IZ B I js YZ8st$IsI }s s {Bt% $ R t R stIs I RZ {Z} s{$? Bt t % IsI B j$-$ I js %$IsU j {Z RB I js {jBts{$? Bt YZ8sts sIJZ$ sR? $t R R t{$sj R }s s %$ s j ht I js R} {$ gOs R ? st sJZ? ] ? Bt${s I Zts $t%sR$? Bt
NsR 8BI tsR R}s{ TB} s RBA $t%sR$Bt R - s R R $ t t RZ B $ t t jsR }s stB$sR RZ $IsR sj Zt? RBtB {Bt j ts{$8$ t B I j {$t ej 8B s Zts Z s PZ Z s t{s tsIB $t${$sj8 t t js }B t{$sj $t%sR$? Bt I p st sK ts }B }s sj 8sts RZ}Bt B B ` 8}jB I j hj? Bt t{Bt sIB }B j ? t B t jBR 8$ IBR {Bj { $%BR {B8B j ks 8 t{$BtsIB 8B s ? B8${B V qY V$ RY$} * R Bk >d ( H j {B R}BtI j } RZt B YBtB I R js } $8 s } j? {Zjs RBA js $t%sR$? Bt I jsR {BR sR $t j RsR }B Zt `? {$ B {tBj? B ${s8 t s%st9sIB %$I t{$s I R 8B ts{$Btsj s%$%sIB I RI jBR 8 I$BR I {B8Zt${s{$? Bt =t 8$ IB s9Z9sIB }B } j? {ZjsR {B8B qY V $sj Vts {Y$R R >d ddH }$Bt B t 8BR s t }st sjjs js I R Z{{$? Bt I 8BtZ8 t BR k I$h{$BR {BtB{$IBR ]Bt R hj8 js $t%sR$? Bt sAstIBts RZ {BtI${$? Bt I Z8B %s B k st? Bt$8B }s s $ $ R t Zts } RsI$jjs {Bt tB8A k s} jj$IBR Vj $ Zsj JZ j {j$8s } A? j${B JZ st { I$? B s js y pZ s ZtI$sj $tR}$ ? B s Z8 t BR AsRsIBR t Z sR PZ Z sR j s8A$ t t s {$IB I d n s jsR }Z sR I js R ZtIs {BtP Bt s{$? Bt 8ZtI$sj $8}ZjR? B js s}s ${$? Bt I hj8 R JZ 4 `sAst j YB B I Zt NBtI R I R Z$IB }B j AB8As I B t 8$ B {B8B $It$ Y ts{ >d n H B + _jst R >d n H et R s ? }B{s j 8B {B8}s $IB }B 3 st{$s k p st sK ts st js } R} { $%s I Zts tZ %s $t%sR$? Bt sj 8sts }sRs j j %B s js s{ Zsj8 t Y$A tsIs Z s P ? s t eR sIBR =t$IBR k js - $t s =t$? Bt 7B%$? ${s Ns R? B I$Is Y t{$s I js yy pZ s ZtI$sj j 8B s Zt YBjB{sZR B s ? B8${B k js }s stB$s I $t R - t? BPBABR I R 8AB{s t I s8? s ${BR }$RBI$BR {B8B js $R 8 t {? j A {s9s I A Z`sR Ns tB% js I s Y RBt Ys RZP $IB I$% RsR sIs} s{$Bt R {$t 8s B ? sh{sR I R{sRB t$% j {B8B N:Zj $8B ZB8B I jjs q s >d E;H k ej Z ?j $8B YB8A %$%B >qY !8 s st d dH d;
© Los autores, 2001; © Edicions UPC, 2001.
x N k tIsR I Zt }jst s jjs8sIB q$ s
1;
t tBRB BR eR stIs k s JZ $}B I Rs } RsI$jjs BAR R$%s R js t$sj Ns $t%sR$? Bt I jBR jsI Bt R I {Z }BR >yt%sR$Bt BP Y BIk 7ts {Y R d xEH AsRsIs t js tB% js qY BIk 7ts {Y R >d xxH I Fs{, 3$tt k k JZ Ys R$IB BA` B I IBR RBA $BR 8s, R Ns $t%sR$? Bt I jBR Zj s{Z }BR >yt%sR$Bt BP Y BIk 7ts {Y R d EH k BIk 7ts {Y R 7 {Z R sIB R I {Z }BR >
$8}ZjRsIs }B j R tsIB s8 ${stB FBR }Y {]s YkU js $I s I JZ j t 8$ B R t{Z t s
BIk 7ts {Y R d nH eR 8$ IB t sj$9sIB s I { s t 8$ BR IBtI tB jBR Ysk $8}ZjRs
RBA 8st s jBR tZ8 BRBR s%$R s8$ t BR I B%t$R JZ $tZtIst js I? {sIs I jBR x(
@N
ej {j$8s
I js ? }B{s R B ts } j$ BRs8 t } ? B-$8B sj R t $8$ t B - t? BPBABU YBR $j$IsI st {ZsjJZ$ PB 8s $I BjB ? s B {BtI${$? Bt {Bt s $s s jBR {? stBt R R sAj {$IBR VR ? $t{jZRB jBR sj$ t? tsR
JZ t js h{{$? Bt jj st s js q$ s t RBt I }s9 {$A t Zt %$Bj t B k I R8 I$IB %s s}sjB =t ` 8}jB 8Aj 8? s ${B jB {BtR $ Zk
=j $8? s Z8 s js q$ s >qY *sk Y es Y 7 BBI 7 $jj Vj ZtBR { ? ${BR Yst jj sIB s
d xdH Zts BIs 8B sj RBA jBR -{ RBR I js t ? s s ? B8${s
JZ$}s s sj $tR$ t sj$ t? ts jss Z {Bt js h Z s I ] $R BU sj $ Zsj JZ RZ{ I ? s sK tBR 8? sR s I {Bt
e q j - s R
>e q Y e- s R $sj d M1H jss Z 8Z s 8stBR I
jBR YB8A R
k RZ{$ s sj s8}s B I RZ h j stI B$I pB
RZs% R 8BIsj R I }s s RZ 8ZtIB B
qY st P B8 _jst >d xdH JZ s{ZI s js q$ s t AZR{s I sZ-$j$B jBR sj$ t? tsR I y ]s8 P B8 !Z 7}s{ >d xnH JZ B8st } R sIBR
@-
qs8A$? t j - s R I
{Z }BR YZ8stBR {Bt j $tBP tR$%B } B}? BR$ B I 8}j s jBR {B8B 8stB I BA s }s s }s s RZ ts% s% $sIs {BtR $ Zk t 8Z R sR I j t? R$8B {$A$8$ t B YBR $j u- t? BPBABu I js ? }B{s Ns RBA I$8 tR$BtsIs R}Z R s YZ8sts }BR$Aj 8 t j R Ysks jj %sIB s } BY$A$ PZ Z sR %$R$ sR s Zt 8ZtIB st A? s As B
Ns }s t sZR t{$s I 8B{$Bt R t j s B {Bt jBR sj$ t? tsR {BtR $ Zk B B 8st$IB {Z RB
$t%sR$? Bt I jBR jsI Bt R I {Z }BR B yt%sI R P B8 s R >d xnH
I 8Z{YBR hj8 R RBA {Bt s{ BR B $t%sR$Bt R - s R R VR ? } j ? {ZjsR {B8B js {$ sIs
Ns
} R t st s sj$ t? tsR JZ
} B}Bt t s js YZ8st$IsI sj{st9s Zt R sIB I }Z B $t j { B {Bt Zt {B s9? Bt {ZksR PZt{$Bt R R j$8$ t s jsR I 8 B 8B B A$Bj? B ${B s` tB s BIB I$R Z A$B 8B{$Btsj w$I s tB 8Zk I$R st I jB JZ js RB{$ IsI tB s8 ${sts t ? s t js ? }B{s RBA j {B8Zt$R8BD ej hj8
yt%sI R P B8 s R I {$ t %$R$? Bt wyt%sRB R I s >yt%sI R P B8 s R d MEHD } R t s Zts js $I t $IsI I Zts 8$ ? sIs I R R YZ8stBR st js }sR$%$IsI t sj Ns RZ}jst s{$? Bt
RZ $j PB 8s I $t%sR$? BtU jBR sj$ t? tsR jj sIBR t Zts ts% R}s{$sj ZRZ }st } B R$%s8 t
}B PB Zts }s s j P j$9 I R tjs{ I js Y$R B $s tB R } P { sU `Zt B s js {$ sIs sZR t{$s I 8B{$Bt R jsR {B}$sR } R t st Zts I js B s 8s {s t js tZ{s t PB 8s I w5js h 8s I j
qY _Z }j BtR 7 $, R >d ;xH }$Bt B t RZ ZRB }sR? B j j %B s B sR } BIZ{{$Bt R {B8B +Zs 8sRR yy >d xxH qY s$t es R >d xMH B y ]BtJZ I Y GB jI >d xEH {Bt ZtBR % tZR$stBR B I R t PB 8s I } }$tB et y s $ I B9s I s8}j$s sI${$? Bt t j ? t B
s $R s2D * Y {YB j s JZ $}B I $t%sR$? Bt RZ $j {Bt RZ}jst s{$? Bt } B R$%s I js YZ8st$IsI
@N
BA` BR %Bjst R tB $I t $h{sIBR @-
]Z $BRs8 t $ tB sIBR t BIsR jsR I? {sIsR st $B R * Y {YB j } $8 s%$R s8$ t B I Is s I d ; gsK tB t j JZ % t{$ Bt sA$ s8 t RZ $8$I 9 wR${D
=ts tB sAj I$R{ }st{$s {Bt j js B t j JZ R AsRs =j $8? s Z8 s js q$ s >qY *sk Y es Y 7 BBI 7 $jj d xdH ej s8B Ys 8Z B >3s b jj B Y sR d ;(H I <s k s R R j `Z B I }BI t jBR } B s Bt$R sR et j $t R} sIB htsj I j js B pB R % js {B8B j % IsI B s8B I Zts ? j$ I R R 8 {? st${BR JZ %$R$ s js q$ s t {B8}sK t? s I RZ { $sIB g jss Z
© Los autores, 2001; © Edicions UPC, 2001.
N
* $t Bt s e$tR $t
3$ x d( wV $AsD ej $8}Bt t BAB pB k js Y B? ts I =j $8? s Z8 s js q$ s >qY *sk Y es Y 7 BBI sR${B }js $jjB %Bjst wVAs`BD Ns -} I${$? Bt {$ t ? h{s {Bt 8}js sj 8$R $BRB 7 $jj d xdH t j $t $B I j {j? sj$ t? ts {ZA$ B I Y$ jB }Bjs I ej t$ 8s I B B 8ZtIB >qY qY$t d xdH
© Los autores, 2001; © Edicions UPC, 2001.
x N k tIsR I Zt }jst s jjs8sIB q$ s
N@
s BtR P B8 !Z 7}s{ 8ZtIB I {sI t
>d xMH { $ ${sIs }B RZ 8s {sIB st ${B8Zt$R8B jBR sj$ t? tsR
`ZR $h{st js RZ}jst s{$? Bt I YZ8stBR t Zt $t t B I - tI RZ } Bj k sAstIBts RZ ? sR {$ t 8 t
geR ? st %$%BR
>qY k N$% d MMH Zt YB8 ts` s jBR
hj8 R I jBR sK tBR x( $9s j $9B I jsR Y$R B $sR I $t%sR$? Bt ZA${stIB sj R$t Zjs t 8$ B t }Z R BR R s ? ${BR qs8A$? t js j %$R$? Bt s s%? R I js JZ PZ s }B}Zjs R $
$t%sRB R
NBR
>qY yt%sI R d E TEMH R s}Zt ? B s js 8BIs I js $thj s{$? Bt I Zts s9s sj$ t? ts
t tZ R s RB{$ IsI NBR {Z $BRBR $t%sRB R R I js sAst }B Zts AZ Is $8} P {{$? Bt t RZ I IB 8 K t$JZ JZ tB }BI ? st 4 -$Bts {Bt% t$ t 8 t ]s t I Zts RBA $s j? t s s Z8 t sj jsR IBR 8}B sIsR I js R $ R { t s Bt t jBR $tP Z{ ZBRBR $t t BR }B % js j {Bts B I $t%sR$? Bt s jsR sZ B $IsI R I RZ } R t{$s *$P? {$j 8} Rs }B {Zst B jBR sj$ t? tsR tB I `sAst sR B
yt{jZRB sj 8B $ RZ {Z }B R I R%st {? s I `stIB Zts Z ?t${s }$ s I { t$9sR qs8A$? t jsR I$P t R R $ R }s sj jsR I j Zt$% RB q , Yst Y {YB
{B8B R K tsj I RZ }sRB
ZRB I R s RZ}jst s{$? Bt YZ8sts t }$RBI$BR {B8B
q ,U js tZ %s t s{$? Bt
]BtR}$ s{$? Bt
>]BtR}$ s{k d MMH I
7 s
>7 s q ,U qY W - p t s $Bt d M T ;H IBtI ZtBR I$8$tZ BR
sj$ t? tsR jj st $t{jZRB s $thj s R t j R tB I j {Zs j t sj I js 3 I s{$? Bt * RI Zt }Zt B I %$R s j$ s $B j 8skB -}Bt t R sj{st9s }BR$Aj 8 t {Bt
V8BR I ? R
>qY
_Z}} sR R d xdH R{ $ s t }j ts Z s P ? s }B iBA V < $tj $t Ns tB% js ts s js $Aj As sjjs j$A sIs }B js YZ8st$IsI t j sK tB 1(( {Bt s Zts s9s I R R js $tBRBR } B{ I t R I q$ ? st JZ R h`st t js tZ{s I RZR %? { $8sR stZjstIB RZ } RBtsj$IsI
3 Z B I Zts {Z $BRs {B$t{$I t{$s 8$ t sR jBR tB s8 ${stBR 8$ sAst {Bt { jB sj {B8Zt$R s I js =i77 j {$t ZA${sAs } {$Rs8 t t j }jst s t? Z8 B I $t%sR$Bt R - s R R {B8B t js {j? sR${s GB jIR d xnH
} j$ B B`B s s Zt AZ t Ns Z s I jBR 8ZtIBR >Gs BP Y
sRsIs t js tB% js YB8? Bt$8s I < p G jjR }ZAj${sIs t dM M js % R$? Bt
{$t 8s B ? sh{s sRjsIs js s{{$? Bt I js yt js s I dM ( s js ]sj$PB t$s I d xn k 8}js9s jBR stR}B R 8s {$stBR ? } IBR }B %$R BRsR R Z{ Z sR %BjsIB sR jj sIsR s js q$ s s AB IB I 8 B $ BR ej {Z $BRB htsj I js } j ? {Zjs w}js $sIB t js {$ t
*sk
ytI } tI t{
>d EHD sA Zts }Z s s js - s}Bjs{$? Bt A$Bj? B ${s k JZ$9? sR js {s`s I _stIB s I Zt JZ sP Bt s t js
Bt }s s jsR } BIZ{{$Bt R {$t 8s B ? sh{sR2D tZ %B } j$ B w5k Zt tZ %B hj?
{BjBt$9s{$? Bt I B BR 8ZtIBRU } R s R$R $ $8}sR$Aj R j s sJZ {Bt j sj R AB8AsR s ? B8${sR jBR 8s {$stBR RZ{Z8A t st R$8}j R As{ $sR I js s 8? BRP s R s {ZkB P { B tB RBt $t8Zt R
=ts I jsR tB% jsR I B $ t sj 8? st 8? sR { j A sIsR I j ? t B
VZP 9b $ _jst t
>dM H I
Z NsRRb$ 9 ts s s8A$? t j tP t s8$ t B I js YZ8st$IsI {Bt Zt `? {$ B 8s {$stB {tBj? B ${s8 t s%st9sIB {Zks } R t{$s s AB IB I Zts R s{$? Bt B A$ sj st{jsIs t ZtB I jBR }BjBR R R tB R R$tB j } B 8$B I Zts RZAB I$ts{$? BtU js q$ s }sRs s {BtR $ Z$
Zt } B { B sIB 8s {$stB * R s{st sR$8$R8B IBR R? s $ sR RBA js $t%sR$? Bt 8s {$sts I 8Zk I$R $t s ? tIBj et
g s {$stB % s {sRs
> s $stR pB <B8 d xxH I 3 I ${
Bbt Zts
j $? Bt I } JZ K tBR YB8A {$jjBR % I R RZ8s8 t hR Bt R $8} $t t R jj s s tZ R B }jst s %Bj%$ tIB jB{B sj } RBtsj Ns {$ t
s R V s{,R
>d EH ts s s8A$? t js jj sIs $ t sR j BA$ tB R
I %$Bj t BR 8s {$stBR JZ } tI t s}BI s R I js q$ s
$t t s h 8s js }s9 R$ tIB I B sIB t IBR B{sR$Bt R }B jsR YB IsR 8s {$stsR Zts R$8}? s ${s sAZ js R {Bt%$ t $t R} sIs Y B ? ts I js R$R t{$s YZ8sts _Zt B k s}s 8 { B s
© Los autores, 2001; © Edicions UPC, 2001.
N
* $t Bt s e$tR $t
3$ x dd 7 I$ t BR sj$ t? tsR I }sRB }B js q$ s
I jsR `BksR I js R $ I jBR sK tBR x( i I _jst s R >d x1H t js JZ Zt JZ$}B I {$ t ? h{BR RB%$? ${BR skZIsIB }B Zt } RZt B R}? s ts9$ $t t s B{Zj s s js RB{$ IsI Zt $Aj R { BU gjBR 8s {$stBR RBt { $R $stBR et j R}s{$B tsI$ }Z I B? ZR $ BR _ B t js q$ s R? ]sBR Y$R $s {Bj { $%s {s s{ $9st jsR {BjBRsj R $t%sR$Bt R - s R R I j ? t B {Bt ` 8}jBR {$ t R {B8B ytI } tI t{ *sk $tR}$ sIs t js ts[ P es Y % RZR Y 3jk$t 7sZ{ R >d xEH ! s R $ I j %$R$? Bt z >d MnTMxH I R{ $A js 8Zj $ ZI$ts $s jj sIs I ts% R sj$ t? tsR {Bt $}Zjst R YZ8stB$I R {ZkB t$sj I$RP s9 R{BtI s }ZjR$%BR $8}js{sAj R js s BR Ns R$R t{$s YZ8sts sj t sIs }B { t ts R I z JZ t R K tsj I %${ B $s $tZtIst 8Z BR k Ps{YsIsR I jBR I$h{$BR I BIB j }jst s tB R Ys{ R} s tBR s R$%BR s } $B $ RZj st jBR sj$ t? tsR I js tB% js NBR tB{$IsR >qY p tB{$I R d ExH I qYB8sR *$R{Y 8} K tsIBR t R 8A s js q$ s {Bt ZtBR % sj R JZ stRPB 8st j }jst s t Zts 8BtB{Zj Z s s ? {Bjs NBR - s R R 8$tst }B % s jBR 8Bj R BR R R YZ8stBR {B8B 8 BR ZRstBR I Zts 8st9sts k BA stIB t {BtR {Z t{$s 8$tst gPZ8$ stIB j }jst s ! BR {Bts BR I $t%sR$? Bt s 8 tB R{sjs s {s B I s Z $IBR - s R R t %$R$ s -T }jB s B $s B {s? IBR }B s9s Yst }BAjsIB }? s $tsR k 8 BR I { jZjB$I ej t$ 8s I B B 8ZtIB >qY qY$t d xdH $tR}$ sIB t j $tJZ$ st js B I FBYt G ]s8}A jj 5+Z$? t Ysk sY? 2 >GYB pB R qY 2 d nMH I R{ $A j Ysjjs9 B I Zts ts% sj$ t? ts R }Zj sIs t jBR tBR Y$ jBR }Bjs R e- s? Is I j Y$ jB Zts { $s Z s sj$ t? ts 8}$ 9s s I$ 98s js -} I${$? Bt {$ t ? h{s 7Z tB sAj 8s, Ns {BRs >qY qY$t d M1H B8s j js B B $ $tsj $t{B }B stIB s Zts R? B I$Is { $s Z s {s}s9 I 8Z s RZ sR} { B s {ZsjJZ$ PB 8s $t$8s $T tsAj WB 8 tBR $tJZ$ st R RZj st jBR sj$ t? tsR I * } IsIB >_ Is B d M H R R s R$%BR s s%$sIBR s js 8BIs sR s JZ st$JZ$jst }B }js{ Zt {B8stIB I 8 { ts $BR JZ
© Los autores, 2001; © Edicions UPC, 2001.
x N k tIsR I Zt }jst s jjs8sIB q$ s
1xn
jZ{Ys {Bt s js Z $jjs t 7ZIs8? ${s 7Z R {Z js
* } IsIB 1
>_ Is B 1 d (H } R t s j {Bj {{$Bt$R8B I { ? st BR
s B B sj$ t? ts t sIB s js } ? s{ ${s I RZ I }B Ps%B $ BU w{Bt Zt t$sj Z$K tB s
Vj$ t j B{ s%B }sRs` B
>Vj$ t d HD t js {$ZIsI I NBR Vt j R t
}j ts k s t ts {BR `s8s${stBR {BjB8A$stBR k j 3 ts% B I {$I sj s j {Z RB I js Y$R B $s t
7 s q ,U } $8 {Bt s{ B
y ? sR {$ t 8 t Zts 8$Aj >7 s q ,U 3$ R
]Bt s{ d EH }s $ tIB R B}s t js I R} % t$Is q$ s I j ; I sA $j I j sK tB 1(En sR sj$9s Zt %$s` t j $ 8}B
VZ ? t ${BR jBABR {Bt }$ j I {B I B RBt jBR Z AsIB R t$K tBR I } jB ZA$B k B`BR s9Zj R sj$ t? tsR I sR} { B st j${sj JZ s8A${$Btst {BtJZ$R s js q$ s t >d E(H wAsRsIB t js 8s $R sj tB% js
I FBYt GktIYs8D hj8 {Bt Zts R {Z js
ej }Z AjB I jBR 8sjI$ BR
NBR {Z{j$jjBR I $Ib${Y ]Y$jI t BP Y *s8t I N$P TPB { 3Z 9s %$ sj
z$jjs BP Y *s8t I
@
>qY $Ib${Y ]Z{,BBR d x H >d EnH k {$ t
8s,
>z$jjs BP Y *s8t I d xH _ RZt s $tB{ t{$s s{B8}sK ts s8A$? t >N$P PB { d MxH t{s ts{$? Bt
jsR B ZtIsR PB 8sR I jBR sj$ t? tsR I
sj? s{ ${s I jBR {j? sR${BR %s8}$ BR s8}s sIs t j $t8$t t }sRB I j {B8 s <sjj k WsIs JZ % {Bt j P B9 - s R I
B
>d M1H ts{$IB s js RB8A s I
Vj$ t j B{ s%B }sRs` B
! sR PB 8sR I %$Is - s R Yst R t $IB s8A$? t Zts {Z $BRs PsR{$ts{$? Bt }B $t%sI$ js q$ s et
Ns tZA t s
>qY
js{, ]jBZI d x H I 3 I <Bkj R ts s js jj sIs I
Zts 8$R $BRs t AZjBRs B}s{s I ZtBR dx( 8$jjBt R I ,$j? B8 BR I I$? s8 B k Zts 8sRs Z}$ s jsR $t8 I$s{$Bt R I js q$ s I ZtBR 1\n I js 8sRs I F? ej $8}s{ B I js tZA
{Bt js s 8? BRP s R j$A s Zts st {st $IsI I j sj R skBR k s88s JZ BAj$ s s jBR R R YZ8stBR s sAstIBts jsR $Bt R I st sj $ ZI k AZR{s PZ $B t {Z %sR k RZA ? st BR ej I s8? s ${B I R{ tRB I js 8} s Z s 8B $%sIB }B js } B}$s } R t{$s I
js tZA R sIZ{ t (( 8$jjBt R I %? { $8sR { Z j j sIB }s s j } $8 {Bt s{ B {Bt Zts $t j$ t{$s - s R et
qY jBA
>d xMH Zts 8sRs js $tBRs jj s s js q$ s
s AB IB
I Zt 8 B $ B sj stIB RZR Y? sA$ BR sj$8 t ${$BR t } `Z${$B I B{sR$Btsj R } RsR YZ8stsR 7Z sARZ Is R {Z js
ej B tB $ t PB 8s
>qY
jBA d MMH htsj$9s {Bt js $tJZ$ st ! s R? s $ s I j ? t B
% js{$? Bt I RZ B $ t R P Z B I Zt -} $8 t B R { B
? sR % I I jB JZ { ? $R ZA ts8 t sj
>p t Yst OBZ qY$t, d ; H I Gs I BB I R{ $A {? B8B
Zts PB 8s % sj 8$ts }B sARB A j 8ZtIB t B IZ st Zts $t 8$tsAj %s{$js{$? Bt
WB BIBR jBR sj$ t? tsR RBt YBR $j R I
ej ht I js $tPst{$s
_ R s RZ h B sR} { B I 8Bt? s{B jBR p stI R R K tB R
>]Y$jIYBBI:R etI d x;H I V YZ ] ]js ,
$t%sI t
}s{ ? h{s8 t js
q$ s t 8$R$? Bt I Z js I js s9s YZ8sts et RZR 8stBR sI${s j I R $tB I js YZ8st$IsI t jsR R jjsR qs8}B{B js {Bt%$% t{$s {Bt jBR n(( ((( sj$ t? tsR JZ jj st s NBR Vt j R t d d t j hj8
Vj$ t Ws{$? Bt
>Vj$ t Ws $Bt d MMH RZ} %$%$ t R I Zts ts% I R{js%BR
NBR $tJZ$ st R t$K tBR sj$ t? tsR I z$jjs BP Y *s8t I >d E(H RBt j RZj sIB I Zt - sK tB s}s s8$ t B t YZ8stBR k sj$ t? tsR JZ %$Bjs jsR 8? sR R$8}j R j k R I js t? ${s yt{jZRB R} {$ R I Zt 8$R8B }jst s js $%s8 t sht R {B8B j YB8A k j 8BtB RBt $t{B8}s $Aj R t? ${s8 t * `stIB s Zt jsIB R sR} { B RZj s RB } tI t j }s t $t ? R I sA st R t $IsI R sj$ t? tsR }B jsR P? 8$tsR YZ8stsR 5V{sRB sj Z$ t Ys R t $IB Zt I R B $ P tsAj }B {B `s Zt R{s sAs`B B Zt jst BR $tB2 wet {sRB sh 8s $%B {BtRZj {Bt RZ 8? I${B I {sA { s D d
© Los autores, 2001; © Edicions UPC, 2001.
1x;
* $t Bt s e$tR $t
s{{$I t sIs RZ}Bt Zt IZ B Bj} }s s js s9s YZ8sts _ Bt B jBR sj$ t? tsR }sRst s I R 8} K ts s sR JZ jBR 8Zjst {Bt jBR } B}$BR R R YZ8stBR 7Bt {Bt sIsR -{ }{$Bt R s js ? Bt${s YsA$ Zsj I t Bjs sj$ t? tsR $tBP tR$%BR t } j? {ZjsR I 8? s ${s { {sts s js {B8 I$s {B8B 7 s 8st >7 s 8st d M;H JZ sIB} s js $I t $IsI I Zt YZ8stB Psjj {$IB t s{{$I t k {Zks RP s 8? s ${s j Rsj%s I 8? sR I Zt t Z B e q j - s R sAstIBtsIB t js q$ s }B RZR {Bt ? t R JZ }s $ Bt t ? s}$Is PZ s jBR 8$R $BRBR sj$ t? tsR I et{Z t BR t js { s PsR >]jBR et{BZt R BP Y qY$ I $tI d H JZ R sAj { t {B8Zt${s{$? Bt {Bt Bt jBR YZ8stBR s s%? R I Zt {Z $BRB I$R}BR$ $%B sZI$B%$RZsj wk s 8BIB I {s s I } R t s{$? I %Z j% t RstBR k Rsj%BR s js Bj%$IsIs $}Zjs{$? Bt I j %Z jBTd I Rs}s {$Is R$t I `s sR B ZR{ZjBR R R I WZ R BR 8s s%$jjBRBR t j $? st ZjB I jsR 8ZIsR ;( sK tBR s ? sRD jBR 8$t? sj$sIBR > s $ R tB yt{jZI I d M H JZ } R s % t$ I Zt 8B B $t{? Bt I j Zt$% RB I I${st RZ R st{$s t js q$ s s {B8As $ R} {ZjsIB R $t8BA$j$s $BR B htsj8 t jBR } B}$BR - s R R I ]B{BBt >]B{BBt d M;H k RZ R {Z js ]B{BBt j B tB >]B{BBt Y i Z t d MMH 8Zk IsIBR s {BtP s t$9s {Bt 8$ 8A BR I j ytR RB s {$stBR % tZR$stBR sZ $tBR Yst {Bt% $IB js q$ s t }s sI$R? s{B I R $tB }s s RZR $tT %sR$Bt R NsR } $t{$}sj R s t{$sR I %$s` I js psjs-$s }s { t YsA s}BR sIB I {$I$Is8 t }B tZ R B 8ZtIB s9Zj WB $8}B s jBR R$R 8sR RBjs R JZ Ysks JZ { Z9s qs8}B{B }s { } R s R 8Z{Ys s t{$? Bt sj s{Z{$st t$% j I {Bt s8$ts{$? Bt t$ sj I $B B I js {s}s I B9BtB t$ sj $t st $Aj } j$ B I Z s tZ{j s et Zts sjs-$s {Bt 8? sR I {$ t 8$j 8$jjBt R I R jjsR 5tB -$R t$t ? Zt B B I R $tB }s s jsR %s{s{$Bt R R $%sj R JZ 8 9{s js } ts2 V tB I jB JZ 8Z R st jBR hj8 R k tB% jsR I j ? t B wk j { {$ t t? Z8 B I } RZt BR st t sA $ RZR s%$R s8$ t BR I B%t$RD jsR } $8 sR {sI tsR YB j sR - s R R tB s Is ? }Z sR t tZ R B 8ZtIB 5=ts tZ %s s8 ts9s s jBR $t R R I ssR ${Y 2
x ;
* j 8s $jjB I NZ{$P sj 8s $jjB I *$BR
"_ h B } tRs JZ IBR } BP RB R kstJZ$R Yst 8 t $IB st R JZ s{ } s JZ }Z Ist jjB% }$ I sR I j {$ jB" VR? I B ZtIB R 8BR sAs j } R$I t tB s8 ${stB qYB8sR F & RBt sR R{Z{Ys j $tPB 8 8$ $IB RBA js {s? Is I Zt 8 B $ B t WZ %s yt js s ]BtT $tZs8 t R } {$}$ st RBA js q$ s k B BR }jst sR I j 7$R 8s 7Bjs BA` BR st R } B{ I t R I j R}s{$B - $B * Y {YB js {$ t {Bj$R$? Bt I jBR 1d P s 8 t BR I j {B8 s Z}$ s{s {$Is t `Zj$B I d ; Ys {Bth 8sIB k _\7YB 8s, TN %k {Bt js RZ} h{$ I F? %$ sj$9sIB j 8B I Zt }BR$Aj $8}s{ B {Bt js RZ} h{$ R ej $8}s{ B {Bt Zt {B8 s B Zt sR B$I {BtR $ Zk Zt ` 8}jB tB sAj I j }B t{$sj I I %sRT s{$? Bt JZ BI s js q$ s Ns 8skB }s I jBR {Z }BR JZ R } {$}$ st {Bt s tZ R B 8ZtIB s9Zj R {BtRZ8 t I A$IB s js j %sIs P ${{$? Bt {Bt js s 8? BRP s R !{sR$Btsj8 t sj ZtBR I R BR BA` BR RBt jB RZh{$ t 8 t stI R {B8B }s s s s% Rs js s 8? BRP s R$t I R$t s R {B8}j s8 t k jj s s $8}s{ s {Bt js RZ} h{$ R NsR {BtR {Z t{$sR I Zts {Bj$R$? Bt I R sR {s s{ ? R ${sR RBt s} {$sAj R t j { t ts I { ? s R 8 B ? ${BR {BtB{$IBR t js q$ s I t jBR {Zsj R I R s{s j I tB8$tsIB { ? s B B R$ ZsIB t j I R$ B I V $9Bts t jBR eR sIBR =t$IBR Zts 8BtZ8 t sj I } R$? Bt I d!1(( 8 I I$? s8 B
© Los autores, 2001; © Edicions UPC, 2001.
x N k tIsR I Zt }jst s jjs8sIB q$ s
NN
3$ x d1 w8TT )ID y8}s{ B I j P s 8 t B ] I j {B8 s _\7YB 8s, TN %k {Bt js RZ} h{$ I F? Z}$ 3B B sP? s B8sIs j d I `Zj$B I j d ; ej {B8 s {BtR$R ? s t Zt t I 1d P s 8 t BR I$R $AZ$IBR s jB js B I d d 8$jjBt R I ,$j? B8 BR ZtsR R % { R js I$R st{$s t js q$ s k js NZts w8)I<*D y8s t I j { ? s B B t V $9Bts
© Los autores, 2001; © Edicions UPC, 2001.
N-
* $t Bt s e$tR $t
k Zts } BPZtI$IsI I d x 8 qs8A$? t js I %sR s{$? Bt I js $? Bt R$A $sts I qZt ZR,s } BIZ{$Is j n( I `Zt$B I j sK tB d (M R s $AZk sj ? stR$ B I Zt 8 B $ B * Y {YB R? BjB t R R$ jB Ys YsA$IB B BR IBR $8}s{ BR tB sAj RU t jBR 8Bt R 7$,YB TVj$t wiZR$sD t d ; k RBA ! ? Bt weR sIBR =t$IBRD t d 1 s RBA <s{ sj ZtBR sK tBR jBR {$ t ? h{BR NZ$R k Gsj Vj%s 9 wd M(D I$ Bt s {BtB{ RZ B ? js }BR$Aj {sZRs I js - $t{$? Bt 8sR$%s I js %$Is R s{s {$Is Ys{ ZtBR Ex 8$jjBt R I sK tBR w t }s ${Zjs js I Rs}s ${$? Bt I jBR I$tBRsZ $BRD Z R s I jBR P { BR I %sR sIB R JZ s{B8}sK tst s js {Bj$R$? Bt I Zt sR B$I B {B8 s {Bt js q$ s RZ B ? s s $AZk js - $t{$? Bt sj $8}s{ B I Zt {Z }B I ZtBR d( ,8 I I$? s8 BdM NsR RZ} h{$ R { s $9sIsR I 8ZtIBR R$t s 8? BRP s {B8B {Z $B B js NZtsd RBt % IsI BR $R BR Y$R ? B ${BR I j {Bt $tZB AB8As I B {? BR8${B sj JZ Yst R sIB RB8 $IBR jBR I$R $t BR {Z }BR { j R R I RI ? }B{sR 8B sR =t 8ZtIB }s sI$ 8? s ${B jB {BtR $ Zk 3BABR j I$8$tZ B Rs ? j$ 8s {$stB {ZkB $8} R$Btst { ? s 7 $,t k I } RZt B B $ t 8 B ? ${B }BR Zt I$? s8 B I d( ,8 {B8}s sAj s jsR I$8 tR$Bt R I j } B}$B }jst B$I NsR $ st R{sR I$8 tR$Bt R I j { ? s }Bt t I 8st$h R B {Z? st { {s Ys R sIB 3BABR I RZ } B}$s I R Z{{$? Bt !A` BR I ZtBR d( 8 I I$? s8 B {Bj$R$Btst {Bt js q$ s {sR$ {sIs sK tB P s 8 t ? stIBR k I$R$}stIB js 8skB }s I RZ t ? s JZ$%sj t s ZtBR d( ,$jB Bt R t js s 8? BRP s s d( 8 s Bt RD {YB{st {Bt js q$ s {Bt Zts ]Z }BR I ZtBR d(( 8 I s8sK tB wk t ? } $BI${$IsI I ZtBR n(( sK tBR jj stIB s {sZRs % IsI sR {s ? sR BP R I sj{st{ jB{sj {Bt s sR I I %sR s{$? ? Bt I ZtBR x3((( ,81 s? Zt R$t $8}s{ s I$ { s8 t {Bt js RZ} h{$ R w{B8B t j {sRB I qZt ZR,sD _s s JZ Zt $8}s{ B t s P { BR {s sR ? Bh{BR jBAsj R w{Bt Zts 8B sj$IsI YZ8sts R $8sIs t Zt 1x0D j BA` B I A }BR ZtsR I$8 tR$Bt R I d B 1 ,8 Ns } BAsA$j$IsI I {Bj$R$? Bt {Bt Zt {Z }B I sj R I$8 tR$Bt R R I Zts % 9 {sIs x(( ((( sK tBR _ R sj } j$ B }B t{$sj JZ t{$ st I${YBR {Z }BR R R $8s JZ js } BAsA$j$IsI stZsj I 8Z s {BtR {Z t{$s I j $8}s{ B I Zt 8 B $ B B {B8 s R {B8}s sAj sj $ R B I 8Z t Zt s{{$I t I s%$s{$? Bt wg}B jB JZ Ysk JZ R Zt % IsI B sP }s s 8B $ I Zts PB 8s st $8} BAsAj D 7$ $ tB s8BR t } $8 s s} B-$8s{$? Bt j P { B I js P ${{$? Bt s 8BRP? ${s sR? {B8B jsR % T jB{$IsI R B A$ sj R I js q$ s k I j {Z }B t Z8AB I {Bj$R$? Bt }BI 8BR R $8s js t ? s $t%BjZ{ sIs t j $8}s{ B Ns % jB{$IsI I {s? Is I Zt BA` B s s? IB }B js q$ s k } B{ T B8 BRD R I ZtBR I t I j $tht$ B wB I Zts I$R st{$s RZ} $B s sj ZtBR 8$jjBt R I ,$j? ;(3((( ,8bY JZ$%sj t s js % jB{$IsI I R{s} I js RZ} h{$ R w]s}? ZjB 1D =t sR B$I {B8B ? y{s B I d, ; ,8 I sI$B k d(d1 , I 8sRs JZ t js tB% js et j B{? stB I js tB{Y >yt Y !{ st BP W$ Y d H I p B k tPB I s8 ts9s {Bt } {$}$ s R t 8$ sI I js ytI$s t j sK tB d t s ? s t RZ $8}s{ B Zts t ? s I ZtBR dx x(( 8 s Bt R 8Zk RZ} $B s jBR 1x( 8 s Bt R j$A sIBR t js $ ? st${s -}jBR$? Bt I j %Bj{? st s,s Bs t dMMn k
i {$ t 8 t R Ys RZ $IB JZ j { ? s t sIB t ]Y$-ZjZA t js } t? tRZjs I j OZ{s ? st w ? -${BD I ZtBR dM( ,$j? B8 BR I I$? s8 B }BI ? s {BtR $ Z$ j $R B P? BR$j I I${YB $ ? st${B $8}s{ B d et qY ] R 7BjZ $Bt >d MdH BA 7Ysb I R{ $A {? B8B j sR B$I ] R R ZRsIB }s s I R Z$ js NZts dM
© Los autores, 2001; © Edicions UPC, 2001.
x N k tIsR I Zt }jst s jjs8sIB q$ s
1x
3$ x dn 7$ 8} Ysk sj Z$ t t{s sIB I {Bt sI {$ jsR R sI? R ${sR JZ$%sj t s ZtsR 1( ((( AB8AsR s ? B8${sR {B8B js jst9sIs t <$ BRY$8s Vj ZtBR R ZI$BR Yst } 8$ $IB R $8s JZ j I$? s8 B I j { ? s } BIZ{$IB R } B}B {$Btsj s js s? 9 {? ZA${s I js t ? s j$A sIs t js {Bj$R$? Bt Ns {s? Is I Zt {Z }B {Bt jsR I$8 tR$Bt R I ? y{s B } BIZ{$ ? s Zt { ? s I ZtBR 11 ,8 I I$? s8 B JZ Ys ? s $ $RB $sR jsR I$8 tR$Bt R I j {BtB{$IB { ? s B B t V $9Bts _ R s JZ js } BAsA$j$IsI I {Bj$R$? Bt I Zt sR B$I B {B8 s {Bt js q$ s R js $%s8 t As`s Ys IsIB }$ sj ts{$8$ t B I Zt RZA ? t B I js {$ t{$s h{{$? Bt {s sR BhR s JZ j R{ $ B Ns k W$% t I tB8$ts $ TiB{,T<$ RTes YTWB% jR wWB% jsR I B{sR stI R JZ $8}s{ st {Bt js q$ sD {Bt tB sAj R } { I t R {B8B Ns R jjs >qY 7 s dM H I < p G jjR JZ I R{ $A jBR P { BR I %sR sIB R I j }sRB I Zt {Z }B st }B jsR } B-$8$IsI R I js q$ s Ns R? s $ s qY <B},$tR stZR{ $} >d n H I iBA ] 7Y $& ts s j I R{ZA $8$ t B I Zt 8stZR{ $ B I st st $ [ Z IsI JZ I R{ $A js {s? Is I js NZts RBA j B{? stB V j? st ${B {ZkBR P { BR R j$8$ st s js s}s ${$? Bt I sj ZtBR B tsIBR k RZts8$R Ns jZ{Ys }B jBR 8$t sj R } B{ I t R I js NZts {Zks }BR R$? Bt {BI${$st jBR Y I BR I js I RBjsIs q$ s }Bt I j$ % Zts % 9 8? sR jsR tR$Bt R JZ } Bj$P st t j I? s s I? s I js %$Is YZ8sts sR s I {$ JZ js {$ t{$s $tY t s I${Ys tB% js R %$I t 8 t tZjs FZt B s BA sR IBtI j 8s I js {Bj$R$? Bt R sAB Is B{sR$Btsj8 t {B8B t js {$ sIs et j B{? stB I js tB{Y I p B k tPB I {B -$R t { s{$Bt R }s ${Zjs 8 t tB sAj R {B8B V qB t BP 3s{ R >d E H I Fs8 R j$RY k WB 8st N t$ Y IBtI R I R{ $A js {Bj$R$? Bt t j sR B$I 3js%$s k js q$ s ej 8s $jjB I NZ{$P >NZ{$P :R <s88 d H tB% js I Ns k
WB8A {Bt j JZ R I R$ tst jBR 8s 8B BR B R ? R8BR } BIZ{$IBR t j PBtIB I j 8s JZ Ist jZ s s Bj s` R $ st R{BR
© Los autores, 2001; © Edicions UPC, 2001.
1xM
* $t Bt s e$tR $t
W$% t k F k _BZ t jj 7Y$%s * R{ tI$t >d M(H I p B k tPB I k G$jj$s8 iB Rj B jsR {$ t R ej 8s $jjB I *$BR I V YZ ] ]js , k ej j $RjsIB >d EH I j R{ $ B {s sj? st $JZ j I _sjBj qs8A$? t j {$t Ys -}jB sIB j hj? Bt I jsR {Bj$R$Bt R {? BR8${sR {Bt hj8 R {B8B qY ]B8 >d d(H { t sIB t j $8}s{ B I js q$ s {Bt j {? j A {B8 s <sjj k ej ht I j 8ZtIB >Ns ht IZ BtI d n(H JZ ts s jBR RPZ 9BR I IBR Y 8stBR }B Rsj%s js q$ s st js $t8$t t {Bj$R$? Bt I Zt {B8 s B VRsj B s js q$ s >={YZ`$t qB,kB t$ V sbs Z d xEH B s ,s$`Z $ s t js JZ ZtBR sj$ t? tsR }s {$IBR s R jjsR I 8s jj st s tZ R B 8ZtIB } B{ I t R I j }jst s _s$ s s } B}Bt j { R I } Z AsR tZ{j s R k s Zt$ RPZ 9BR }s s I R%$s Zt }jst s t Z8AB I {Bj$R$? Bt {Bt js q$ s et ej 8s $jjB I NZ{$P W$% t k _BZ t jj }sRst %$R s s jBR P { BR }B t{$sj R } B%B{sIBR }B js {s? Is I Zt {B8 s t js q$ s * s{Z IB {Bt jsR } B}B {$Bt R I 8s k $ s -$R t R t tZ R B }jst s uZt d0 I js RZ} h{$ R ? s {ZA$ s }B 8s R k B{? stBRu jBR sZ B R ZA${st js {s? Is RBA js RZ} h{$ I j 8s {$ {ZtR st{$s JZ B $ $ts BjsR $ st R{sR u RZts8$Ru JZ As t jsR {BR sR Ns t ? s j$A sIs t j $8}s{ B } BIZ{ js AZjj${$? Bt Bt I stI R 8sRsR I Zts st {st $IsI I s Zs wqsAjs x 1D {Bt js {BtR$ Z$ t PB 8s{$? tZABRsR k jjZ%$sR B t{$sj R eR B }BI ? s } B%B{s {B8B s}Zt s js tB% js j B tB s Zts tZ %s s js{$sj sj I$h{Zj s j }sRB I js sI$s{$? Bt RBjs et Zts j? t s 8Zk R$8$js 7Y$%s * R{ tI$t I p B k tPB I k G$jj$s8 iB Rj I R{ $A jBR I tBIsIBR RPZ 9BR I jBR BA$ tBR R R JZ I$R}Bt t I }B{B 8? sR I dd 8 R R }s s %$ s j t{Z t B j sj {Bt Zt t`s8A I sR B$I R t {ZkB { t B R$I 7Y$%s j t? Z{j B I Zt {B8 s I n( ((( 8$jjBt R I Bt jsIsR {Zks t ? s I $8}s{ B R ? s JZ$%sj t s ZtsR 1x( ((( AB8AsR I Y$I ? B tB VZ8 t B I js 8} s Z s I js s 8? BRP s VZ8 t B I js 8} s Z s I j s Zs I j 8s VZ8 t B I js 8} s Z s I j s Zs I j 8s YsR s jBR d(( 8 ]st $IsI I s Zs %s}B sIs sRs I $ s k { sIs k }Z R s t B ? A$ s W? Z8 B I 8B BR I 8s t$ ZI } BIZ{$IBR d ( 0 ] ( d 0 ] x 0] ; d(d , n d(dE , x d(x ,
qsAjs x 1 eP { BR JZ } BIZ{$ ? s Zt {B8 s I d(@N , t Zts {Bj$R$? Bt {Bt js q$ s s Zts % jB{$IsI I ;x ,8> R R$ BIs js t ? s j$A sIs t j $8}s{ B PZ s sARB A$Is wsIs} sIB I < ] = k d nD
qs8A$? t ej 8s $jjB I *$BR I V YZ ] ]js , }s I Zts Y$R B $s R$8$js s RZR } I { T RB sR sj$1d Zt sR B$I {Bt PB 8s I {s{sYZ I }B{B 8? sR I Zt ,$j? B8 B I jBt $ ZI k Zts 8sRs I 1 ((( 8$jjBt R I Bt jsIsR s%st9s R ? Zt Zts sk { B $s JZ $t -B sAj 8 t j jj %s ? s s {Bj$R$Bts {Bt js q$ s Ns tB% js JZ }B t{$s j I s8s $R8B I j t{Z t B YsR s j j? 8$ {Zj8$ts {Bt j R$ Z$ t - B sR js PB Z$ s P s 8 t s{$? Bt I sj$U " sj$ 1 t ? B t js s 8? BRP s }B{B st R I j s8st { {$ t ,$j? B8 BR }B t{$8s I <sbs$ Ns $ st R{s ABjs I PZ B } B%B{? B sj $tR st Zt PsjRB s8st { t j _s{? h{B I R} stIB s jBR st$8sj R Rsj%s` R ]Z $BRs8 t t js 8$ BjB ? s Y$tI? Z sj$ R j {BtRB I 7Y$%s 5 s {B$t{$I t{$s {Bt js tB% js I tPB I k iB Rj 2 1d
© Los autores, 2001; © Edicions UPC, 2001.
x N k tIsR I Zt }jst s jjs8sIB q$ s
N
I RZR 8$j k Zts $RjsR } B s }B{BR YZ8stBRU 8Zk }B{s t IB 8? s sJZ jjs tB{Y I tB{Y R Rsj%B sJZ jjBR JZ YsA? st AZR{sIB j Bj%$IB t jsR I B sR 7BA WZ %s jstIs j {sjB I j YB tB B A$ st $t{ tI$? B ABRJZ R k PZtI$? B js t$ % I jsR 8Bt sK tsR } B%B{stIB sjZI R t jBR %sjj R s RZR }$ R _B Zt sPB ZtsI? R$8B Bj} I RZ j } $t{$}sj $8}s{ B ? 8${B R } BIZ`B RBA js Vt ? s $Is j {Bt $t t JZ 8 `B }BI? s sARB A jB W$ R$JZ$ s sj$ }ZIB I RYs{ jBR ,$j? B8 BR I Y$ jB }Bjs } B sZt sR? j p st * RY$ jB {s8A$s ? s jsR {BR sR I BIB j }jst s W$t ? Zt RZ} %$%$ t PZ {s}s9 I I R{ $A$ j Z$IB I j }sRB I sj$ t$t Zts I jsR sAs{$Bt R PZ 8? sR JZ Zt I? A$j {B Ns {BA Z s I $8? s t R PZ RBA A$s }B RZ}Z R B k R ? s {Bt 8}jsIs {Bt 8B % t{$sj }B jsR t s{$Bt R % t$I sR _ B tsIs }ZIB {B8}s s R `s8? sR {Bt js R}st BRs sj$IsI *BR 8$tZ BR I R}Z? R I YsA } t sIB t js s 8? BRP s sj$ js sAstIBt? B }s s sI t s R I tZ %B t j R}s{$B 7Z s} B-$8s{$? Bt 8? s-$8s s js RZ} h{$ I js q$ s YsA? s R$IB I R R t s ,$j? B8 BR et RBR IBR 8$tZ BR R jj %? B {$ t 8$j %$IsR k {sZR? B IsK tBR }B %sjB I Zt A$jj? Bt I I? Bjs R" VZtJZ tB BIB j 8ZtIB R$ t }s%B st js }BR$Aj {s? Is I Zt {B8 s =ts %$R$? Bt {Z $BRs I j P t? B8 tB js A $tIs j 8s 8? s ${B P st{? R _$ N B sZ I sZ} Z$R wdE MTd x D JZ R{ $A? s t N RZ js {B8r >d x1HU "_B } j$ BRB JZ }Z Is RZj s j $8}s{ B I Zt {B8 s R ? s st j$ B $tR$ t$h{st JZ R? BjB } B%B{s ? s IsK tBR t js }s I tZ R B }jst s IBtI $8}s{ s s yt{jZRB tZ R s {BtR{$ t{$s }BI ? s I R{stRs t }s9 R$ s {s8A$B I js I %sR s{$? Bt I Zt $tB j R B I js q$ s }ZI$ s B9s I jsR {Z $BR$IsI R JZ sjA s s t RZ R tB Zt {Z }B { j R jj sIB I RI st j `BR +Z$9? sR tBR jj %s ? s8BR js tB 8 RB } Rs I {BtR s s JZ jBR R BR I R sR 8sRsR YsR s js P {Ys I R} {$sIsR R sAst {BtR $ Z$IsR }B B B k I$s8st R _ B 5JZ$? t JZ Is ? s 8? sR RB } tI$IB tBRB BR B jBR YsA$ st R I jBR {B8 sR jst9sIBR RBA tZ R B }jst s2 g]Z? st - sK tBR JZ tBR t{Bt s ? s8BR jBR ZtBR s jBR B BR " * Y {YB js s}Zt sIs }BR$A$j$IsI I RZ} %$% t{$s I Y$}B ? ${BR - s R R t Zt {YBJZ I sj R {s s{ ? R ${sR R {$ s8 t I$R{Z $Aj ]$ {ZtR st{$s JZ tB Ys $8} I$IB s sj ZtBR R{ $ B R k Z$Bt$R sR I j ? t B -}jB s R 8? BIB {B8B %? s }s s js $t%sR$? Bt I js q$ s }B }s I R R } B{ I t R I j R}s{$B VR? jsR ts% R 8s {$stsR I R{ $ sR }B G jjR t Ns Z s I jBR 8ZtIBR >qY Gs BP Y GB jIR dM MH R } {$}$ st RBA js RZ} h{$ R {B8B R$ R s s s I 8 BR 8 B $ BR jj stIB s B $ $ts $t{jZRB { ? s R I sj ZtBR 8 BR I } BPZtI$IsI qs8A$? t jBR hj8 R y ]s8 P B8 Y !Z 7}s{ yt%sR$Bt BP Y 7sZ{ t >d x H B yt%sRB R I s t B BR Z $j$9st R RZ $j {Z RB I $t%sR$? Bt 8Z{YB 8 tBR tB B $B JZ j {j? sR${B }js $jjB %Bjst 5_BI 8BR I$R K ts Zt R$R 8s B} s $%B I I {{$? Bt k I P tRs st js }B t{$sj {s? Is I Zt {B8 s B 8 B $ B2 ej _ Bk { B z$ $jst{$s eR}s{$sj JZ V YZ ] ]js , I R{ $A t js tB% js ej 8s $jjB I *$BR YsA? s R$IB ks 8 t{$BtsIB sj $t${$B I RZ 8Aj 8? s ${s tB% js ]$ s {Bt is8s >i tI 9%BZR b$ Y is8s d nH *${YB } Bk { B $ t js 8$R$? Bt I } % t$ js }BAjsIs q$ s I htsj R I j R$ jB y I jBR P { BR I js % t Zsj {s? Is I BA` BR } B{ I t R I j R}s{$B JZ sK tBR st R YsA? st } B%B{sIB js I R Z{{$? Bt I jsR {$ZIsI R I _sIZs k z Bts t jsR jjstZ sR I j tB I y sj$sU "* R}Z? R I j I R{Bt{$ B $t${$sj js YZ8st$IsI s{{$Bt? B {Bt Zts I 8$ts{$? Bt k Zts Zt$IsI JZ tB YsA ? s }BI$IB I 8BR s t t$t Zts ? }B{s st $B =t I RsR R 8 `st I RB R t? s }j ts {Bt{$ t{$s }BI? s tB %Bj% s RZ{ I t 8$j sK tBR } B }BI? s %Bj% s RZ{ I sj I? s R$ Z$ t O js } ? B-$8s % 9 jsR {BtR {Z t{$sR }BI ? st R
© Los autores, 2001; © Edicions UPC, 2001.
-
* $t Bt s e$tR $t
3$ x d; i } R t s{$? Bt RJZ 8? s ${s I js PB 8s t JZ }BI ? s Z $j$9s R js t ? s j$A sIs t Zts -}jBR$? Bt tZ{j s }s s $tIZ{$ Zts } Z As{$? Bt I j B I t I d {8> R t js % jB{$IsI I I R}js9s8$ t B I Zt sR B$I eR s } Z As{$? Bt R ? s RZh{$ t }s s 8BI$h{s RZ ? B A$ s k IZ{$ js } BAsA$j$IsI I $8}s{ B {Bt js q$ s ej $t t$B tZ{j s JZ t s } B Bt R k skBR s88s R I Bts s Zts I$R st{$s ? B} $8s I j sR B$I et js }B {$? Bt I js RZ} h{$ $ sI$sIs R B $ $ts Zts BtIs I {YBJZ JZ } B%B{s js P s 8 t s{$? Bt I j BA` B wsIs} sIB I q F VY tR k V G <s $R d nD BIs%? s } B R _Z R A$ tU tB YsA ? s Zts } ? B-$8s % 9 ]$ t sK tBR st R Zt 8ZtIB 8Z{YB 8? sR }BA {Bt {Z RBR 8Z{YB 8? sR I? A$j R YsA? s I$js}$IsIB RZR A$ t R t j $t t B I I R Z$ s 8sR jst9sIsR {Bt R}? $ Z RZ${$Is }B js YZ8st$IsI {Bt s jjs 8$R8s ej RPZ 9B $t${$sj tB Z%B ? -$ B } B jsR YsA$j$IsI R sIJZ$ $IsR tB R YsA? st Bj%$IsIB VYB s }BI? st R }Z R sR sj R %${$B I Zt BA` $%B 8? sR tBAj k Z $j$9sIsR s Zts R{sjs $tht$ s8 t 8? sR %sR s V t$t ? Zt 8 B $ B RZh{$ t 8 t stI {B8B }s s } B%B{s Zts {s ? sR BP tB R j %Bj% ? s s } 8$ $ JZ %$Bjs s jsR I P tRsR I js q$ s VR? {B8 t9? B j _ Bk { B z$ $jst{$s eR}s{$sj" B s R? BjB Ex( ((( ]Z $BRs8 t s s? 9 I j }sRB { {stB I j sR B$I d M 3] wJZ R s{ {? ,$j? B8 BR I js q$ sD j {B8$ ? RBA ]$ t{$s eR}s{$B k q {tBjB ? s I jBR eR sIBR =t$IBR RBj${$ ? B t d ( s js WV7V Zt } B s8s $t ts{$Btsj }s s js I {{$? Bt I BA` BR { {stBR s js q$ s *${YB } B s8s } R t sIB t d 1 PZ I tB8$tsIB } {$Rs8 t _ Bk { B I
z$ $jst{$s eR}s{$sj t YBtB s V YZ ] ]js , st ${$}sIB s js sj$IsI
=ts % 9 8? sR js h{{$? Bt }s { YsA R
et j hj8 B B > B d H j {YBJZ I Zt {B8 s {Bt Zt sR B$I } B%B{s JZ Zt P s 8 t B I M ,8 RZj $8}ZjRsIB t B ? A$ s I {Bj$R$? Bt {Bt js q$ s Ns Z ?t${s PB 8s I }s s sj 8 B B R $t { } s jB k I R Z$ jB Z $j$9stIB {Bt`Zt s8 t jBR 8$R$j R tZ{j s R tB s8 ${stBR k RB%$? ${BR $tR sjsIBR t R tIsR }js sPB 8sR B A$ sj R V } Rs I js tB sAj Bt I sRT I R{ $}{$? Bt I jBR sR} { BR sR Bt? B8${BR JZ s}s { t t j hj8 w{B8 sR {$t Z ? B$I R D j }BI I R Z{ $%B sR$ tsIB sj P s 8 t B 1!x(( 8 s Bt R RZj s I 8sR$sIB
© Los autores, 2001; © Edicions UPC, 2001.
x N k tIsR I Zt }jst s jjs8sIB q$ s
-@
3$ x dx ]s j }ZAj${$ s $B I j hj8 B B > B d H IBtI R 8Z R st jBR P { BR I %sR sIB R I j $8}s{ B I Zt sR B$I RBA js {$ZIsI I WZ %s OB ,
© Los autores, 2001; © Edicions UPC, 2001.
-
* $t Bt s e$tR $t
} JZ K tB R$ R {B8}s s {Bt jBR P { BR JZ R R} s JZ } B%BJZ Ns }BR$A$j$IsI }jst sIs t j hj8 I B Z s I Zt sR B$I B 8 B B }B $8}s{ B I 8$R$j R tZ{j s R PB 8s }s I Zts R $ I R s $sR $I sIsR }s s jZ{Ys {Bt s BA` BR JZ R s{ {st I 8sR$sIB s js q$ s _ R s JZ jBR 8? BIBR {Bt{ A$IBR RBt s{ Zsj8 t Ps{ $Aj R tB }s { t t { Rs $BR I 8B8 t B IsIs js R{sRs } BAsA$j$IsI JZ sj R {Bj$R$Bt R R } BIZ9{st wg{ Z{ 8BR jBR I IBR D * Y {YB j $8}s{ B I$ { B I Zt } Bk { $j I Zt { t ts I ,$jB s8BR 8B%$? tIBR s Zts s RZh{$ t }s s I R%$s j sR B$I I Zts }BR$Aj {Bj$T % jB{$IsI js $%s I ZtBR d1 ,8> R R ? R$? Bt {Bt js q$ s {ZstIB j s8sK tB I ? R PZ s $tP $B s jBR d(( 8 Ns $ sI$s{$? Bt I js RZ} h{$ I j sR B$I }B -}jBR$? Bt I Zt 8$R$j tZ{j s t RZR $t8 I$s{$Bt R R j 8 {st$R8B 8? sR P { $%B }s s BA` BR I I$8 tR$Bt R 8skB R t d k d( ,8 w3$ x d;D 7$ 8} {js B R ? s JZ R st I { sIBR s $ 8}B _ j? {ZjsR {B8B * } y8}s{ >d MH B V 8s IIBt >d MH {BtR $ Zk t s} B-$8s{$Bt R {$ t R s R s s8 ts9s js t WB% jsR {B8B ej 8s $jjB I *$BR $jZR st I PB 8s tB sAj sj ZtBR I jBR } B{ I$8$ t BR RZ $IBR }s s Ys{ P t s Zt {B8 s B sR B$I t Z8AB I {Bj$R$? Bt {Bt js q$ s _s s %$ s js }BR$Aj B Z s I j R$t$ R B sj$ k js Zj $B jjZ%$s I P s 8 t BR RBA js RZ} h{$ I j }jst s jBR BA$ tBR R R B} st t } $8 s $tR st{$s }B ZA${s Zt 8B B T{BY {Bt Zts {s s I 1(( ((( Bt jsIsR I Y$I ? B tB j? JZ$IB RBA js } B}$s RZ} h{$ I j sR B$I ej t{ tI$IB I j 8B B I A ? s sj `s } B R$%s8 t s sj$ I RZ BA` $%B 7$t 8As B t js tB% js j RsAB s` I ZtBR Pst? s ${BR j$ $BRBR } B%B{s js }? I$Is $ }s sAj I j {B8AZR $Aj k sj$ } BR$ Z RZ Z8AB j sj et Zt tZ %B }ZjRB {Bt sj$ js q$ s I {$I jst9s Zt 8$R$j tZ{j s I d ((( 8 s Bt R }s s R{$tI$ jB t IBR 8$ sI R WZ %B $t t B Psjj$IBU $9stIB j st${B JZ $9B js tB% js s}Zt s JZ sj $8}s{ s {Bt j sR B$I s d(( ,8\R j } {Z B 8 {? s{{$Bts j $t t$B tZ{j s tB RZj s B} s $%BU js AB8As tB -}jB s 7$t 8As B s{$sR s RZ j %sIs t ? s {$t? ${s j 8$R$j {BtR$ Z $t R} sIs8 t RZ } B}? BR$ B I P s 8 t s sj$ et et j B{? stB I js tB{Y I p B k tPB I j 8? BIB Z $j$9sIB }s s I R Z$ j $tJZ$ st sR B$I ? y{s B {BtR$R t js I Bts{$? Bt I Zt 8$R$j JZ j $t ? }$IB sR BtsZ s W$ j Gsj8Rj k ZA${s } RBtsj8 t t js RZ} h{$ I I${YB sR B $ Zjs VZtJZ js q$ s R$ 8} }Z I B} s }B Zt {Z RB sj ts $%B {B8B j RZ $IB }B j } BP RB 3jB R st } B s Bt$R s I js tB% js ej j $RjsIB I $JZ j I _sjBjU st j $t8$t t $8}s{ B {Bt j {B8 s 3 s9 jjsTp [ BR }jst s js %s{Zs{$? Bt I j }jst s s AB IB I Zts $ st R{s ts% R}s{$sj IBtI jBR Y I BR I js YZ8st$IsI s Zs Is ? st j {Z RB I jBR s{Bt {$8$ t BR VZtJZ JZ$9? sR j 8 I$B R s } B JZ js tP 8 IsI z$Is k - $t{$? Bt RBt IBR I R $tBR st - 8BR }s s Zt R YZ8stB JZ JZ$? t R s ? s {BtPB 8 RBA js RZ} h{$ I j }jst s s{sRB {BtPB sIB }B j 8 B Y {YB I js } R$R t{$s I js YZ8st$IsI 5O JZ? { $ $BR I R j {{$? Bt I A ? st s}j${s R st js $8}BR$A$j$IsI I {BtR Z$ Zts ts% }s s sjA s s E ((( 8$jjBt R I YsA$ st R2 WB R? BjB Zts {Bj$R$? Bt P { $%s {B8}B s {BtR {Z t{$sR {s sR ? Bh{sR ej } B}$B }sRB I Zt BA` B
VZtJZ R$ 8} JZ Is ? s j {Z RB I s}s s js q$ s I js sk { B $s I $8}s{ B {B8B RZ $ t jBR $t tZBR Z$Bt$R sR I j hj8 pB s Y >d E1H Os }Z R BR jBR P { BR B{sR$BtsIBR }B j I R}js9s8$ t B I js q$ s I R}$ st {B8B R tB 8s t BIB hj8 `s}Bt? R s Zt 8BtR ZB } Y$R ? B ${B
© Los autores, 2001; © Edicions UPC, 2001.
x N k tIsR I Zt }jst s jjs8sIB q$ s
1En
8sR$%B }B jsR $t8 I$s{$Bt R I js q$ s }Z I } B%B{s s} {$sAj R } Z As{$Bt R s%$ sT B $sRU jsR PZ 9sR I 8s s VR? t j hj8 ]ZstIB jBR 8ZtIBR {YB{st >GY t GB jIR ]Bjj$I d xdH AsRsIB t js tB% js YB8? Bt$8s I eIb$t sj8 k _Y$j$} Gkj$ >d nnH Zt } JZ K tB R$R 8s }jst s $B {BtR $ Z$IB }B jjZR Zts R jjs st k k s Zt 8ZtIB }s {$IB s js q$ s s%st9s t sk { B $s I {Bj$R$? Bt {Bt tZ R B }jst s et B{YB 8 R R js } B-$8$IsI I k s } BIZ{$ ? s 8s sR I {BtR {Z t{$sR $t{sj{ZjsAj R 7? BjB I$ {$tZ % I? sR I R}Z? R Zt $8}s{ B P Bt sj {Bt jjZR I R Z$ ? s js q$ s Vt js t s $%s I jsR Ws{$Bt R =t$IsR s js {BtR Z{{$? Bt I $t t$BR R}s{$sj R }s s %$ s js I R Z{{$? Bt 8sR$%s j * < tI Bt w t Zt }jst s8$ t B R$8$js sj I RZ {Bj s j } BP RB 3jB R st I js tB% js ej j $RjsIB D I {$I {BtR Z$ Zts R} {$ I s {s R}s{$sj {Bt BA` B I t%$s sj ZtBR YZ8stBR s k s k %$ s js - $t{$? Bt I js R} {$ eP { $%s8 t j }sRB I jjZR I R Zk js q$ s k jBR RZ} %$%$ t R $t${$st Zts tZ %s %$Is t k s s IBtI s $As js ts% I j * < tI Bt Zt }jst s I s 8? BRP s R}$ sAj {Bt t$ % k % s{$? Bt et js } j? {Zjs R sh 8s JZ j R$R 8s jjZRu k s R Ys I R}js9sIB d E 8$jjBt R I ,$j? B8 BR t R? BjB IBR R 8stsR _B {Bt s t B B $tR st I j hj8 R I${ JZ t 8 tBR I Zt sK tB {B ? s jBR ; M(( 8$jjBt R I ,$j? B8 BR JZ jB R }s s I js q$ s V tI$ tIB s js } $8 s R $8s{$? Bt js jj sIs s js q$ s R I 8B s ? s -s{ s8 t E ((( Zt 8B B {$ B }s s Zjs R 8stsR R I {$ gddx sK tBR w$ tB s8BR R$ j R$R 8s I$R}Bt I sj ? RZ % jB{$IsID _B B B jsIB k s } R t s } RZ8$Aj 8 t Zts 8sRs {B8}s sAj s js I js q$ s sj }BR I$8 tR$Bt R R$8$js R NBR P { BR } BIZ{$IBR 8B BR k BjsR $ st R{sR R? BjB R ? st }s {$IBR s jBR I R{ $ BR t j hj8 {ZstIB j }jst s R t{Bt s s s Zts I$R st{$s {B8}s sAj s js B ? A$ s I js NZts t {Zks {sRB sI 8? sR } BIZ{$ ? s stI R } Z As{$Bt R t RZ B ? A$ s sR} { B tB {Bt 8}jsIB t j hj8 7$ t 8BR t {Z t s JZ js NZts R js %$ Zsj R}BtRsAj I jsR 8s sR R R k JZ ? R s }BR Zts 8sRs Md % { R $tP $B s js R R I R} s JZ jsR 8s sR {sZRsIsR }B Zt sR B {B8B k s R$ ZsIB s js 8$R8s I$R st{$s tI ? st Zts 8s t$ ZI Md % { R 8skB Ns R jjs jjZR }B {Bt s R I R{ $A t js } j? {Zjs {B8B Zts R jjs $ st sZtJZ {Bt Zt s8sK tB I$ 9 % { R $tP $B sj I j 7Bj I$P? {$j8 t R s s ? s I Zts $ st 7$ RZ}Bt 8BR JZ js 8sRs I jjZR R } B}B {$Btsj s RZ %BjZ8 t k }B {BtR$ Z$ t sj {ZAB I RZ sI$B }BI 8BR R $8s RZ 8sRs t ZtsR 1x ((( % { R js 8sRs I js q$ s {B8}s sAj s js I Zt }jst s $ st {B8B F? Z}$ k j$ s8 t $tP $B s js 8sRs 8? t$8s I Zts R jjs t { Rs $s }s s $t${$s jBR } B{ RBR tZ{j s R t RZ $t $B JZ j } 8$ t A $jjs t js tB{Y I jBR $ 8}BR , ! ! !
=ts R jjs B Zt }jst s tB R 8s $sj$9st t j R$R 8s RBjs I } t 7Z } R t{$s R ? s I { sIs 8Z{YB $ 8}B st R I RZ jj sIs P { $%s 7? BjB Zt Y$}B ? ${B }jst s st {B8B j {Bt{ A$IB }B 3 $ 9 N $A t RZ js B ej %s sAZtIB >qY GstI d E;H JZ 8 R? ZA$ s8 t I Zt tB 8 tBR $8} BAsAj Y$} R}s{$B } B%B{stIB js I R Z{{$? Bt I js q$ s }BI ? s jZI$ BIs I {{$? Bt ! s -{ }{$? Bt }BR$Aj R js I sJZ jjBR {Z }BR I } JZ K tB s8sK tB B As`s jZ8$tBR$IsI {Zks I {{$? Bt } R t s ? s } BAj 8sR V R R} { B I R s{s js {Z $BRs R? s $ s I yRss{ VR$8B% V{ {s I tsIs >VABZ WB Y$t d HU t j sK tB 1d1x j } BP RB F B8 <$ Btk8ZR I { s Zt s Z` B t B t Z8AB I {Bj$R$? Bt {Bt js q$ s ]ZstIB BIB j 8ZtIB R$ tsIB Ys B} sIB ks }B I R} I$ R I RZR sjj sIBR <$ Btk8ZR sh 8s JZ t % IsI tB R s s I Zt s Z` B t B R$tB I Zt sR B$I JZ sj Z$ t Ys }$t sIB I t B e-$R t B sR PZ t R }B t{$sj R I {s ? sR BP R R R {B8B js -}jBR$? Bt I R jjsR } ? B-$T
© Los autores, 2001; © Edicions UPC, 2001.
1E;
* $t Bt s e$tR $t
8sR t PsR R 8$tsj R I RZ %BjZ{$? Bt VR? yst Gs RBt t qY iB t t i PZ R >d ;H I R{ $A js -}jBR$? Bt I RZ} tB%s I js R jjs 7$ $B R$ ZsIs s ZtBR sK tBR jZ9 I I$R st{$s Ns {BjBRsj sI$s{$? Bt 8$ $Is I R Zk BIB R$ tB I %$Is t js q$ s -{ } B js JZ R t{Z t s } B $Is t j $t $B I PZ $BR } BPZtIBR ! s -}jBR$? Bt I RZ} tB%s s dx( sK tBR jZ9 I js q$ s $8s $tsIs } i${Ys I ]Bb} t RZ js B qY qb$j$ Y BP $s ZR >d ;H } B%B{s s8A$? t sj s{$Bt R $8}B st R t j {j$8s R JZ {BtIZ{ t s Zts tZ %s s js{$sj ej P t? ${B $t t B I RZ} %$% t{$s I Zts YZ8st$IsI s{BRsIs }B jBR I %sR sIB R P { BR I Zts $t tR? R$8s sI$s{$? Bt {? BR8${s R ts sIB t BIs RZ { ZI 9s t yth tB >qY ytP tBH I 3 I k p B& k <Bkj U js sI$s{$? Bt {? BR8${s 8 I$Is t js q$ s {ZkB B $ t R js{$Bts $t${$sj8 t {Bt js -}jBR$? Bt I Zts RZ} tB%s t j { t B sj? s{ ${B s}B s R$ tBR $t JZ? %B{BR I Zts {s ? sR BP s? Zt 8? sR {BjBRsjU tZ R s psjs-$s js z? s N? s{ s R {Bt%$ t Zts %$Bj t s sjs-$s 7 kP Zts I jsR jjs8sIsR sjs-$sR s{ $%sR ej -{ RB j sj I sI$s{$? Bt JZ $tZtIs j jBAB BAj$ s s jBR sPB ZtsIBR RZ} %$%$ t R s AZR{s PZ $B Zts % 9 8? sR t RZA ? st BR k {Z %sR Ns 8} s Z s B9s jBR j? 8$ R Bj sIBR }B js %$Is ej Y 8$RP $B sZR sj tPB{sIB Ys{$s js }BR${$? Bt JZ B{Z}s j { t B sj? s{ ${B R {Bt%$ t Zt $th tB $tP R sIB I 8B ? P s sI$s{$? Bt k {BjBRsj R $t{ tI$BR $ t sR jsR I$P t{$sR I 8} s Z s {Bt j Y 8$RP $B AB sj R$ 8A st js q$ s I %$Bj t BR YZ s{st R NsR t s $%sR I RZ} %$% t{$s I js YZ8st$IsI I A t Ys{ P t s Zt tZ %B %? RU 8$ t sR Zts 8$R $BRs t $IsI - s R $t t s Rsj%s Zs Is js %$Is t js I$ 98sIs q$ s ` {$ tIB I R{ZIB st js sI$s{$? Bt j A ZR{B I R{ tRB I jsR 8} s Z sR stRPB 8st j {sjB t Zt P ? B js{$sj y Zsj8 t 8B ? P s R 8Z R s js $t R} sIs $t%sR$? Bt I RP sR ? t sR sZ B s%$ st R I js tB% js Bjs I PZ B >3$ Asjj d M H I j P? R${B k I$%Zj sIB A $ ? st${B _sZj *s%$ R ej s Z8 t B R AsRs t jsR {Bt B% $IsR BAR %s{$Bt R I skBR t ABjs tB } BIZ{$IBR t jsAB s B $B k s {ZkB R ZI$B R Yst I I${sIB P? R${BR I js sjjs I W${Bjs q Rjs B _$B s}$ Rs ej } B}$B WBA j I JZ? 8${s G 3 N$AAk s $AZk? B t d Ex js I %sR s{$? Bt I js qZt ZR,s R$A $sts s js {s? Is I Zts ABjs I PZ B {B8B jsR JZ t js tB% js s sRst B8Ask Ns I R Z{{$? Bt I Zt $tJZ$ st s Ps{ B sj$ t? ts k js {BtR$ Z$ t j$A s{$? Bt I {$ s {st $IsI I st $8s $s {BtR $ Zk t js $tRBR} {YsIs PZ t I sj R $ ? st${sR -}jBR$Bt R RZj sIB I j {Bt s{ B {Bt 8s $s {Bt% t{$Btsj Ns sj s{$? Bt I jBR } B{ RBR P? R${BR JZ BA$ tst j $t $B I j 7Bj {BtR $ Zk B s PZ t {s}$ sj I {s s{j$R8BR t tZ R B } JZ K tB 8ZtIB s9Zj et j 7Bj >yt B Y 7Zt dMM1H I iBA *Zt{st $jt ts s js PB Z$ s {s? Is I Zt {B8 s JZ R } {$}$ s {Bt s js RZ} h{$ I tZ R B 7Bj ej I R8 RZ sIB sZ8 t B I js 8} s Z s RBjs R sIZ{ t Zt R? ZA$ B $t{ 8 t B I {sjB Zt s$ RBPB{st k sRh-$st k 8$j R I 8Z BR }B $tRBjs{$? Bt _ Bt B jsR {$ZIsI R R stRPB 8st t Zts I Rh Z sIs $8s t I 8Z k I R Z{{$? Bt 7$t 8As B js 8sRs I Zt {B8 s R $tRZh{$ t }s s sj s RZR st{$sj8 t j {B8}B s8$ t B I Zt {Z }B {B8B j 7Bj * Y {YB sj ZtsR RBtIsR R}s{$sj R I R $tsIsR s RZ R ZI$B {B8B j Rs ? j$ 7!<! Yst BAR %sIB } $Is8 t js $t -B sAj {s? Is sj 7Bj I sj ZtBR {B8 sR JZ %$R$ st j R$R 8s RBjs et st B js %$Is t js q$ s R$ Z RZ {Z RB qs8A$? t js ? Bt s stRPB 8s{$? Bt I j 7Bj t Zts tB%s n sR Zts R $ I $t R sA$j$IsI R I 1n
=ts tB%s R Zts -}jBR$? Bt 8BtZ{j s JZ $ t jZ s t js RZ} h{$ I Zts R jjs I Zt
© Los autores, 2001; © Edicions UPC, 2001.
x N k tIsR I Zt }jst s jjs8sIB q$ s
-N
B $ t tZ{j s Ys } B%B{sIB j ? -BIB I js YZ8st$IsI k js - $t{$? Bt I BIB % R $ $B I %$Is RBA tZ R B }jst s t I$% RBR js BR k tB% jsR I j ? t B {B8B _s $Is I R{s >i R{Z _s k d ;EH B ]? st ${BR I js j `sts q$ s >7Bt R BP *$R st es Y d MEH s8AsR I V YZ ] ]js , B js R $ I j N$A B I j 7Bj tZ %B I p t GBjP $t${$sIs {Bt Ns RB8A s I j B Z sIB >qY 7YsIBb BP Y qB Z d M(H ! B $}B I {s ? sR BP R $8s $tsIsR t js {$ t{$s h{{$? Bt Zs Is js{$? Bt {Bt I 8$tsIBR $t t BR }B 8BI$h{s jBR j 8 t BR B A$ sj R I js q$ s VR? t qY *sk Y es Y ]sZ Y 3$ >d E1H js I Bts{$? Bt R$8Zj ? st s I IBR AB8AsR I Y$I ? B tB }B }s I tB s8 ${stBR w t js Vt ? s $IsD k RB%$? ${BR w t 7$A $sD } B%B{s Zts sj s{$? Bt t js B ? A$ s R JZ js $8}ZjRs t Z8AB I {Bj$R$? Bt {Bt j 7Bj _s s I R%$s js q$ s t Zts I 8$tsIs I$ {{$? Bt R I A ? s } B}ZjRs Zts tB sAj {st $IsI I 8s $s t R t $IB B}Z R B k s Zts % jB{$IsI ZjB 1D 7Z}Bt$ tIB JZ js -}jBR$? Bt I Zts AB8As I Y$I ? B tB 8skB s js I R{s} w]s}? I EM 8 s Bt R wR$8$js sj $t t$B tZ{j s 8? sR }B t I BtsIB `s8? sR t js q$ sD -}ZjRs d(M Bt jsIsR I 8s $sj s js % jB{$IsI I R{s} R js q$ s R % ? s $8}ZjRsIs t R t $IB B}Z R B {Bt Zts % jB{$IsI $I? {Zjs d( d( ,8> Y * Y {YB {s s{j$R8BR ts Z sj R 8Z{YB 8? sR I %sR sIB R {B8B js -}jBR$? Bt I j %Bj{? st s,s Bs wdMMnD B js I js $Rjs $ s I qY s wdxx( s ] D tB Yst } BIZ{$IB {s8A$BR s} {$sAj R t j ` I B s{$? Bt t$ t js B ? A$ s R qs8}B{B $ t t ? -$ B jBR RPZ 9BR I jBR 8$ 8A BR I j pZtT]jZA }B 8BI$h{s j ` I B s{$? Bt I js q$ s s} B% {YstIB j B{ RB I Zt 8BtZ8 t sj {sK tB ?t $tR sjsIB t Zts 9Bts I j {ZsIB sj k {B8B I R{ $A z t t RZ tB% js ej R { B I sR Bt>7stR I RRZR I RRBZR dMM H =t B I {? sj{ZjB jj %s sj P s{sRB I j } Bk { BU j ` R tB R I R}js9s 8? sR I n 8$j? R$8sR I 8$j? 8 B eP { BR 8Z{YB 8? sR 8B ? P BR }BI ? st } BIZ{$ R R$ jBR } tRs8$ t BR $8s $tsIBR }B j } BT s Bt$R s I ej YB8A JZ }BI? s Ys{ 8$js BR >qY st GYB <sI B 7$t dM MH I < s Ys{ 8$js BR >qY st GYB ]BZjI p G jjR wsIs} sIs sj {$t {B8B ej YB8A JZ }BI? GB , $ s{j R d nEHD R 8s $sj$9s st {B8B t js h{{$? BtU sR I R{ZA $ s{{$I t sj8 t RZ 8$R $BRB IBt }s s ` {Z s 8$js BR p B {GY$ 3B Y $t sk R$ t j $8}ZjRB I Z $j$9s RZR }BI R t A t h{$B I js YZ8st$IsI y tB stIB j } j$ B }B t{$sj I RZR s{ BR I {$I }s s js q$ s NBR P { BR {B8B I R{ $A js tB% js R ? st tZ$ts8 t I %sR sIB RU BIB {Z }B JZ tB R Z%$ s P? s8 t RZ` B s Zts R Z{ Z s RsjI ? s I R} I$IB s st % jB{$IsI YsR s $8}s{ s t Zts {Bj$R$? Bt } BAsAj 8 t 8B sj {Bt s j 8? sR $tRBR} {YsIB I$h{$B % Y? {ZjB Z BA` B 7BA jBR }BjBR I js q$ s IBtI j P { B { t ? PZ B R tZjB j P t? B8 tB }sRs ? s {sR$ I Rs} {$A$IB } B {ZsjJZ$ BA` B ZA${sIB t j {ZsIB R R s } tRs t sP s R s Zt % ? s $8}ZjRsIB s d EM( ,8\Y et R sR {$ {ZtR st{$sR ZtB }BI ? {js%B s I$ tIB O tZt{s 8 `B I${YBU js j$A s{$? Bt I js t ? s I B s{$? Bt R sj I t RZ 8B%$8$ t B } BIZ{$ ? s Zt {sj t s8$ t B jBAsj JZ R$ Zs ? s s 8s R k B{? stBR sj AB I I RZ }Zt B I AZjj${$? Bt ej {s8A$B {j$8? s ${B htsj R ? s I ht$ $%B }s s js %$Is t js q$ s _B RZ tB BIBR jBR RZ K tBR R {Bt%$ t t sj$IsI
R$R 8s A$ts $B =ts R jjs s$RjsIs {B8B j 7Bj tZt{s }BI ? s Is jZ s s Zts -}jBR$? Bt I tB%s
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
1E
E
pZ? s }s s %$s` BR I j $ 8}B
7BA sAZ jBR } R Z$IBR }B jBR {B IB R I j $ 8}B { BtBR ? R8BR k B sR }s sIB`sR 8}B sj R 7BA Y$} R}s{$BR s Z` BR I ZRstB k t? sZP s BR s js I $%s t j } B{ jBRB 8s I j $ 8}B
ugV`? s u -{js8? B j t$ t 7stI RBt e s j 8 `B gV`? s JZ YsA? s B? IB YsR s t Bt{ R uNs 4Z$I 9 I j }sRsIB s8$ B 8? B R Zts RT }sIs I IBAj hjB 7$ j }sRsIB }Z I R {s8A$sIB Zts % 9 }Z I R jB %s $sR % { R VYB s jj s8BR sj }s} j I js _s Zjjs q 8}BT sj ]BtR$I 8BR j {sRB I j I R JZ$j$A sIB JZ sR R$t? B s F R? ZR {ZstIB s Zt t$K tB * A$IB s st $Aj s{ B js ] $R $stIsI tB s}s {$? B k Zts st }s I j y8} $B iB8stB 8$t? B }B {Bt% T $ R sj `ZIs? R8B NBR I$ $ t R `ZI? BR I iB8s PZ Bt {s}s{ R I %$ s js {s? Is I j y8} $B I jBR R$ jBR yz k z jB stIB Zt R sIB B{ ? s ${B k 8BtBj? ${B JZ {Bt Bj? B BIs eZ B}s B{{$I t sj VR? j y8} $B $9st $tB tB R I Rs Bjj? B t B $ t JZ PZ IB8$tsIB I RI F ZRsj? t }B Zts R { s Y A s${s {$R8? s ${s et j R$ jB Zts Z s {s s{j? R8${s t jsR PZ 9sR I iB8s k F ZRsj? t } B%B{? B js I R Z{{$? Bt I js {$%$j$9s{$? Bt k js $t%sR$? Bt I BIs eZ B}s k VR$s }B jBR t? B8sIsR Z {BR JZ R I I${s Bt s js {BtR Z{{$? Bt I Zt R sIB B sj$ s $B JZ Y$9B JZ j R$ jB y PZ R j 8? sR R$%B I BIs js Y$R B $s YZ8sts _Z I t % jB I %sR sIB s JZ RZj s js 8 tB $t` t{$s t j }sRsIB
iBA 7$j% A _B j $ 8}B >=} Y N$t d E H
wy9JZ$ IsD =t jBAB {Bt }$ j I {B I BU j {kAB qTM(( % IsI B `$IB YZ8stB RBA tIB RJZ j B I 8 sj * js } j? {Zjs q 8$ts B 1U j `Z${$B htsj >q 8$ts B 1U FZI 8 t *sk d dH
© Los autores, 2001; © Edicions UPC, 2001.
1EM
* $t Bt s e$tR $t
=ts ts% st RZ {s j R}s{$B $tht$ B Z8AB sj { }jst s I Zt 8B B R$R 8s RBjs Zt 8ZtIB s9Zj jjs8sIB q$ s *Z st j %$s` j } JZ K tB sjTej Y$`B I Zt {$ t ? h{B I $} Bt R sj {{$BtsIB }B jsR sAs{$Bt R JZ j j s RZ }sI t jsR {BR Z8A R k Y? sA$ BR I jBR YZ8stBR V RZ jj sIs s Rs $ s } B8 $Is sR Zt } $}jB s s%? R I E sjs-$sR sjTej Ys t% ` {$IB n sK tBRU j `B% t 7Z} 8st R R? BjB Zt t$K tB YZ? PstB sZtJZ IB sIB I }BI R sRB8A BRBR JZ } Bt B ZRs ? s t I P tRs I RZ 8ZtIB sIB} $%B Ns q$ s I A }BR sR BR 8Zk R} {$sj R }s s JZ Zt {$ t ? h{B I $} Bt Zt I$R st }jst s t jBR {Btht R I j {BR8BR I {$Is R{B js {B8B {Zts }s s RZ } $8B ? t$ B _BI ? s8BR } tRs JZ FB Tej j }sI I 7Z} 8st s Zt % IsI B t ZR$sR s I jsR s R I jsR {$ t{$sR k I jsR R sR sj{st9sIsR }B jBR R R YZ8stBR WB t %stB IZ st j %$s` I j } JZ K tB sjT ej j $t BIZ{ {Bt B ZjjB t j R$tZBRB 8ZtIB I js P? R${s R N YsAjs I e$tR $t k I RZ {? j A B ? s I js js $%$IsI wg st Ps8BRs JZ RZR jB BR RBt {BtB{$IBR $t{jZRB s E sjs-$sR I I$R st{$s D 7$t 8As B } R s RZ }s t ZI${$? Bt FB Tej }s { YsA $ tB sIB sj Zts I jsR $tJZ$ st R $8}j${s{$Bt R I RZ A$ ts8sIs B ? s I js js $%$IsIU }s s {B E sjs-$sR t R? BjB n sK tBR 7Z} 8st I A$? B }s $ I $} Bt Ys{ g8? sR I d( 8$jjBt R I sK tBR Ns q$ s s t Bt{ R Zt 8ZtIB $tY? BR}$ B et RZ RZ} h{$ BIs%? s R jjB sAs js - $t{$? Bt I jBR I$tBRsZ $BR k s{sRB js R} {$ 8? sR $t j$ t j 8BtB } BR Z? s RZ js s {sI ts %BjZ $%s JZ I R 8AB{s ? s 8$jjBt R I sK tBR 8? sR s I t jBR } $8 BR YZ8stBR 5e s t { Rs $B s s% Rs E sjs-$sR }s s t%$s s sjTej s Zt 8ZtIB }BAjsIB }B R$8$BR2 5+Z? }sI {B ? s R $ R B {Bt Zt Y$`B2 +Z$9? sR Ysks8BR RZA R $8stIB js {$ t{$s I $} Bt k RZ }BI I } I${{$? Bt _ B 5}Z I st ${$}s R j PZ Z B {Bt sj } {$R$? Bt2 * A ? s8BR I R{ZA $ tBR st FB Tej Zt % IsI B %$R$Bts $B {s}s9 I YsAjs s RZ Y$`B I js B ? s I js js $%$IsI k I Zt sj e$tR $t g{ZkB ts{$8$ t B R I 8B s ? s s? Zt d( 8$jjBt R I sK tBR E d _ ? B-$8s R s{$? BtU R$ jB ]B R}BtI t{$s {Bt B sR j? t sR I j $ 8}B
NBR stI R ? B}${BR I js {$ t{$s h{{$? Bt Yst {BtR $ Z$IB Zt {js B 4 `B I jBR RZ K tBR st{ R sj R I js YZ8st$IsI et {s}? ZjBR st $B R Y 8BR %$R B {? B8B 3 st, tR $t 8s $sj$9sAs j RZ K tB I js $t8B sj$IsI k {B BtsAs jsR stR$sR I {BtB{$8$ t B I j R YZ8stB RZ }s} j I { sIB JZ jB JZ$}s s s js h Z s I *$BR ytRBtIsAj R $8} $BR sj? s{ ${BR k P I s{$Bt R }jst s $sR Yst Rs{$sIB j sP? st I {BtJZ$R s JZ {s s{ $9s s tZ R s $tI? B8$ s R} {$ Ns - tRs sj ? s I RZ} Y? B R w$t{jZRB j } B}$B YB8A $t%$R$Aj D tBR Ys } 8$ $IB RZ} s $8s $ts $s8 t jsR j$8$ s{$Bt R I j {Z }B YZ8stBU { $s Z sR 8? sR s ? $j R 8? sR ? s}$IsR 8? sR PZ R Z{YBR I R BR RZ K tBR Yst RZ{Z8A$IB sj $t -B sAj s%st{ I js {$ t{$s k I j {BtB{$8$ t B Ns {$ t{$s tB R? BjB Ys %BjZ{$BtsIB js PB 8s I R{ $A$ {$ t{$s h{{$? Bt j stIB js 8s $s sj ? t B I js Pst sR? s ]BtR $ Zk s8A$? t Zt 4 `B I RZ s%st{ *? s s I? s jsR tB% jsR I {$ t{$s h{{$? Bt $t{B }B st tZ %BR sR} { BR {$ t ? h{BRU sR? js j { ${$IsI k j 8s t $R8B }s sI$ 8sR I js {$ t{$s I j R$ jB y Yst }sRsIB j j %B s jsR RB } tI t R $8}j${s{$Bt R I js P? R${s 8BI ts I RI js js $%$IsI s js P? R${s {Z? st ${s JZ RBt s{ Zsj8 t -}jB sIsR t 8Z{YsR tB% jsR k } j? {ZjsR I j ? t B
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
-
_ B tB R? BjB js {$ t{$s h{{$? Bt R tZ I jBR s%st{ R I js {$ t{$s < 8BR sR$R $IB s8A$? t s Zts P Z{ ? P s R$8A$BR$R t {$ t{$s k {$ t{$s h{{$? Bt _B Zt jsIB I R s{sIBR {$ t ? h{BR {BtB{ t YsA I R{ZA$ B RZ %B{s{$? Bt }B js {$ t{$s R $8ZjsIBR }B js BR I {$ t{$s h{{$? Bt 7Y jIBt N pjsRYBb jsZ sIB {Bt j WBA j I P? R${s t d R{ $A? s t RZ j$A B ej t{st B I js P? R${s >qY ]Ys 8 BP _YkR${R d dHU "ej 8s $sj JZ R }ZAj${sAs t js %$R s VR BZtI$t 7{$ t{ 3${ $Bt 8 $t${$? B t js js $%$IsI k js B ? s {Z? st ${s" qs8A$? t Z sk p jjT stt }sI I js B ? s I jBR JZs ,R k } 8$B WBA j I P? R${s t d E sh 8sAs t ej JZs , k j `s Zs >qY +Zs , stI Y Fs Zs d ;HU " ks t Bt{ R R} {ZjsAs RBA j PZ Z B I js R} {$ YZ8sts R} {$sj8 t R $8ZjsIB }B jsR tB% jsR k {Z t BR I {$ t{$s h{{$? Bt I < p G jjR JZ 8 t{st sAs j " ! B ` 8}jB I Rs R$8A$BR$R t {$ t{$s k {$ t{$s h{{$? Bt jB {BtR $ Zk js } B}$s -}jB s{$? Bt R}s{$sj JZ I js 8stB I G jjR k z t Y$9B RBK ts s jBR }$Bt BR I js sR Bt? sZ ${s pBIIs I k %Bt sZt B jsR s{ Zsj R $t% R $ s{$Bt R RBA {jBts{$? Bt k RBA js %$sA$j$IsI I j %$s` t j $ 8}B t ? 8$tBR P? R${BR qsj k {B8B sh 8s _sZj F WsY$t t RZ j$A B q$8 s{Y$t R >d nH ">NsR Y$R B $sR RBA H jBR %$s` R t j $ 8}B tBR Ys{ t } tRs " O R JZ s8}B{B }BI 8BR Bj%$Is j $8}B st }s} j PB 8s $%B I js {$ t{$s h{{$? BtU `Zt B s RZ Ps{ s I t t$8$ t B js {$ t{$s h{{$? Bt {Z8}j {Bt Zt R $B } B}? BR$ B j I -}stI$ js $8s $ts{$? Bt YZ8sts k }B t{$s RZ R}? $ Z { ? ${B 5*? BtI sI${s j $t ? R }B j %$s` t j $ 8}B2 5+Z? sR} { BR Yst {Bt% $IB R RZ K tB t s JZ $}B k R stIs I 8Z{YsR Y$R B $sR I {$ t{$s h{{$? Bt2 +Z$9? sR js PsR{$ts{$? Bt }B js 8 s }BR$A$j$IsI I {B8}s $ -} $ t{$sR {Bt } RBtsj$IsI R I j }sRsIB {B8B psj$j B ? t j I {B stIB js ]s}$jjs 7$- $ts B s{B8}sK W b Bt B e$tR $t }B } R t{$s s $ Z j V ts s ]Bj? Bt t jsR {s sA jsR JZ - tI$ Bt jBR j? 8$ R I js q$ s {BtB{$Is et }sjsA sR I j hj? BRBPB i V 7B tR t "Zts PZ t $8}B st I j $t ? R t j %$s` }B j $ 8}B R tZ R s PsR{$ts{$? Bt t sj }B jB -? B ${B sR? {B8B js P ZR s{$? Bt {ZsR$ $tPst $j JZ s % { R R t $8BR sj % tBR {BthtsIBR sj } R t * R s8BR JZ s jBR A t h{$BR I I R}js9s R s s%? R I j R}s{$B }Z Ist RZ8s R jBR I j I R}js9s8$ t B t j $ 8}B" 5! R j %$s` t j $ 8}B Zt RjsA? Bt 8? sR t js A? ZRJZ Is YZ8sts I js $t8B sj$IsI2 qsj k {B8B Fs{, {* %$ ts s t RZ js B NBR %$s` BR I j $ 8}B tZt{s 8Z t >q$8 q s% j R W % *$ d xH Zt %$s` B I j $ 8}B $t t s ? s jZI$ RZ } B}$s 8Z 5eR R $t ? R t sj }B j %$s` t j $ 8}B Zts sR}$ s{$? Bt j? B ${s2 _BR$Aj 8 t tB {BtRT $ Zks 8? sR JZ Zt 8 B I R B $ s{$Btsj WB BAR st R Ys {Bt% $IB t Zt stY jB I 8sR$sIB {BI${$sIB t Zts }BR$A$j$IsI st PsR{$tst JZ tZ R B { A B R t$ s s sAstIBts js }B {B8}j B VZtJZ tB BIB j 8ZtIB R ? s }B t{$sj8 t $t RsIB t j %$s` }B j $ 8}B Vj ZtBR {B8B jBR sj$ t? tsR I j js B GY t q$8 bsR W b >d E;H I iBA 3 OBZt jB {BtR$I st $t{jZRB Zt I$R}s s eR s ts s{$? Bt I R{ $A js BI$R s I Zt -}jB sIB I j sK tB 1dxE JZ R 8Bt s 8$jjBt R I sK tBR t j $ 8}B Vjj? {B$t{$I {Bt ZtBR - s R R JZ %$R$ st B{sR$Btsj8 t js q$ s et }sjsA sR I ? R BRU "ej %$s` t j $ 8}B R j RZ K tB I Zt jB{B Ns Y$R B $s }sRsIs R ? s {js s8 t R sAj {$Is k tB }Z I R sj sIs O }B jB JZ R} { s sj PZ Z B JZ$? t R$tB Zt $8A? {$j JZ ? s RsA jB JZ j 8sK tsts tBR I }s s ? s " * R% js j PZ Z B }Z I R {$ s8 t } j$ BRB 5]? B8B $t4Z$ ? s t tZ R sR %$IsR j {BtB{$8$ t B I js P {Ys I tZ R s 8Z B I {ZsjJZ$ B B s{Bt {$8$ t B PZ Z B2 ej js B Ns j? t s I js %$Is >N$P TN$t d n H I iBA V < $tj $t {BtR $ Zk Zt RBA A$B ` 8}jB I R
© Los autores, 2001; © Edicions UPC, 2001.
1 (
* $t Bt s e$tR $t
}jst s8$ t BU Zt {$ t ? h{B j IB{ B _$t B $I s Zt I$R}BR$ $%B JZ } 8$ R sAj { {Bt sARBjZ s hsA$j$IsI js P {Ys I I PZt{$? Bt I {ZsjJZ$ $tI$%$IZB jB JZ s Z$ts s Zts 8$ ? sIs I s t{$sR I R Z BR k } B%B{s Zt {sBR RB{$sj Z{YBR R{ $ B R I {$ t{$s h{{$? Bt Yst {BtP RsIB sA$ s8 t RZ R{ } ${$R8B st js %$sA$jT $IsI I jBR %$s` R t j $ 8}B iBA 7$j% A sZ B I tB% jsR {B8B _B j $ 8}B >=} Y N$t d E H B q AsR js I jsR {$ t }Z sR >qY A R BP Y <ZtI I ps R d dH IBtI j I R}js9s8$ t B 8}B sj `Z s Zt }s} j I R s{sIB sh 8s JZ "js Z ?t${s 8? sJZ$ts I j $ 8}B %$sAj `s8? sR $t% t sIs js {BtR $ Zk Zts Y$R B $s I {$ t{$s h{{$? Bt" V YZ ] ]js , {Bth RsU s{ ${s8 t {Bt% t{$IBD I JZ j %$s` t j $ 8}B R $8}BR$Aj " " R Bk {Bt% t{$IB wAZ tB } ? O j } Bj? h{B yRss{ VR$8B% JZ {Z t s {Bt tB% jsR k js BR st 8Aj 8? s ${BR RBA j 8s {B8B ej ht I js t$IsI >qY etI BP e t$ k d xxH B ej t$K t$ B P B >qY = jk N$ j Bk Bt {Bt iBA 7$j% A s js tB% js <$`B I j $ 8}B >]Y$jI BP d xMH w - tI$Is t {BjsAB s{$? q$8 d dHD RBR $ t JZ js Z ?t${s 8st s I %$ s jsR {Bt sI${{$Bt R j? B ${sR t JZ $t{Z t jBR %$s` R t j $ 8}B R RZ}Bt JZ ? R BR tB RBt }BR$Aj R NsR B}$t$Bt R s Ps%B I js }jsZR$T A$j$IsI I jBR %$s` R }B j $ 8}B sZtJZ R{sRsR s8A$? t -$R t iBA N 3B bs I P? R${B k R{ $ B I {$ t{$s h{{$? Bt -} Rs RZ {Bt% t{$8$ t B I JZ sj ? Zt I? s R RZ K tB R Ys ? s sj$IsI k jsR %$ `sR BA` {$Bt R {Bt s j %$s` t j $ 8}B R ? st 8B $%B I AZ jsU "sj ZtBR I tBRB BR tBR 8s s%$jjs8BR s{ {s I RBR hj? BRBPBR st $ ZBR I j R$ jB st } B{Z}sIBR }B jsR }s sIB`sR I jBR %$s` R t j $ 8}B" i RZj s RB } tI t JZ } R s jsR $t{ ? Aj R {Bt sI${{$Bt R j? B ${sR $tY t R sj %$s` t j $ 8}B js P? R${s 8BI ts tB Ysks }BI$IB I R s I ht$ $%s8 t R RZ K tB I j 8ZtIB sj ]$ B R JZ s}s t 8 t tB -$R j k P? R${s sj Zts JZ $8}$Is $ sj }sRsIB k Bt I jsR j k R I Is Zt s} ? Bt I 8stBR B 8s s s $ 8$R8B w -{ } B js }BR$Aj %$Bjs{$? {BtR %s{$? Bt I 8sRs k t ? sD _ B 5 $ t R t $IB } tRs t %$s`s sj }sRsIB k 8s s R s ZtB 8$R8B2 5_Z I Zt YB8A {BtR Z$ Zts 8? sJZ$ts 8Bt s R t j $ 8}B k sR R$ts R s R? 8$R8B t RZ $ ts $tPst{$s2 et R {s}? ZjB $t t s 8BR Is R}Z R s s R sR {Z R $Bt R st PsR{$tst R _B JZ 5R }Z I %$s`s % IsI s8 t }B j $ 8}B2 5ej $ 8}B t RZR 8stBR2 =RBR k sAZRBR I j %$s` t j $ 8}B
ej %$s` t j $ 8}B Ys {BtR $ Z$IB Zt 8s {Z t t js {$t 8s B sP? s I {$ t{$s h{{$? BtU I RI j hj8 A $ ? st${B q$8 3j$ R >d ;;H }$Bt B t j ZRB I Zts 8? sJZ$ts I j $ 8}B s jsR {$ t R d1 8BtBR >d1 Bt, kR d xH B 7 s q ,U } $8 {Bt s{ B >7 s q ,U 3$ R ]Bt s{ d EH }sRstIB }B ej }jst s I jBR R$8$BR >_jst BP Y V} R d EMH B jsR IBR t sR I q 8$ts B >q 8$ts B d M;H >q 8$ts B 1U FZI 8 t *sk d dH 7 $ R {B8B js 8Aj 8? s ${s * GYB >* GYB d EnT H B ej ? Zt j I j $ 8}B >qY q$8 qZtt j d EETE H k I { tsR I }$RBI$BR I qY qb$j$ Y Bt >d x TE;H Ns {BtJZ$R s I j R}s{$B >7 s q , d EET E H 7 s q ,U js tZ %s t s{$? Bt >7 s q ,U qY W - p t s $Bt d M T ;H B eR}s{$B d >7}s{ d d xT H Yst s%$%sIB j $t ? R }B j %$s` t j $ 8}B I RI js } JZ K ts }st sjjs qs8A$? t js - tRs sj ? s I RZ} Y? B R R Ys tZ $IB I js $I s ej } B}$B 7Z} 8st R $ {B8B 8? sJZ$ts I j $ 8}B t I$% RsR B{sR$Bt RU t 7Z} 8st j hj8 >7Z} 8st T qY B%$ d MH I A Ys{ P t s js 8Z I NB$R Nst <sR s t Bt{ R js 8Z YsA? s R$IB Zt
© Los autores, 2001; © Edicions UPC, 2001.
© Los autores, 2001; © Edicions UPC, 2001.
1 1
* $t Bt s e$tR $t
RZ{ RB $ % R$Aj 7? BjB YsR s t Bt{ R <s{$ tIB ZRB I RZR RZ} }BI R 7Z} 8st $t%$ js B s{$? Bt I js q$ sU j $ 8}B B{ I d k tZ R B Y? B {BtR$ Z Rsj%s s RZ } B8 $Is I RZ Ps sj I R $tB W$ js jZ9 RZ}Bt Zt j? 8$ $tP stJZ sAj }s s j YB8A I s{ BU t Zt {? B8${ 7Z} 8st {BtR$ Z B ts s k} Bt st R I RZ I R Z{{$? Bt I R}js9? stIBR s 8skB % jB{$IsI JZ js jZ9 ! B RZ} Y? B 3jsRY j j? s8}s B YZ8stB >qY 3jsRY d (T dH %$s`s s{{$I t sj8 t sj n I 8s 9B I j 1((d sR {$A$ j $8}s{ B I Zt 8$R$j1 t j }$RBI$B $ ZjsIB "_B I jst I j $ 8}B" >d dH =ts R ZtIs -}jBR$? Bt tZ{j s jB I %Z j% RstB k Rsj%B sj } R t et j tB j$ s $B sZtJZ R {BtR$I s s Ns 8? sJZ$ts I j $ 8}B >qY q$8 s{Y$t dM xH I < A p B G jjR js BA s } {Z RB s RBA I R}js9s8$ t BR 8}B sj R js } $8 s 8 t{$? Bt -}j? {$ s s Zt %$s` B I j $ 8}B s}s { t 8B$ R BP Y 1(0_ ] t Z k >d 1MH I j {j? $ B $ jstI? R 7s8Z j sII t et R s R? s $ s RB{$sj j s ? }${B %$s` B I j $ 8}B RZj s R Zt s ?t j I js Zs Is JZ B ts {Bt IB{Z8 t BR BAsIBR I j d M sj sK tB d 1M qs8A$? t
<stIR !& >dMMdH I eIbs I e% <sj R st ${$}s s G jjR Ns BA s ts s js sj s{$? Bt I sj ZtBR }$RBI$BR A? Aj${BR k RZ P { B t j {Z RB I js Y$R B $sU jBR Z ?j $8BR YZ8stBR 8$tst }B st$JZ$js R 8Z Zs8 t t j 8Bt IBtI Z%B jZ s js { Z{$h-$? Bt I ] $R B 7 $R 8 R R I R}Z? R I js s}s ${$? Bt I j js B I <sj j I$ B I j } $? BI${B t BkB JZ$tB qY 7Zt k s8A$? t R{ $ B I {$ t{$s h{{$? Bt eIbs I _s $ {Y jj }ZAj${sAs ej jB` JZ 8s {YsAs
Ys{$s s ? sR >qY ]jB{, qYs G t
s{,bs I dMMdH {BtR$I sIs {B8B }$Bt s t j ZRB I
R I j R$ jB zyD k t js $t{jZR$? Bt I Zts Zts 8? sJZ$ts I j $ 8}B wZt {Z $BRB jB` YBjstI? B I js As sjjs I N $I tD * }s sIB`s 8}B sj wZt `B% t JZ %$s`s sj }sRsIB R $ t Y? Y {YB }Z I t t{Bt s R } { I t R t js j$ s Z s Zt$% Rsj {B8B =t {Z t B I Ws%$IsI >V ]Y $R 8sR ]s Bj dM;nH I ]Ys j R *${, tR B js BA s I s , qbs$tn =t kst, t js
{B I j k V Z B >V ]Btt { ${Z Ost, $t $t V YZ :R ]BZ dMM H ej $t ? R I R} sIB }B js tB% js I G jjR sI${s t RZ s} B-$8s{$? Bt {$ t ? h{s sj {Bt{ } B I %$s` t j $ 8}B $t t stIB YZ$ I j {j? sR${B %$s` 8 t sj k I 8 {st$R8BR {js s8 t $8s $ts $BR {B8B j {Z $BRB jB` I $ {Y jj JZ sj stIs Ys{$s s ? sR $t%$ j {Z RB I j B`${s8 t } $IB t js sIs} s{$? Bt {$t 8s B ? sh{s $jj tt$Z8 >d M HD $ 8}B wsR} { B }s sI?
VZtJZ sj k {B8B s}Zt ? B e$tR $t t d (x js } B}$s B s{$? Bt I js q$ s {Btjj %s Zts I$js s{$? Bt I j $ 8}B RZ P { B R } ? s{ ${s8 t $tR$ t$h{st ej R t $IB I B s{$? Bt I Zt }jst s tB R ? s sRB{$sIB {Bt js I$ {{$? Bt t js JZ 4Zk j $ 8}B * B B 8BIB jBR Y$}B ? ${BR YsA$ st R I z tZR }jst s JZ $ s t R t $IB ? B sIB R I {$ B}Z R B s js q$ s I A ? st %$%$ s js $t% Rs 5q$ t s{sRB R t $IB {Bt{ A$ Zt {${jB I %$Is JZ R $t${$s s t js Z8As }s s s{sAs RZR I? sR t j $tR st I j ts{$8$ t B2 1 ej j hj8 R} {Zjs {Bt js }BR$A$j$IsI I JZ 3jsRY sR R sj{st9sIB }B j 8$R$j Ysks R$IB } B}ZjRsIB sj PZ Z B sj YsA RZ} sIB js % jB{$IsI I js jZ9 eR s Z8 t B sj k {B8B R I$R{Z $ ? s 8? sR sI jst RZj s {B8}j s8 t ? Bt BU j %$s` s % jB{$IsI R RZ} jZ8? t${sR $8}j${s ? s Zt B{ RB t j $ 8}B Zt %$s` sj }sRsIB ej I R}js9s8$ t B Ys{$s j PZ Z B tB R }BR$Aj t sj R {BtI${$Bt R n et j }$RBI$B "q$8 :R V Bb" >d 1H I js R $ I j %$R$? Bt 7 s q ,U js tZ %s t s{$? Bt j } B}$B qbs$t R {Bt%$ t $t R} sIB %$R$ st I j et } $R {B8B {BtR {Z t{$s I Zts I$R{BtT $tZ$IsI 8}B sj d
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
1 n
G jjR I$h{s Zts s8s AsRsIs t sR} { BR s{$Btsj R t jBR {Bt{ } BR RBA j $ 8}B JZ {$ {ZjsAst t js } tRs {$ t ? h{s I js ? }B{s WB t %stB G jjR YsA? s {Z RsIB R ZI$BR RBA 9BBjB ? s k BjB ? s t j iBksj ]Bjj BP 7{$ t{ Ns tB% js I G jjR jsAB s{$? Bt I Zt } $8 $t t B P st{s8 t $tP $B $ ZjsIB qY ]Y Bt${ V BtsZ R >dMMMH R sI jst s s js }ZAj${s{$? Bt I js B ? s I js js $%$IsI R} {$sj I e$tR $t k s js } B}$s $t } s{$? Bt I j $ 8}B {B8B {Zs s I$8 tR$? Bt I A$Is sj 8s 8? s ${B < 8stt $t,BbR,$ wdME;Td ( D et ZtB I jBR }sRs` R I js tB% js j $ttB8$tsIB %$s` B I j $ 8}B sh 8sU "WB Ysk I$P t{$s t j q$ 8}B k {Zsj RJZ$ s I jsR R I$8 tR$Bt R I j eR}s{$B Rsj%B JZ tZ R s {BtR{$ t{$s R 8Z % }B ? j > H * R R}s{$B sj {B8B tZ R BR 8s 8? s ${BR jB t $ tI t R I${ JZ $ t R I$8 tR$Bt R JZ }Z I t jjs8s R NBt $ ZI Vt{YZ s k eR} RB k JZ R R$ 8} I ht$Aj }B P t{$s s R }jstBR {sIs ZtB I jjBR t s ?t ZjB { B {Bt jBR B BR _ B sj ZtsR 8 t R hjBR? Bh{sR R Yst } Zt sIBU 5}B JZ? R I$8 tR$Bt R } {$Rs8 t 2 5}B JZ? tB B s I$ {{$? Bt t s ?t ZjBR { BR {Bt jsR B sR R2 e $t{jZRB Yst $t t sIB {BtR Z$ Zts B8 ? s I ]Zs B *$8 tR$Bt R ej } BP RB 7$8Bt W b{B8A -}ZRB R B t js W b OB , s Y 8s ${sj 7B{$ k Ys{ Zt 8 R s} B-$8sIs8 t " _Z I RZj s }s sI? B`${B JZ G jjR ZtB I jBR }$Bt BR t j ZRB j$ s $B I jBR %$s` R t j $ 8}B R I ht$ s {B8B R{? } ${B st js }BR$A$j$IsI I JZ sj ? Zt I? s R jj s s s {BtR Z$ Zts 8? s JZ$ts I j $ 8}B B} s $%s * ? R j R$ % {B8B Y s8$ t s }s s PZ s Y {YB G jjR tB { t s RZ $t ? R t j } B}$B %$s` e j B} $8$R8B I js ? }B{s %${ B $stsU t RZ %$s` sj I$R st sK tB M(1 (d j %$s` B I R{ZA {Bt YB B JZ js YZ8st$IsI Ys I t sIB t j {st$Asj$R8B Z ?j $8B RjsA? Bt t js I {sI t {sI ts %BjZ $%s I j ? t B YZ8stB Ns { ? ${s RB{$sj {B8B BA` $%B j$ s $B {BtR $ Zk j t -B {B8}s $IB }B B sR tB% jsR I 8? s ${s R$8$js JZ {B8B t js BA s I G jjR B t js }$Bt s 8B$ R BP Y 1( ] t Z k I 7s8Z j sII t $ tB st I j$A sIs8 t js %$sA$j$IsI I jBR 8 {st$R8BR } B}Z R BR }s s j %$s` 7Z ZRB {B8B h{s9 % Y? {ZjB I - s}Bjs{$? Bt I js %BjZ{$? Bt k I j I R $tB I js } B}$s YZ8st$IsI Ys IsIB jZ s s {Z $BRsR BA sR {B8B qb$j$ Y >d ;MH I FBYt G ]s8}A jjU Zt %$s` B I j sK tB n(x R I R}js9s 8$jjBt R I sK tBR Ys{$s j PZ Z B IBtI I R{ZA Zt 8ZtIB {B8}j s8 t BA tsIB }B 8? sJZ$tsR wtB sAj } { I t j$ s $B I js Rs s I Bt$8B I j R{ $ B tB s8 ${stB p B < G $RR }jst s q 8$ts B D 3 st{$R 3js }R ZI? Zts } 8$Rs R$8$js t Vt VI% t Z $t q$8 >d n(H Zt RB } tI t 8ZtIB PZ Z B {Bt BjsIB }B BAB R k }B 8Z` R JZ 8st $ t t s jBR YB8A R {B8B 8 BR $tR Z8 t BR }s s js } B{ s{$? Bt Ns %$R$? Bt I Zt PZ Z B s}B{sj? } ${B Ys R$IB }jsR8sIs t st t? Z8 B I tB% jsR k } j? {ZjsR I j ? t B VR? j hj8 $jj tt$Z8 AsRsIB t js tB% js YB8? Bt$8s I FBYt zs j k > $jj tt$Z8 d MnH } R t s Zt PZ Z B I {sI t k sj s8 t {Bt s8$tsIB I RI j JZ R sj$9st {Bt $tZsR $t{Z R$Bt R t j $ 8}B }s s }BAjs js I$ 98sIs YZ8st$IsI yI? t ${s R$ Zs{$? Bt s js I R{ $ s t j hj8 q B P B8 Y O s x((( >d xMH IBtI Zts %$T ; 0_
et Ns 8? sJZ$ts I j $ 8}B j %$s` B } 8st { st? Bt$8B IZ st BIB j js B _B {Bt s t js } { I t qY ]Y Bt${ V BtsZ R j %$s` B R}BtI sj tB8A I * BR R W AB $}P j ]Z $BRs8 t t js {Bt $tZs{$? Bt sZ B $9sIs I js tB% js I G jjR NsR ts% R I j $ 8}B R{ $ s }B 7 }Y t s- t j { t ts $B I js }ZAj${s{$? Bt I js BA s B $ $tsj j %$s` B s8A$? t } 8st { $ttB8$tsIB sZtJZ IBR I jBR } RBts` R I js BA s Zt 8B jB{, I j PZ Z B k j sj B I j %$s` B R}BtI t s jBR tB8A R I W AB $}P j k BR R R} { $%s8 t ;
© Los autores, 2001; © Edicions UPC, 2001.
1 ;
* $t Bt s e$tR $t
3$ E 1 iBAB R I j PZ Z B t AZR{s I RZR B ? t R s` s I j 8B B sK tB x((( AZR{s YB8A R P? $j R }s s {B8As $ jsR {s t{$sR I RZ 8ZtIB R ? $j et R s {Z $BRs {$t s Zt {$ t ? h{B RBj$ s $B {jZ$IB t RZ jsAB s B $B I 3jB $Is Z $T j$9s Zts 8? sJZ$ts I j $ 8}B }s s R sAj { Zt $t {s8A$B {B8 {$sj {Bt {$%$j$9s{$Bt R I B sR ? }B{sR V s%? R I js 8? sJZ$ts {$A Zts - sK ts R s Zs JZ R stsj$9sIs t I sjj }B Zt s JZ ? BjB B 7Z Is s{$? Bt 8 I$st js ? {t${s I j {s ABtBTd; wd; ]D % js RZj sIBR t s $%BR JZ jj %st sj $t% R $ sIB s P {Ys RZ } B{ I t{$s t j sK tB x((( I j PZ Z B I js q$ s 5_ B JZ? R$ t$h{s Zts Is s{$? Bt t s $%s I d; ]2 Ns Is s{$? Bt I j d; ] R AsRs t js sARB {$? Bt }s {$sj I j {s ABtB } R t t js s 8? BRP s R }B }s I jBR `$IBR %$%BR eR {s ABtB } R t s Zts P s{{$? Bt {BtB{$Is I d; ] ]ZstIB j B st$R8B 8Z j d; ] 8}$ 9s s I R$t T s R {Bt Zts %$Is 8 I$s I ZtBR x n( sK tBR _sRsIB R $ 8}B js 8$ sI I jBR s ? B8BR I d; ] R Yst I R$t sIB yt{jZRB Zt t ? Bh B t P? R${s tZ{j s jj s ? s s js {Bt{jZR$? Bt I JZ js {st $IsI 8? t$8s I d; ] t Zt 8s $sj R { B gtZt{s t s $%s 7$ Zt BA` B st $ ZB PZ s t%$sIB I RI j PZ Z B sK tB x((( ? R tB } R t s ? s } BAj 8sR }s s RZ Is s{$? Bt sZtJZ R j s $AZ$ ? s Zts st $ [ Z IsI n((( sK tBR 8skB JZ js sj w -s{ s8 t js I$P t{$s I $ 8}B t j sK tB x((( k j } R t D 7$ j BA` B YZA$ s R$IB {BtR Z$IB t j sK tB x((( js ? {t${s I j {s ABtBTd; jB Is s ? s {B8B s{ Zsj i RZj s $8}BR$Aj $I t $h{s Zt BA` B } B{ I t I j PZ Z B {Bt I${YB } B{ I$8$ t B ! sR tB% jsR k hj8 R } BPZtI$9st t jBR sR} { BR }R${Bj? B ${BR I j %$s` Ns -} I${$? Bt I j hj8 qY Ws%$ s B >d M H t RZ $t{Z R$? Bt Ys{$s j { t B I js q$ s RZP Zts I$R B R$? Bt 8}B sj JZ js sRjsIs I j sK tB dn;M s tZ R BR I? sR ej RYB{, }R${Bj? B ${B } BIZ{$IB }B j {Bt s{ B {Bt tZ R s {$%$j$9s{$? Bt {Bt s Ps{ BR 8 {? st${BR $t$8s $tsAj R {Bt I$h{$BR I sj Z s % $ $tBRs {Bt {$ jBR RZ {sIBR }B $ st R{BR }? s`s BR I Y$ B RZj s I$P? {$j8 t {Bt{ A$Aj y Zsj8 t RB } tI t R RZj st jsR ? {t${sR I Rs BjjsIsR }B jBR {$ t ? h{BR I j PZ Z B I js } j? {Zjs qY q$8 q s% j R >d E;HU R $t% R $ sIB R I jBR sK tBR E( I R{ZA t s{{$I t sj8 t Zts }Z s I s{{ RB sj PZ Z B NBR Z ?j $8BR % R $ $BR I js {$%$j$9s{$? Bt t js I RBjsIs q$ s I j 1( d jZ{Yst {Bt YB IsR I 8Z st R RZ} %$%$ t R I Zt YBjB{sZR B
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
1 x
tZ{j s et jBR jsAB s B $BR RZA ? st BR I js {$%$j$9s{$? Bt jBR R {$ t ? h{BRN I R{ZA t jBR Z ?j $8BR jB BR I js YZ8st$IsIU Zts P? sA ${s I stI B$I R Zt I$R}BR$ $%B I j stR}B gsR? {B8B Zt s Ps{ B }s s js {ZsI s Z s I j {? {ZjB VZtJZ j RYB{, }R${Bj? B ${B 8? sR { j A sIB t BIs js Y$R B $s I js {$t 8s B sP? s {B R}BtI }BR$Aj 8 t s js R {Z t{$s htsj I ej }jst s I jBR R$8$BR IBtI j sR BtsZ s qskjB {Bt 8}js {Bt $8}B t{$s jBR R BR I js eR s Zs I js N$A sIU sR %s s }B Zt $t{B8} tR$Aj 8ZtIB BA tsIB }B R$8$BR I R{ZA JZ Ys %Z j B s {sRs s RZ sK tB sIs q$ s sj j sIB I Zt 8ZtIB {BtRZ8$IB }B js s B st{$s YZ8sts * RI Zt }Zt B I %$R s ts s $%B j %$s` t j $ 8}B {BtR $ Zk Zt % IsI B {sj $IBR{B}$B Zt {B8}j `B `Z B I 8ZK t {sR ZRsR {Bt 8? Zj $}j R tPBJZ R V tsI$ R{s}st jsR $tht$ sR }BR$A$j$IsI R JZ }BI ? st I $%s R I j %$s` t j $ 8}B VR? j } B s Bt$R s I q$8 q s{, >d xdH I N 7} s Z I ]s8} {BtR$ Z s8sRs Zts % IsI s PB Zts s}BR stIB }B RZ{ RBR {ZkB RZj sIB {BtB{ I st 8stB sR RZR $t{Z R$Bt R 8}B sj R ej } B}$B }sRsIB {BtR $ Zk Zt % IsI B }s s? RB %$ t Zt 7Yst $TNs I js st $ [ Z IsI JZ Ys s s? IB s s%? R I jsR }? s $tsR I h{{$? Bt s s% t Z BR {$ t ? h{BR k }B JZ? tB 8sjY {YB R _B JZ 5s{sRB tB R j }sRsIB j jZ s $I sj IBtI {B8 j { $8 t } P { B2 et qY NsR *sk BP ] s $Bt >* N 9 qs I 7{Y[ B}PZt d MdH I GBjP st F R{Y, RBt P {Z t R jsR $t{Z R$Bt R sj I$R st }sRsIB I js q$ s }s s - s jsR R %sR } Bj? P sR I j ! $ t I$B t Zts s - t s I s st{ j R qs8A$? t js 8$t ? s I j Z st$B R {BI${$sIs }B jBR $t% R $ sIB R I _ B` { sR BIBt >d E1H I ]j$&B I * 7$8s, et R s tB% js j %$s` sj }sRsIB R %$ sj }s s - s stI R {st $IsI R I R 8$t sj st R I RZ I R$t s{$? Bt tZ{j s 7s8 BR,Bb$ 9 } B}Bt Zts I$% $Is } 8$Rs t * s Y BP s *$tBRsZ U Zts {B8}sK t? s {B8 {$sj$9s A$R {R I I$tBRsZ $B {Bt jsIBR {Zks } B{ I t{$s RZj s BA%$s NBR s8st R I js s JZ BjB ? s % ? st {Z8}j$IBR RZR RZ K tBR t qY N$t{Bjt <Zt R >d xMH I G$jRBt qZ{, IBtI Zts {B }B s{$? Bt jjs8sIs q$8 i R s {Y R {Z} s IB{Z8 t BR } I$IBR I j }sRsIB qs8A$? t jBR s8st R I j Z $R8B k I jBR I }B R I $ R B }BI ? st Rs $RPs{ RZR ZR BR } s{ ${stIB js {s9s I I$tBRsZ $BR {B8B t _BA } JZ K tB Z B >_BB N$ j Gs $B d xMH I $st G VjI$RR B %$R$ stIB jBR stI R % t BR I j }sRsIB {B8B js { Z{$h-$? Bt I ] $R B t _B j $ 8}B I iBA 7$j% A Ns - $t{$? Bt I jBR I$tBRsZ $BR R Ys $ $IB {B8B ZtB I jBR }$RBI$BR 8? sR %$R$ sIBR }B jsR tB% jsR RBA %$s` R t j $ 8}B et j $ ? Bt${B z$ ? R$8B %$s` I y`Bt q${Yk s}s {$IB t jBR *$s $BR I jsR R jjsR z$s` R >*9$ tt$,$ b$s9IBb d dH I 7 st$Rjsb N 8 jBR } $8 BR -} $8 t BR P ZR sIBR RBA %$s` R t j $ 8}B } B%B{st $8}B st R sj s{$Bt R t j }sRsIB {B8B jsR js{$s{$Bt R I j ]? s8A ${B k I j _j $R B{ tB j $t{$I t I js qZt ZR,s R$A $sts B js I R Z{{$? Bt I Zt }jst s t jsR B ? A$ sR I s k F? Z}$ JZ B $ $t? B j {$t Z ? Bt I sR B$I R Ns } B}$s - $t{$? Bt I jBR I$tBRsZ $BR $ t RZ {sZRs R ? Zt j js B t Zt -{ RB I sI$s{$? Bt } BIZ{$IB IZ st Zt -} $8 t B et *$tBRsZ R I p V NstI$R js st - $t{$? Bt I RsZ $BR $ t
i RZj s RB } tI t JZ {$ t ? h{BR I jBR sK tBR E( {B8B jBR JZ 8Z R s qY q$8 q s% j R {Bt {BtB{$8$ t BR RZh{$ t R }s s I$R K ts Zt I$R}BR$ $%B I BAR %s{$? Bt I j PZ Z B }Z Ist jj s s sh 8s U "WB 8 ZR s I 8BR s 8$ $ tB st{$s st { A BR st 8$t t R } B 5 -s{ s8 t JZ? R Zt PB ? Bt2" Os t d (x gR $R I? {sIsR st R e$tR $t YsA? s $t BIZ{$IB j {Bt{ } B I PB ? Bt t RZ {s s{ $9s{$? Bt I j jjs8sIB P { B PB B j? { ${B N
© Los autores, 2001; © Edicions UPC, 2001.
1 E
*Â&#x201A; Â&#x20AC;$t Â&#x20AC;Bt s e$tR Â&#x201A;$t
3$ E n y8}Â&#x201E;BAsAjÂ&#x201A;R s s`BR Â&#x201A;8}BÂ&#x201E;sjÂ&#x201A;R s Â&#x201E;s%? Â&#x201A;R IÂ&#x201A; js }st sjjs s8$ s ]sÂ&#x201E; Â&#x201A;j }ZAj${$ sÂ&#x201E;$B IÂ&#x201A; js }Â&#x201A;j? {Zjs qYÂ&#x201A; q$8Â&#x201A; qÂ&#x201E;s%Â&#x201A;jÂ&#x201A;Â&#x201E;R >d E;H
Š Los autores, 2001; Š Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
1
RZ B $ t t j I R%? B sj }sRsIB I 8$R$j R IZ st Zt s sJZ RB%$? ${B 7$t IZIs j 8B B }sRsIB }BI ? s {Bt% $ R t Zt PB 8$IsAj }s s? RB hR{sjU } {$Rs8 t 7$8s, I R{ $A Zts 8} Rs :q$8 VRRB{$s R: JZ B} s j sj8 t t Zt jZ s jjs8sIB jZI }s s $8}Z R BR sj Ysjjs R dx( ((( sK tBR st R I js { s{$? Bt I j }s? R et
sR BIBt$s >d MH I ]j$&B I *
sR BIBt$s k JZ } R s Ysjjs R ZA${sIB t $ B $B I jBR eR sIBR =t$IBR
t j $ 8}B {BtR $ Zk j PZ $B } P { B }s s jBR } j$ BR JZ s{ {Yst s js q$ s Ns tB% js ts s jBR } BAj 8sR JZ B $ $ts j ? -BIB 8sR$%B I js YZ8st$IsI PZ Z s JZ YZk I j s{BRB I I j %$s` t j $ 8}B Yst R{s}sIB sj t$B { s $%B I jBR R{ $ B R I j ? t B
NBR Y$`BR I tZ R BR Y$`BR >!Z ]Y$jI t:R ]Y$jI t d ;H I ]j$&B I * 7$8s, j %$s`
sj B $t% t{$Aj R{s}stIB s tZ R BR I? sR qs8}B{B jsR }B t{$sj R s}j${s{$Bt R 8$j$ s R VR? t js 8 t{$BtsIs _ B` { sR BIBt I ]j$&B I * 7$8s, j I R}js9s8$ t B 8}B sj R Z $j$9s {B8B s 8s R s ? ${s }s s } } s Zts $t%sR$? BtU R t%? s Zts $t t {st $IsI I B}sR sj }sRsIB * RI sjj? R jsR sRjsIs YsR s jsR { {st? sR I Zts }BR${$? Bt I $t ? R 8$j$ s =ts % 9 ZA${sIsR R jsR I %Z j% sj } R t 7$t IZIs j %$s` t j $ 8}B {BtR $ Z$ ? s j s 8s I ht$ $%s stY jsIs }B {ZsjJZ$ `? {$ B
E 1 js
5* t B I {$ t sK tBR BIBR {sj%BR2 q st{ R Y$}t? B ${BR k { $B t$s
* RI $ 8}BR $t8 8B $sj R `Zt B s js } t${$BRs } Bj$P s{$? Bt I }R ZIB{$ t{$sR {B8B j
I R% js jB JZ j I }s s j 8sK tsts i 4 `B I RZR %stBR $t t BR }B I$RBj% Rs I tRs {s}s I t$ Ajs JZ BI s sj ? B I j $ 8}B sj ZtsR { s{$Bt R j$ s $sR Yst -}jB sIB jsR $8}j${s{$Bt R I j %$s` sj PZ Z B Z{YB st R JZ G jjR $ Z8}$ s t js {$ t{$s h{{$? Bt {Bt RZ 8? sJZ$ts I j $ 8}B I {B %${ B $stB B BR sZ B R YsA? st ts sIB ks jsR I R% t Z sR I s{{$I t sj R
s B {s B8st{$s Z B sR } RZt sR s R sI$%$ts B $sR I IZIBRB ? -$ B j YB8A Ys $t t sIB
js B RZ K tB {Bt ` 8}jBR st RBA Rsj$ t R {B8B ]ZstIB I R}$ j IZ 8$ t >GY t Y 7j } Vbs, R dM H I j } B}$B G jjR B NBB,$t s{,bs I 1(((TdMM >dMMMH I eIbs I jjs8k sI${$? Bt {Bt } { I t R st 8B BR {B8B NBR R$ ?P RB I p B $B I qBZ R JZ IZ 8$ Bt IZ st n 1 sK IZ 8$ t R I e tBR B N:Vt * Z $jj +Zs ] t +Zs st >d dH I NBZ$RT7? AsR $ t {$ {ZkB } B s Bt$R s I R}$ s t j R$ jB z g sR Zts R$ R s I R$ R$ jBR VZtJZ }BR$Aj 8 t R s i$} %st G$t,j >i$} 8 {st$R8BR } P $IBR Ys R$IB j I j %st G$t,j dMd H I GsRY$t Bt y %$t js ts s{$? Bt 8? sR {BtB{$Is }B RZ 8skB %$t{Zjs{$? Bt {Bt js j$ s Z s Zt$% Rsj eRs sI${$? Bt Ys {Bt $tZsIB t >d ;(H I *Bt G$j{B- IBtI R IZ 8$ t R }sRst R$ jB k 8 I$B t Zts {? s8s s P $ sIs s js 8} s Z s I j { B sARBjZ B- t{ sIBR
%$s` BR I j $ 8}B stR}B sIBR sj PZ Z B {Bt skZIs I s R 8? s ${sR $t{ ? Aj R =tB I jBR
qY iBAB _ $j
Ns R{sjs , j%$t I 8} s Z s PZ $t BIZ{$Is t P? R${s {B8B Zt $t t B }B I ht$ Zts R{sjs I 8} s Z sR }BR$ $%sR et R s R{sjs js 8} s Z s 8? t$8s I j Zt$% RB j jjs8sIB { B sARBjZ B {B R}BtI s ( -s{ s8 t T1 n, dx 0 ] I js R{sjs { jR$ZR B { t ? sIs WB -$R t$t ? Zt $t{? Bt 8? sR P ? B t j Zt$% RB ]Z $BRs8 t t ZtB I jBR }$RBI$BR {j? sR${BR I js R $ 7 s q , R Ys{ 8 t{$? Bt s Zt BA` B tP $sIB s T1 x 0 ] ]$ s8 t P ? B }Z R I${Ys 8} s Z s $8}BR$Aj R ? s }B I As`B I j { B sARBjZ B wgs T1d Mx D sj B }s {$IB s t{Bt s R 8? sR sj tB I j _BjB WB
-
© Los autores, 2001; © Edicions UPC, 2001.
1 M
* $t Bt s e$tR $t
}B Zt RsA$B jB{B t Zt } { I t I jB JZ Ys % t$IB s I tB8$ts R { $B t$s ? 8$tB s{ZK tsIB }B s j G t t jBR sK tBR E( pZs Is js{$? Bt {Bt j {Bt`Zt B I ? {t${sR Z $j$9sIsR }s s } R %s j {Z }B YZ8stB t {BtI${$Bt R I tP $s8$ t B - 8B 7Z ZRB t tB% jsR I j ? t B R 8Bt s s qY 3 B9 t _$ s >dMM H I G ]js , iZRR jj IBtI R ts s js - sK ts BI$R s I Zt }$ s s P st{? R %$%$IB sR } 8st { R }Zj sIB t j Y$ jB IZ st js BR sK tBR NBZ$R BZRR ts I Z $j$9s Zt } B{ I$8$ t B }s {$IB }s s stR}B s s Zt YB8A {Bt 8T }B ? st B sj PZ Z B t RZ tB% js *$- 8$jj stR IstR Zt AjB{ I js{ >dMM H qs8A$? t ej {s}$ ? st V8? ${s >]s} s$t V8 ${s d (H } 8st { Y$A tsIB As`B Zts {s}s I Y$ jB IZ st {Zs B I? {sIsR t RZ {$ t sIs} s{$? Bt {$t 8s B ? sh{s VZtJZ PZ qY _ BR} { BP y88B sj$ k >d EEH I i ] G e $t js tB% js JZ }B}Zjs $9? B js {Bt js{$? Bt I tP 8BR 8$tsj R }s s R %$%$IBR t Zt PZ Z B t j JZ R I$R}Bt s I 8 I$BR }s s s s tP 8 IsI R JZ YBk }B YBk RZj st $t{Z sAj R eR s Pst ? sR ${s $I s Ys { $R sj$9sIB t tZ R B 8ZtIB sj t js { s{$? Bt I sj ZtsR 8} RsR I R $tsIsR s js } R %s{$? Bt I {sI? s% R }s s RZ t s{$? Bt PZ Z s VR? js ] kBt${R 7B{$ k BP ]sj$PB t$s 8} 9? B s {Bt js {sI? s% R t d E =t PsjjB t j RZ8$t$R B j? { ${B } B%B{? B js I R{Bt js{$? Bt I Zt st t? Z8 B I {Z }BR t d Md {$ {ZtR st{$s JZ 8$t? B j $t ? R }B}Zjs t sj 8} Rs _s { {js B JZ } R sj $8}s sAj s%st{ {tBj? B ${B js $ % R$Aj I t s{$? Bt { jZjs JZ R$ Z s js 8Z tB }Z I $t% $ R _B 8Zk A$ t {BtR %sIB JZ R ? Zt {sI? s% R$ Z R$ tIB Zt {sI? s% O jB R Z$ ? s R$ tIB VR? }B{s { I$A$j$IsI }Z I Is R sj s Z8 t B I "Ns 9Bts t Z sj" >qY W Z sj Bt d MMH }$RBI$B I 7 s q ,U js tZ %s t s{$? Bt IBtI R YZ8stBR Psjj {$IBR t j R$ jB y RBt I %Z j BR s js %$Is }B jBR R %${$BR 8? I${BR I j et } $R sR } 8st { Y$A tsIBR IZ st R{$ t BR sK tBR t Zts ts% R}s{$sj s js I $%s Os t js R $ {j? sR${s Ns {BtJZ$R s I j R}s{$B js $}Zjs{$? Bt I j et } $R t sAs t {Bt s{ B {Bt Zts } $8$ $%s ts% R {ZkB } {$sIB {s s8 t B 1 $}Zjst R t R sIB I Y$A ts{$? Bt %s sAs }B j R}s{$B } BPZtIB I RI d ( w"7 8$jjs R}s{$sj" >7}s{ 7 I d E HD _ R s JZ js { $B t$s {Z t s s{ Zsj8 t {Bt }B{BR sI } BR Ys {BtR $ Z$IB Zt {Z RB P T {Z t 8 t $t%B{sIB t {$ t{$s h{{$? Bt 7Z ZRB {B8B 8 {st$R8B }s s sjs s js jBt %$IsI YZ8sts Ys } 8$ $IB sP Bt s j B I js {BjBt$9s{$? Bt I 8ZtIBR 8B BR 3$j8 R {B8B 1((d Zts BI$R s I j R}s{$B >1((dU V 7}s{ !IkRR k d EMH B Vj$ t j B{ s%B }sRs` B >Vj$ t d H {BtR $ Zk t AZ tBR ` 8}jBR I jjB qs8A$? t V YZ ] ]js , t ]? st ${BR I js j `sts q$ s >qY 7Bt R BP *$R st es Y d MEH I R{ $A Zts Y$A ts{$? Bt s st R{sjs t RZ $t t B I {BjBt$9s 7s st 1 Zt 8ZtIB s x sK tBR jZ9 I js q$ sU Zt 8$jj? Bt I }sRs` BR t R sIB I st$8s{$? Bt RZR} tI$Is NBR } j$ BR I js { $B t$s RBt t$sj8 t stsj$9sIBR t !9k8stI$sR >d 1H I q k ]s IBtI jBR YB8A R Y$A tsIBR t RZR {? s8s sR I { $B t$s JZ } tI t RBA %$%$ s Zts { Z t s Z s I A t Ys{ P t s ZtBR {Z $BRBR jsI Bt R I Z8AsR JZ sj $ Zsj JZ t j e $} B Ps s? Bt${B RsJZ st RZR } t t{$sR ! BR ` 8}jBR RBA Y$A ts{$? Bt }Z I t t{Bt s R t tB% jsR {B8B _Z s sj % stB >qY *BB $t B 7Z88 d MEH I iBA V < $tj $t =t 8ZtIB PZ s I j $ 8}B >V GB jI !Z BP q$8 d EH I Ns k W$% t B ej 8ZtIB sj htsj I j $ 8}B >GB jI s qY etI BP q$8 d (H I 3 I $, _BYj k t hj8 R {B8B e ts8 t `B% t >3B % OBZt d 1H B Z{, iB R > Z{, iB R $t Y 1x Y ] t Z k ZjB nD d H w]s}?
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }sÂ&#x201E;s %$s`Â&#x201A;Â&#x201E;BR IÂ&#x201A;j $Â&#x201A;8}B
1
3$ E ; wVÂ&#x201E;Â&#x201E;$AsD _Â&#x201A;RsI$jjsR 8Â&#x201A;{? st${sR Â&#x201A;t }Â&#x201A;Â&#x201E;8stÂ&#x201A;t Â&#x201A; {Â&#x201E;Z9sIs {Bt Â&#x201E;s js YZ8st$IsIU Â&#x201A;j Â&#x201A;Â&#x201E;8$ts BÂ&#x201E; qTM(( sj IÂ&#x201A;RtZIB wVAs`BD ej qTd((( Zt RBhR ${sIB BÂ&#x201E; st$R8B sRÂ&#x201A;R$tB IÂ&#x201A; }Bj$sjÂ&#x201A;s{$? Bt 8$8? Â&#x201A; ${s 3B B Â&#x201E;s8sR IÂ&#x201A; js }Â&#x201A;j? {Zjs qÂ&#x201A;Â&#x201E;8$ts BÂ&#x201E; 1U Â&#x201A;j `Z${$B htsj >qÂ&#x201A;Â&#x201E;8$ts BÂ&#x201E; 1U FZI 8Â&#x201A;t *sk d dH
Š Los autores, 2001; Š Edicions UPC, 2001.
1M(
* $t Bt s e$tR $t
* RI Zt }Zt B I %$R s 8? I${B R {BtB{$IB j P { B I sj ZtsR I B sR t js } { }{$? Bt I j $ 8}B ej {BtR$ Z$ t R sIB sjZ{$t? B tB }Z I sj s j $ 8B tB 8sj I jBR s{Bt {$8$ tT BR ej } B}$B {s}$ ? st I j et } $R Fs8 R q $ , -} $8 t s Zts s{ j s{$? Bt t RZ $ 8B 8}B sj t RZ t{Z t B {Bt jBR R{sjBR$stBR I "G$t, BP st ek " >d EMH }$RBI$B I js R $ Ns {BtJZ$R s I j R}s{$B ej $ 8B Y$} s{ j sIB I jBR R{sjBR$stBR j R $8}$I R } {$A$IBR }B jBR YZ8stBR _s s {Bt% $ s $ , t }s `s I RZ $ts * js jBR R{sjBR$stBR j Ys{ t $t $ Zts I B s Y$} s{ j sIB s <sA$ Zsj8 t jBR P { BR I jsR I B sR $ tI t s s{ jT s j $ 8B 8}B sj sZtJZ {B8B ks I$`$8BR Zts Y$R B $s {j? sR${s I < p G jjR ej tZ %B s{ j sIB >qY W b V{{ j s B d (dH } R t s js } R} { $%s B}Z R s js R tRs{$? Bt I sj tT $9s{$? Bt I j $ 8}B =t $}B I R$? Bt 8}B sj $tIZ{$Is }B I B sR }Z I t{Bt s R t z$s` sjZ{$tst sj PBtIB I js 8 t >Vj I 7 s R d M(H sIs} s{$? Bt {$t 8s B ? sh{s I js tB% js eR sIBR sj sIBR >Vj I 7 s R d MH I _sIIk ]Ysk PR,k IBtI j } B s Bt$R s t Zt R sIB I {BtR{$ t{$s sj sIs R {Bt%$ t Zt YB8? t$IB } $8$ $%B Zt RjsA? Bt t js js s {sI ts %BjZ $%s $8} Rs t RZR t R ! s BA s RBA R$? Bt t j $ 8}B }B t{$sIs }B js $t R $? Bt I I B sR R ] $} B9B${B >Vt V d E H I $st G VjI$RR JZ Is }$ sj jjs8sIB %$s` 8 t sj et R s {s B ? s I %$s` R 8 t sj R R t{ZsI s GB jI:R _Ys sBt >d n H I t }R ZI? Bt$8B I < t k Z t IBtI j I R}js9s8$ t B 8}B sj R jj %s s ? 8$tB B{Z}stIB j { A B k j {Z }B I Zts } RBts I B s ? }B{s $I s Z $j$9sIs s8A$? t }B yRss{ VR$8B% t RZ js B 5yt {s8A$B `ZR B2 >3s$ e-{Yst 2 d MH Vj ZtBR sZ B R Yst {Z $IB s8A$? t s -{? t ${BR 8 {st$R8BR }s s %$s`s t j $ 8}B I tZjB $t ? R {$ t ? h{B e` 8}jBR tB sAj R RBt $I q$8 i Z t >d xH I i${Ys I s Y RBt sIs} sIs sj {$t {B8B et sj ? Zt jZ s I j $ 8}B >7B8 bY $t q$8 d M(H IBtI j } B s T Bt$R s {BtR$ Z 8Bt s R t j $ 8}B }B 8 s {Bt{ t s{$? Bt B qY O s ;nnM >dMn(H I j ZRB z 3 !IB %R,$ IBtI j %$s` R s ${Zjs 8 I$st st{ R Y$}t? B ${BR VZtJZ }BR$Aj T 8 t j }Z R B I YBtB t jBR 8 {st$R8BR I R{sA jjsIBR }s s %$s`s t j $ 8}B {s$ s Bt$8B I V YZ _B RD t js JZ Zt } BP T t qY < B eJZs $Bt >d x H I _ V YZ w}R ZI? RB $t% t s Zts {Zs{$? Bt JZ j } 8$ sRjsIs R t j $ 8}B g{Bt R? BjB } tRs jB Vj B 8? sR }jsZR$Aj }s { N R *s ,t RR 3sjj >d ;dH I N 7} s Z I ]s8} t js JZ Zt s JZ ? BjB B R stR}B sIB s js iB8s I j sK tB xnx IZ st Zts B 8 t s j? { ${s 8 {st$R8B R$8$js sj Z $j$9sIB t js s8s I ej htsj I js {Z t s s ? sR >qY 3$tsj ]BZt IBbt d M(H =t 8 {st$R8B sj s8 t RZ t }B RZR } {ZR$Bt R RBA js ts Z sj 9s k } B}$ IsI R I tZ R B Zt$% RB R j }jst sIB }B j sR ? BtB8B k I$%Zj sIB P st{? R ]s8$jj 3js88s $Bt t RZ BA s NZ8 t >dMM HU j R}? $ Z I Zt YB8A 8Z B t dME; R 8s $sj$9s t js R jjs ]s} jjs j sR B 8? sR A $jjst I js {BtR js{$? Bt I j ]B{Y B * RI st R$t Zjs 8}js9sT 8$ t B } {$A s{Bt {$8$ t BR st $B R s RZ } B}$s 8Z sj {$A$ js jZ9 } B% t$ t I j }sRsIB I js q$ s VR? {Bt 8}js }$RBI$BR I RZ $tPst{$s B j } B}$B R sjj$IB I js i %BT et Zts R {Z t{$s I j {$ sIB j hj8 $ , I$R}s s RZ s 8s P? sR {Bt s js $ts * js JZ R t{Z t s R{sRs8 t s d 8 I I$R st{$s ej $ 8}B I $8}s{ B I j skB R I R? BjB n d( R {$ {ZtR st{$s JZ tB $8}$I s js $ts AZ js j I$R}s B 7$t 8As B }s s RJZ$%s j skB JZ R s{ {s * js I A % j } B}$B skB JZ R I R}js9s } {$Rs8 t s js % jB{$IsI I js jZ9 * A t Bt{ R t%$s Zts R K tsj s RZ { A B k s{{$Bts eR $8}BR$Aj 8B% R 8? sR ? s}$IB JZ js jZ9 }B jB JZ * js tB }BI ? s jZI$ RZ Ps sj I R $tB
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
1Md
jZ{$? Bt 3 st{ Rs =t 8? BIB $t t$BRB R$t IZIs JZ }s { R s sj sj{st{ I Zts {tBjB ? s s%st9sIsU }s s 8$ s Ys{$s s ? sR t j $ 8}B AsR s ? s {Bt
{s} Z s
js jZ9 8$ $Is t j }sRsIB
%$s `stIB }s s jjB 8? sR ? s}$IB JZ js jZ9 q stR{Z $ Bt dM sK tBR I RI js s}s ${$? Bt I
NZ8 t
YsR s JZ Zt `B% t jjs8sIB VjA e$tR $t }ZAj${s s RZ B ? s I js js $%$IsI R} {$sj Zt % IsI B B } IB s jBR {$8$ t BR I js P? R${s JZ %BjZ{$Bt? B tZ R s {Bt{ }{$? Bt I jsR j k R JZ $ t j Zt$% RB k JZ j ? B js B $ $tsj {Bt` Z s I 3js88s $Bt sj $t st $Aj As? Zj I jBR RZ K tBR P ZR sIBR
E n
W$ BR }R${? B}s sR {sZRsj$IsI k }s sIB`sR =t }Zt B ? t B Zts RP s
=t 9Z8A$IB {s sIB I R ? s ${s sR s j R$j t{$B I js tB{Y jZ8$tBRs t -}stR$? Bt RBA RZR }$ R
_ { I$Is }B Zt R sjj$IB R? Bt${B Zts { $s Z s YZ8stB$I R sj9s 7Z B RB AB s j
7ZR B`BR JZ$}sIBR {Bt R tRB R $tP s B`BR R{ZI $K tst RZ t B tB et RZ 8 t Zts 8$R$? BtU
I RtZIB R{BtI Zt }BI BRB tIB RJZ j B I 8 sj }sRsIB }s s {s8A$s j PZ Z B
5*? BtI R ? st jBR %$s ` BR I j $ 8}B2 js } j? {Zjs
yt{jZRB Zt RJZ$%B %$s` B {B8B j
{kAB
qTM(( I WB RZj s
q 8$ts B
>d M;H R PB B shsIB t }j tB {B s9? Bt I NBR Vt j R
P? s{$j }sRs I Rs} {$A$IB 8? sR s? Zt t Zts ? }B{s {ZksR {BR Z8A R RZj st s` tsR =tB I jBR s Z8 t BR 8? sR {Bt%$t{ t R {Bt s js %$sA$j$IsI I j %$s` t j $ 8}B R js }s t sZR t{$s I %$s ` BR NsR B ? sR RBA I R}js9s8$ t BR 8}B sj R I A t Ys{ P t s R s BA ` {$? Bt }jst sIs B $ $ts $s8 t }B isj}Y 3s j k t jBR sK tBR x( k Z $j$9sIs t B BR }B j P? R${B 7 }Y t <sb,$t t s}BkB s RZ
{Bt` Z s I } B {{$? Bt { BtBj? B ${s
5+Z? $ t j R$ jB
JZ jB Ys{ st }B{B s s{ $%B s jBR { BtBY$R B $sIB R I j PZ Z B2 W$ Zt R? BjB {Bt s{ B t % $t R$ jBR I Y$R B $s 8BI ts s%sjs js %$sA$j$IsI I j %$s` t j $ 8}B 7 Yst $t t sIB
t{Bt s -}j${s{$Bt R s Rs tB sAj Psj s I %$s` BR t j RZ}Z R B JZ j %$s` PZ s }BR$Aj y8s $t 8BR JZ Zt I R}js9s8$ t B 8}B sj JZ$ $ R Zts t ? s } B}B {$Btsj s js IZ s{$? Bt sR {B8AZR $Aj }s s js BR I j %$s` j %sIs s Zts {$ s }B t{$s wsj $ Zsj JZ R t { R$ s 8? BjB jBR %$s` R s js % {$tIsI I js ? }B{s t JZ R $I ? B js 8? sJZ$ts I R}js9s8$ t BR R}s{$sj RDU R? I j $ 8}B R ? st s{{ R$Aj R 7$ js 8? sJZ$ts R YZA$ s I$R K tsIB t Zt PZ Z B 8Zk I$R st et Rs 8$R8s j? t s
tZ R B } {$sIB R$ jB tI ? s }B{sR } BAsA$j$IsI R I R %$R$ sIB iBA V < $tj $t }jst s t
_Z s sj % stB
JZ } R s js PsR{$ts{$? Bt JZ I R}$ s js $I s
I PB B shs js { Z{$h-$? Bt I ] $R B tB -$R t js q$ s t ? s RZh{$ t }s s sP Bt s sj 8} Rs ! s }BR$A$j$IsI s}Zt sIs }B V YZ ] ]js , R $8s $ts j $ 8}B {B8B Zts
s R}$ sj t js JZ R? BjB jsR $Bt R { {stsR s {sIs st$jjB PZ st s{{ R$Aj R w$I s JZ j$8$ s ? s8}j$s8 t jsR BP sR Z ? R ${sR I %$s` }B jBR {B IB R I j $ 8}BD =t s Z8 t B R$8$js s}s { t
qY 7stIR BP q$8
>d n H I _ 7{YZkj $jj IBtI j Rsj B I js R}$ sj R I
E( 8$jjBt R I sK tBR
Vj ZtBR sZ B R RBR $ t t JZ j %$s ` }B j $ 8}B }Z I RZj s s{{$I t sIB et
qY q$8
isk BP FstI s
>d n(H I isk8BtI V _sj8 Zt I$R}BR$ $%B Z $j$9sIB }s s j I R}js9s8$ t B ]B8B RZj sIB j {Z }B I j
8}B sj s{ ? Zs I PB 8s I$R $t s RBA I$P t R 8s $sj R } B s Bt$R s R I$R} Rs s s%? R I j ? B I j $ 8}B
ej %$s` sj PZ Z B tB }s { s } $8 s
© Los autores, 2001; © Edicions UPC, 2001.
1M1
* $t Bt s e$tR $t
%$R s st s $ R sIB VZtJZ {B8B RBR $ t V YZ ] ]js , t Zt tZt{$sIB JZ Ys }sRsIB s I tB8$ts R q { s j k I ]js , {ZsjJZ$ {tBjB ? s RZh{$ t 8 t s%st9sIs RZj s ? s $tI$R $t Z$Aj I js 8s $s =t %$s` B JZ R 8s $sj$9s s t j PZ Z B JZ Is ? s stBtsIsIB st jsR 8Z R sR I Zts {tBjB ? s PsR{$tst $tI R{$P sAj =t B <$8 Ys <s Y I N R I j i k {BtR $ Zk Zt AZ t ` 8}jB I jjB ej js B ts s Zts {Z $BRs $t{Z R$? Bt sj PZ Z B {Bt ht R 8$j$ s R 7$t 8As B j RBhR ${sIB s 8s8 t B I j PZ Z B R{s}s s js {B8} tR$? Bt YZ8sts Ys{$ tIB YBtB s js { s j k I ]js , ! sR BA sR Yst }sRsIB }B sj B j {BtR {Z t $8}s{ B }R? JZ${B I j {Bt s{ B {Bt Zts {tBjB ? s st s%st9sIs VR? t js } j? {Zjs $ j R B} BM gk >d MEH Zt }$jB B I js y pZ s ZtI$sj wd d D jj s sj } R t RZA s Zt Y j${? jB }$jB s R$t t$t ? Zt } BAj 8s Ns } B}$s Psj s I Y$ $ t k js {s t{$s I 8 I${s8 t BR st R R$s k %s{ZtsR }BI ? st RZj s Ps sj R }s s jBR }B t{$sj R %$s` BR et qY < PB I stZR{ $} >d H I i${Ys I ]Bb} Zts {Bt $tZs{$? Bt tB sZ B $9sIs I Ns 8? sJZ$ts I j $ 8}B I < p G jjR j 8$R8B %$s` B I j $ 8}B %$R$ s dEExU Zts s% ? s t RZ 8? sJZ$ts I R t{sI ts RZ 8Z t }j ts IsI 8 I$s sJZ `sIB I } R et ej j$A B I j I? s I j `Z${$B htsj >*BB8RIsk BB, d 1H I ]Btt$ G$jj$R jBR { BtBY$R B $sIB R RBt B} sIBR I s} tI${$ $R k R {sZ $9st js ts $9 }s s %$ s jBR $Aj R Y IB R JZ $8} tst js %$Is I j R$ jB yz qs8A$? t j $8}s{ B }R${Bj? B ${B I Zt %$s` sj }sRsIB }Z I RZj s I Rs sIsAj +Z$9? sR tB }BI ? s8BR R$R $ j $Aj I s8s YZ8stB js {Bt%$% t{$s {Bt ZtsR t R JZ t tZ R B $ 8}B } R t jj %st R$ jBR t sIBR WB } t { 8BR sj }sRsIB t$ R s8BR YsA$ ZsIBR s ? j VR? t qY st GYB ]s8 es jk >d MMH I _BZj VtI RBt Zt RBjIsIB I Zt `? {$ B s{ Zsj R sRjsIsIB sj R$ jB t 8 I$B I Zts B 8 t s j? { ${s _ R s RZ s%st9sIB s 8s8 t B tB {BtR$ Z RBA %$%$ t js A j${BRs yRjstI$s 8 I$ %sj qs8}B{B jsR } R} { $%sR I js tP 8 s JZ s{B8}sK ts s Zt t$K tB t stI Ysj I %Z j s s js } Y$R B $s t ej t$K t$ B P B I yRss{ VR$8B% }s { t 8Zk Ysjs [ Z K tsR VZtJZ R$t t$t Zts IZIs j 8skB I jBR } j$ BR JZ }s { sP Bt s Zt %$s` B I j $ 8}B R j I sj s j }sRsIB NsR PZt R sR {BtR {Z t{$sR Yst R$IB 8s $R sj8 t R$t $9sIsR }B FBYt zs j k t RZ tB% js $jj tt$Z8U "ej %$s` t j $ 8}B R st } j$ BRB JZ {Bt%$ s jsR AB8AsR I Y$I ? B tB t 8 BR sjBR }s s t$K tBR $8A? {$j R +Z$ B I {$ 5JZ? R jB } B JZ }Z I }sRs {Bt Zt s 8s tZ{j s 2 =tBR }B{BR 8$jjBt R I 8Z BRU $%$sj ]Bt j %$s` t j $ 8}B }BI 8BR I R Z$ j Zt$% RB t B B RB I${ js B ? s" NsR sj s{$Bt R {sZRsIsR t js q$ s {ZstIB VI $st 7Y jAB t j I R{ZA $IB I Zt 8 {st$R8B }s s %$s`s t j $ 8}B $t t s jZI$ RZ } B}$s 8Z t js RB } tI t NBR %$s` BR I j $ 8}B tZt{s 8Z t I Fs{, {* %$ RBt Zts 8Z R s 8? sR I jBR } j$ BR $tY t R sj %$s` VZtJZ tsIs {B8}s sAj s js BI$R s I F stTNZ{ _${s I {B8stIst I js ts% et } $R JZ$ t I R Zk BIB % R $ $B I %$Is t js q$ s t j }$RBI$B "Vjj pBBI qY$t R " >d ;H I js R $ I j %$R$? Bt 7 s q ,U js tZ %s t s{$? Bt =ts I$R B R$? Bt 8}B sj } BIZ{$Is IZ st RZ s{{$I t sIB %$s` sj PZ Z B R } B}s s Ys{$s j }sRsIB I js q$ s $tY$A$ tIB js PB 8s{$? Bt I jsR 8Bj? {ZjsR } $8$ t$sR I js %$Is
_ R s jBR R ZI$BR } {Z RB R I N Bts IB Is z$t{$ wd;x1Tdxd D JZ$ t YsA? s {Bt{ A$IB ks t j R$ jB z sj 8 tBR RBA j }s} j Zts 8? sJZ$ts %BjsIB s IB sIs I Zts Y? j${ RZR t sIB s k s B BR sAs`BR tB sAj R j Y j${? B} B tB sj{st9? B Zt I Rs BjjB R$ t$h{s $%B YsR s I R}Z? R I js yy pZ s ZtI$sj M
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
1Mn
Ns j$R s I } j$ BR }B t{$sj R JZ t{$ s j %$s` t j $ 8}B R $t 8$tsAj Vj ZtBR $t{jZRB s}Zt st JZ R}BtRsA$j$IsI R I ? tIBj j sj B 8B sj I A ? st j$8$ s j s{{ RB s I${Ys {tBjB ? sU 5I A ? s `Z9 s R s Zt { $8$tsj }B Zt { $8 t {B8 $IB }B ` 8}jB t Zt PZ Z B 8B B {ZstIB j RZ` B BIs%? s tB Ys ts{$IB2 5O }B Zt { $8 t t j R$ jB zy R$ I {ZsjJZ$ PB 8s js %? { $8s jj %s ? s R$ jBR 8Z s2 5_BI ? s s{ZRs R I A$ s8$s s Zts } RBts {Zks R ZtIs 8Z` ts{ ? s I t B I 8$j sK tBR2 7Bt } Zt sR }s s Zt PZ Z B sAB sIB R} {$sj$R s t I {YB 8}B sj wB }s s Zt %$s` B I j $ 8}B $jZR sIBD 5]Z? st I Rs} {$A$IB }BI ? s }sRs Zt %$s` B I j $ 8}B2 Ns } B}$s $tIZ8 t s $s }BI ? s } R t s Zt } BAj 8s 7 ? Zt j I$ B k R{ $ B tB s8 ${stB Vt YBtk BZ{Y js 8 `B RBjZ{$? Bt R ? s sP Bt s j %$s` {B8B jBR } B s Bt$R sR I q 8$ts B B jBR I js tB% js ej sK tB I j RBj stJZ$jB >qY O s BP Y +Z$ 7Zt d (H I G$jRBt qZ{, U I RtZIBR }BR$Aj 8 t sj B 8 tBR sts{ ? Bt${B JZ {ZsjJZ$ $tIZ8 t s $s $8s $tsAj eR }B t{$sj stBt$8s B Ys R$IB `ZR $h{sIB }B sZ B R JZ B}$tst JZ tsI$ { ? s s Zt Y$}B ? ${B %$s` B I j $ 8}B Ns } B}$s 7s sY ]BttB R {jZ$Is t Zt { t B }R$JZ$? s ${B t j hj8 q 8$ts B 1U j `Z${$B htsj sR I P tI t{s t$9sIs8 t RZ Y$R B $s RBA Zts PZ Z s Z s tZ{j s AsRsIs t j js B I Zt %$s` B I j $ 8}B =tAB t qB8B Bb >d x H I s{, i ktBjIR ts s js {Z $BRs {Bt{ t s{$? Bt I {$ t BR I %$s` BR I j $ 8}B t Zt${Y IZ st js !, BA P R js }B}Zjs h R s I js { % 9s 7ZR }BR$Aj R I %st BR $t{Bt Z t{$sR }BI ? st B{Zj s R As`B j } $R8s I Zts AB s{Y s ! BR js BR {B8B qY 3B- stI Y 3B R >d M(H I isk sIAZ k B k Ws8 $R N $Bt >d ;1H I N R * j i k } R t st s %$s` BR I j $ 8}B %BjZt s $s8 t RB8 $IBR s Zt s s8$ t B JZ$ ? Z ${B }s s AjBJZ s Zts R {{$? Bt I RZ { A B B{Zj stIB sR? BIs $tPB 8s{$? Bt P t sj PZ Z B JZ }BI ? st I R% js I PB 8s $t%BjZt s $s WB% jsR {B8B q AsR js I jsR {$ t }Z sR I iBA 7$j% A 8Z R st {? B8B Zt %$s` B I j $ 8}B t tsIB }BI ? s RZ} s js } Z As I j %$s` t j $ 8}B et R s BA s IBR %$s` BR I R st I RZ 8$R$? Bt t js PsAZjBRs q AsR I js zyyy I$tsR ? s $}{$s nx(( sK tBR st R I RZ ts{$8$ t B sIB} stIB jsR $I t $IsI R I j sR ? BtB8B 7 t8Z T_ sY k I W P Zts Rs{ IB $Rs sj R %${$B I j *$BR yR$R R$t R I R{ZA$ BR IZ st 8? sR I dx sK tBR NsR } {sZ{$Bt R JZ I A ? s sIB} s Zt %$s` B I j $ 8}B %$ t t t$sj8 t RZ8$IsR t jsR }sjsA sR } BtZt{$sIsR }B j } BP RB k t js } j? {Zjs $jj tt$Z8U "ej }sRs` B I j $ 8}B I A R {Z$IsIBRB tB BAR st j }sRs` B I j $ 8}B }BI ? s sj$9s Zt st t? Z8 B I {BRsR _B ` 8}jB }BI ? s BAR %s _BI ? s RsA {Bt -s{ $ ZI JZ$? t I$R}s ? B {Bt s j } R$I t tt Ik k sh 8s ? s s {$ t{$s {$ s jB JZ tBRB BR R? BjB }BI 8BR {Bt` Z s JZ R s8BR I R Zk tIB j }jst s t j JZ %$%$8BR q tI ? s JZ RBA %$%$ {Bt tZ R B j sIB I }BjZ{$? Bt k jjZ%$s s ?{$Is > H qs8A$? t }BI ? s B8s sj ZtsR 8Z R sR R$ 8} JZ tsI$ jsR {Ys s I 8 tBRU s Zs I j B{? stB Zts B{s I j p st ]sK tB ?t _Z I }s { $t{ ? Aj } B j 8? sR 8? t$8B {s8A$B R ? s { Z{$sj Ns I$P t{$s t Zt YB8A JZ R ? s 8Z B k ZtB JZ R ? s %$%B }Z I R } JZ K ts } B 5k Zt YB8A JZ R ? s s }Zt B I 8B $ Zt YB8A JZ tsI$ %Bj% ? s s % %$%B2 < sJZ? js I$h{Zj sI I Ysjjs }sRs` BR I j $ 8}BU Ysk JZ AZR{s jBR IBtI R Z s8 t tB Ysk tsI$ sjj? IBtI Ysk t JZ tsI$ %Bj% ? s s % %$%s `s8? sR" ]sA I {$ JZ s8}B{B -$R t %$I t{$sR I BA` BR sts{ ? Bt${BR - s%$sIBR }B %$s` BR I j $ 8}B }B{B {Z$IsIBRBR {B8B s $I$8 tR$Btsj I ] $R B t j YBjB s8s I js As sjjs I s s YBt w; ( s ] D B js PB B sP? js { Z9 I qY s s YBt _YB B s}Y >d ;H I ]j$&B I * 7$8s, =tB I jBR }s sI$ 8sR I j %$s` t j $ 8}B `Zt B s js 8$ ? sIs I }s BjB ? sR st $B 8 t I R{ $ sR jB {BtR $ Zk t jsR
© Los autores, 2001; © Edicions UPC, 2001.
1M;
* $t Bt s e$tR $t }s sIB`sR 8}B sj R $t BIZ{$IsR }B % 9 } $8 s t <stIR !& I eIbs I e <sj q kR $t q$8 >d nEH I ] N BB R js BA s }$Bt s t RZ s s8$ t B I sjjsIB Ns }s sIB`s }B
jjs8sIsR sZtJZ
et R t $IB s8}j$B R I tB8$ts }s sIB`s s BIs R$ Zs{$? Bt JZ {Bt $ t Zts {Bt sI${{$? Bt B $t{B8}s $A$j$IsI I PB 8s JZ jBAsj8 t }s { {s { I R t $IB -{ j t{$s I j %$s` t j $ 8}B R js I tB8$tsIs } $8 s t
qY q$8 q s Ik
}s sIB`s I j sAZ jB
$t BIZ{$Is }B % 9
>d n;H I isk8BtI V _sj8 sZtJZ R$t Zt st? sj$R$R I sjjsIB
I RZR P { BR
y8s $t 8BR JZ Zt t$ B R t $IB {Bt RZ sAZ jB %$s `s sj }sRsIB k jB sR R$ts et sj {sRB YsA ? s R sIB js %$Is I Zt st { RB k
{ZstIB ? R R BIs%? s Zt 8Z{Ys{YB
YsA ? s $8} I$IB I PB 8s $tI$ { s RZ } B}$s {Bt{ }{$? Bt _ B R$ ? j tB Ys ts{$IB 5{? B8B Ys }BI$IB %$s`s sj }sRsIB k sR R$ts s RZ sAZ jB2 sAZ jBR gR I AZ tBR {Bt %Z R BR t$ BR D w=t {BtR `B }s s %$ s }BR$Aj R }s sIB`sRU
ej sIB I 8sj sA$j$IsI I j }sRsIB {BtR $ Zk Zt sR} { B ? t $8s8 t j$ sIB s js s}s ${$? Bt I }s sIB`sR 5_Z I Zt %$s` B I j $ 8}B 8BI$h{s j }sRsIB {BtB{$IB B }B {Bt s }s ${$}s t j {Z RB I js Y$R B $s I Zt 8BIB }sR$%B2 =ts I jsR } $8 sR R} {Zjs{$Bt R RBA js
}BR$A$j$IsI I sj s j }sRsIB PZ }jst sIs }B <Z B p tRAs{, {BtB{$IB I$ B I {$ t{$s h{{$? Bt s RZR j { B R I js %$R s
V8s9$t 7 ZI$ R
sR I$ s j j tIs $B js B I G jjR
et Zts I jsR 8Z{YsR R}Z R sR {$A$IsR R BP { ? s Zts I$% $Is R $ I {Bt` Z sR I $%sIsR I j } B}$B %$s` U $8s $t 8BR TRBR t? s Zt j { B T JZ j $t% t B I Zts 8? sJZ$ts I j $ 8}B %$s `s sj PZ Z B k t%? s js 8? sJZ$ts sj }sRsIB I PB 8s sZ B8? s ${s js 8? sJZ$ts gtB t { R$ s ? s $t% t s js }s s %$s`s sj PZ Z B 7$ RZ
kB
}sRsIB {$A Zt
! s R$ Zs{$? Bt }s sI? B`${sU
YB8A %$s`s sj PZ Z B k } R t{$s RZ 8Z ? s ${s sR ? {B8B RZ } B}$B PZt sj } R t k I {$I RZ${$Is R sj tB }BI RB}B s sj Z AsIB s %$R$? Bt
i Rs sj
_ B R$ 8Z t j
} R t 5JZ? R -s{ s8 t jB JZ Ys } R t{$sIB t j PZ Z B2 O htsj8 t 5JZ? B{Z $ ? s R$ sj Z$ t %$s`s s sj }sRsIB k s{sAs s {sR? stIBR {Bt RZ 8sI 2 }sI 2 57 {Bt% $ ? s t RZ } B}$B
Vj ZtsR I R sR $I sR }$Bt sR Yst % $IB t tB% jsR {B8B >d ;dH I N is}Ys j B j 8s $R sj js B
qY BZ Y q$8
qY st GYB 7sb qBIBR %BRB BR 9B8A$ R >Vjj OBZ VR ? t
B8A$ R d x H I iBA V < $tj $t Ns sj s{$? Bt I jBR s{Bt {$8$ t BR }sRsIBR Ys R$IB s8}j$s8 t -}jB sIs }B tB% jsR k } j ? {ZjsR I j ? t B
=t A $jj$st RZ`
>d (H
I F i$ sZ sR$R $8BR sj {Z $BRB sR R$ts B I F RZ{ $R B s 8stBR I Zt %$s` B I j $ 8}B {ZstIB ? R BIs% ? s s Zt t$K tB O t
V $R B j stI Y pZt
>d 1H I N 7} s Z * ]s8} ] I PB 8s JZ
Zts -} I${$? Bt 8}B sj %$R$ s s V $R ? B j R t js j `sts p {$s I j n;( s j $t4Zk t hj? BRBPB R IZ{sIB I s{Z IB {Bt j
8? BIB {$ t ? h{B
]B8B {BtR {Z t{$s j
%$s ` B s} {$s $8}B st R {s8A$BR sR RZ B tBU j } B RB R Ys sj t $9sIB k ? j 8$R8B 8$ts {Bt% $IB t R{js%B
ej }s} j s{ $%B I jBR %$s` BR I j $ 8}B }BI ? s I R t{sI ts s% R sj s{$Bt R I j }sRsIB {ZksR PZt R sR {BtR {Z t{$sR }BI ? st sP { s sj } B}$B } R t VR ? t
Vt{ R sj zB${ R >d nnH
I Ws 7{Ys{Yt Zt %$s` B I j $ 8}B 8s s s ZtB I jBR YZtBR I V $js t j sK tB ;x1 ytR st ? st s8 t x( ((( I R{ tI$ t R I ? R I Rs}s { t $t{jZk tIB sj } B}$B %$s` B JZ $t{$I t sj8 t s I R{ tI$ t I j YZtB *${Ys {Bt` Z s {BtR $ Zk js AsR s Z8 t sj I hj8 R {B8B
q 8$ts B
IBtI jsR 8? sJZ$tsR I j PZ Z B 1(1 $t t st sj s j {Z RB I js
Z s {Bt s jBR YZ8stBR sR R$tstIB t j }sRsIB s js JZ R ? s 8sI I j PZ Z B j? I I js R$R t{$s qs8A$? t jBR Y 8stBR {3jk I
i RB sj PZ Z B
>
s{, B Y 3Z Z d MxH
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
1Mx
3$ E x NBZ$R sj $8B js $t ? }$Is %$s` s I j $ 8}B R{ Z stIB jBR P { BR I RZR $t{Z R$Bt R 8}B sj R t j }sRsIB 8 I$st Zt %BjZ{$Bts $B I$R}BR$ $%B et js PB B sP? s $tP $B jBR {Bt BjsIB R I j $ 8}B w5 ? }j${sR YZ8stsR I j s B I !92D I { ? }$ s Y t{$s I Zts YZ8st$IsI RZ8$Is t j B{sRB 3B B s8sR I js } j? {Zjs $jj tt$Z8 >d M H
© Los autores, 2001; © Edicions UPC, 2001.
1ME
* $t Bt s e$tR $t
}s { t I RI$AZ`s R t Zts PB B sP? s I j } R t sR j t{Z t B PB Z$ B t s k k RZR } B}$BR }sI R t j 8B B d xx `ZR B t j I? s t JZ ? R BR R {BtB{$ Bt ! B {Z $BRB s Z8 t B }Z I t{Bt s R t ej RBt$IB I Zt Z tB >V 7BZtI BP qYZtI d M(H I isk sIAZ kU {ZstIB Zts -} I${$? Bt }s Ys{$s j I$R st }sRsIB s }s ${$}s t Zts {s{ ? s I I$tBRsZ $BR js 8Z s{{$I t sj I Zts 8s $}BRs sj s I PB 8s R$ t$h{s $%s j {Z RB I js st R tR$Aj RZj s js %BjZ{$? Bt s Y$R B $s *${YB js B {BtIZ{ s js RZ t } Zt s I {Z? } JZ K tBR {s8A$BR $t BIZ{$IBR t PsR R st $B R 7$t IZIs Zt 8s I I As k 4 -$? Bt WB BIB j 8ZtIB Ys $t } sIB jsR }s sIB`sR I j %$s` t j $ 8}B {B8B } Z As $ PZ sAj I RZ $t%$sA$j$IsI qsj k {B8B sh 8s j hj? BRBPB *s%$I N b$RU " j %$s` t j $ 8}B RBR t B R }BR$Aj NsR }s sIB`sR I j %$s` t j $ 8}B RBt s 9sR tB $8}BR$A$j$IsI R" 5+Z? RBjZ{$? Bt R Ys IsIB s js -$R t{$s I }s sIB`sR2 WB -$R Zts RBjZ{$? Bt I ht$ $%s t ? 8$tBR P? R${BR sZtJZ js j? B ${s RZ $ JZ js $t` t{$s t j }sRsIB tB }Z I {Bt sI {$ tZ R s -} $ t{$s =t %$s` B I j $ 8}B tB }Z I R s js %$Is I RZR } B t$ B R $8} I$ RZ ts{$8$ t B R$8T }j 8 t g}B JZ RZR }sI R Yst jj sIB s sIZj BR k ? j Ys ts{$IB qYB8}RBt:R q$8 q s% j$t qY B k >d ;;H I B G $R$t {BtR $ Zk Zts 8Z R s {js $%$I t I %$s` t j $ 8}B JZ s}B s Zts {Z $BRs RBjZ{$? Bt s js }s sIB`s I j sAZ jBU Zt YB8A R 8Bt s t j $ 8}B YsR s dM ( }s s sR R$ts s RZ sAZ jB ej %$s` B I j $ 8}B j I$R}s s I jj tB t js {sA 9s k j sAZ jB }B t Bt{ R {Bt R? BjB d; sK tBR I IsI R I R}jB8s s RZR }$ R V RZ B tB s d ;n 1 YB8A R {Z t st {? B8B jBR sj 8st R YsA? st I R Z$IB js {$ZIsI I WZ %s OB , t d 1( ZRstIB sR % t tBRB ej %$s` B {BtR{$ t I JZ js 8Z I RZ sAZ jB Ys sj sIB j {Z RB I js Y$R B $s I {$I RZ${$Is R st R JZ %$%$ Zts sj$IsI JZ tB R js RZks 7$t 8As B jBR 1 YB8A R RZj st R I 8 t R YZ$IBR I Zt P tB}? s ${B gO jsR PB B sP? sR I j sAZ jB sIZj B R$ 8} Yst 8BR sIB RZ Ps8BRs {${s $9 } BIZ{$Is IZ st Zt BR{Z B $t{$I t t RZ $tPst{$s ej sAZ jB I qk} b $ 3 B8 Y 3Z Z >d x(H I _ GB Y R{s}s s8A$? t I js $ s I Zt t$ B % t s $%BU {ZstIB j %$s` B I j $ 8}B Rs I RZ $t{Z R$? Bt sj }sRsIB }s s sR R$ts s RZ sAZ jB {B8} Z As JZ Ys {B8 $IB Zt B gWB s RZ sAZ jB * tZ %B j R t $IB {B8? Zt RZ $ JZ R$ Zt sAZ jB Ys sj{st9sIB js 8sIZ 9 {ZsjJZ$ $t t B }B sRT R$ts j t RZ `Z% t ZI RZj s ? s P? Z $j eR s9Bts8$ t B R $t t{$BtsIs8 t $ tB sIB t Ns } $8 s 8? sJZ$ts I j $ 8}B >3$ R q$8 s{Y$t d xMH I 3 I ${ Bbt Zt $tJZ$ st js B RBA jsR {BtR {Z t{$sR I sj s j }sRsIBU j $t% t B I Zts 8? sJZ$ts I j $ 8}B 8Z R s RZ { s{$? Bt s R s8$ BR =tB I jjBR R 8Bt s E( sK tBR t j }sRsIB k sR R$ts s RZ sAZ jB Ns Y$R B $s B8s j $ 8}B } R t k htsj$9s {ZstIB j $t% t B I Zts 8? sJZ$ts I j $ 8}B 8Z R s RZ { s{$? Bt s IBR s8$ BR qs8}B{B }s { YsA t { R$IsI I Zts }Bj${? s I j $ 8}B {Zks } R t{$s t hj8 R {B8B q$8 {B} >q$8 {B} d ;H t tB% jsR {B8B js {$ sIs _B j $ 8}B I iBA 7$j% A B t js BR {B8B $ RZAj$8 } B}? BR$ B > k !A` { Vjj 7ZAj$8 d EdH I _BZj VtI RBt {B $ jBR P { BR } BIZ{$IBR }B $t` t{$sR t j }sRsIB * RI Zt }Zt B I %$R s P? R${B js j? B ${s I jBR %$s` R t j $ 8}B Ys % $IB t j I tB8$tsIB } $t{$}$B I sZ B{BtR$R t{$s JZ RBR $ t JZ jsR Z ?t${sR RBjZ{$Bt R %? sj$IsR RBt sJZ jjsR jBT Asj8 t sZ B{BtR$R t R eR B R js {sZRsj$IsI tB R $t%B{s R ${ s8 t } B R JZ$
_s sI? B`${s8 t tB R -}j${s js {sZRs }B js JZ js {s9s I I$tBRsZ $BR tB B{sR$Bts sjT s{$Bt R t js Y$R B $s 7$t IZIs RZ } B}$s {s? Is } BIZ{$ ? s js 8Z I B sR 8Z{YsR R} {$ R
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
1M
Zts {BtR$R t{$s j? B ${s t js R {Z t{$s I jBR s{Bt {$8$ t BR et R R t $IB js 8 s -$R tT {$s I Zt }B t{$sj R} { sIB I j }sRsIB $t%$R$Aj $ts{ $%B JZ tB Is ? s jZ s s }s sIB`sR }s { tB t 8Z{YB R t $IB 7? BjB Ys -$R $IB Zt }sRsIB Zt $tR st t j {B8}j `B I s8s I j Zt$% RB {Bt Zt }s B k Zts Y$R B $s I ht$Is ej }sRsIB tB R }$ IBR % { R * R s 8st s js Ps8BRs }s sIB`s I s{Z8Zjs{$? Bt JZ $t BIZ{ iBA 7$j% A t RZ tB% js _B j $ 8}B IBtI % t BR {js% I js Y$R B $s I js YZ8st$IsI R {Bt%$ t t }Zt BR I t{Z t B I YB IsR I %$s` BR I j $ 8}B tB tI ? s t$t ? Zt R t $IB qs8}B{B Zt %$s` B I j $ 8}B }BI ? s Rsj%s s FZsts I V {B I 8B $ t js YB Z s t$ s tt Ik I RZ Ps sj s t sIB WB }BI ? s R$JZ$ s sR R$ts sj 8$R8? R$8B <$ j st R I RZ sR{ tRB sj }BI gR$8}j 8 t }B JZ j %$s` B I j $ 8}B tB R t{Bt sAs sjj? }B sJZ j t Bt{ R _B{B { ? I$ B JZ Is ? s s8A$? t }s s j sR Z B %$s` B I qY i$t I p <ZI { JZ {BtR$ Z s8sRs Zts % IsI s PB Zts % tI$ tIB j 8$R8B I$s8st sIJZ$ $IB ; % { R t j V8R Is8 I j R$ jB zyy B }s s js YB $}$jst } R} { $%s I Zt 8ZtIB {Bt ((( IZ}j${sIBR I <$ j sj k {B8B N R I j i k tBR } R t s t k Ws8 $R N $Bt qs8}B{B jBR $tPB ZtsIBR %$s` BR I j $ 8}B I js }B}ZT js R $ I j %$R$? Bt ej ? Zt j I j $ 8}B } R s tB $t P $ t j {Z RB I jBR s{Bt {$8$ t BR }sRsIBR }BI ? st $ $ R {B8B R $ BR I stI R % t BR I js YZ8st$IsI {B8B j s sJZ s _ s j <s ABZ js Z}{$? Bt I j %Bj{? st s,s Bs j YZtI$8$ t B I j q$ st${ B j I R 8As {B I WB 8stI? s Ns $t8Z sA$j$IsI I j }sRsIB tB R ? s R ${ s8 t j$ sIs s js $t%$sA$j$IsI I j %$s` t j $ 8}B 7$ tB }BI 8BR sj s j }sRsIB }BI 8BR $t t s sP { s jB I PB 8s RZ $j 7 s s t {ZsjJZ$ 8BIB I tB $t{Z $ t t$t Zts sj s{$? Bt I jBR $R BR Y$R ? B ${BR < sJZ? j YB8A > YBjI Y st d E H I ${Ys j BB {B{, {BtR $ Zk Zt }s sI$ 8s I R s } R} { $%sU Zt %$s` B I j $ 8}B %$R$ s psj$j s t $ 8}BR I ] $R B _s s RZ RB } Rs F R? ZR R R? BjB Zt sRsIB 8 t sj JZ %$% {Bt s ? s k FBR? qsj R RZ P ZR s{$? Bt JZ j %$s` B I {$I sIB} s RZ $I t $IsI gk s{sAs 8Z $ tIB t js { Z9 ej }sRsIB tB Ys R$IB sj sIB eR 8? sR js }s ${$}s{$? Bt s{ $%s I j %$s` B I j $ 8}B Ys Y {YB }BR$Aj j {Z RB I jBR s{Bt {$8$ t BR }sRsIBR ej {B B8 s` P st{? R Ns F >d EnH w %$R$ sIB t j hj8 d1 8BtBRD {BtR $ Zk B B ` 8}jB tB sAj q sR Zts Rst $ t s yyy pZ s ZtI$sj js RZ} h{$ R R Ys {Bt% $IB t Zt I RBjsIB $sj IB8$tsIB }B js sI$Bs{ $%$IsI NBR {$ t ? h{BR {jZ$IBR t Zt $t $t{sIB 8ZtIB RZA ? st B Yst I Rs BjjsIB j %$s` t j $ 8}B =t YB8A BAR R$BtsIB {Bt Zt {Z IB I RZ $tPst{$s wjs 8Z I Zt YB8A s js {s s }B jBR }sR$jjBR I j }s $R$tB s B}Z B I ! jkD R t%$sIB sj }sRsIB IBtI R ts8B s } I$Is8 t I Zts 8Z` * %Z j s sj } R t k jZI$ tIB Zts tZ %s 8$R$? Bt }B jBR {B IB R I j $ 8}B I {$I %Bj% `Zt B s RZ s8B t j }sRsIB 7Z {$ s j jj %s sj s B}Z B I ! jk IBtI R sAs $IB }B ZtB I jBR %$s` BR I j $ 8}B JZ $t t s $8} I$ RZ YZ$Is Vt R I 8B $ {B8} tI JZ RZ BAR R$%B {Z IB R j I RZ } B}$s 8Z k JZ Zt kB 8? sR `B% t I A R s t RBR } {$RBR $tR st R {Bt 8}jstIB RZ ? s ${B ht 5+Z? RBjZ{$Bt R Ys s}B sIB js {$ t{$s h{{$? Bt s js -$R t{$s I }s sIB`sR2 ]B8B RBR $ t yRss{ VR$8B% jsR }s sIB`sR $tY t R sj %$s` t j $ 8}B {BtR $ Zk t js } Z As $ PZ sAj I RZ $t%$sA$j$IsI ! BR sZ B R Yst s ${ZjsIB Zts $8s $ts $s R j {{$? Bt I I$R}BR$ $%BR B sI R }s s -}jB s jBR % ${Z BR I j $ 8}B R$t sj s j {Z RB I jBR s{Bt {$8$ t BR et qY 7BZtIT7b } >d dH I F p sjjs I R {BtR Zk t s{Bt {$8$ t BR }sRsIBR }B 8 I$B
© Los autores, 2001; © Edicions UPC, 2001.
1MM
*Â&#x201A; Â&#x20AC;$t Â&#x20AC;Bt s e$tR Â&#x201A;$t
3$ E E z$s`stIB sj }sRsIB }sÂ&#x201E;s Ys{Â&#x201A;Â&#x201E; }jsZR$AjÂ&#x201A; Â&#x201A;j }Â&#x201E;Â&#x201A;RÂ&#x201A;t Â&#x201A; *Â&#x201A; js }Â&#x201A;j? {Zjs @ &*J*4 >d1 Bt,Â&#x201A;kR d xH
Š Los autores, 2001; Š Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
1M
I j RBtB%s{ Zt s}s s B JZ } 8$ $R s jBR RBt$IBR {BthtsIBR t jBR 8Z BR I Zts $ j R$s =ts {Z $BRs %s $st I R s $I s s}s { t j js B }$Bt B qY z${s $Bt >d 1EH I ps It <Zt $t IBtI Zt - sK tB I$R}BR$ $%B {B R{ tsR k RBt$IBR $8} RBR t j ? q s% j $t q$8 >d nEH I $ {Y jj } R t s js 8} %$R$? Bt JZ } 8$ {BtR Z$ js Y$R B $s I Zt BA` B qs8A$? t js {$ t 7$ %$R sR I js s st s !jIZ%s$ >7 % t z$ bR BP !jIZ%s$ pB d xH I $, i Rt${, -}jB s Zts $I s }s {$IsU x ((( sK tBR I R}Z? R I js - $t{$? Bt I js YZ8st$IsI Zt Z}B I sj$ t? tsR R ZI$s j ks{$8$ t B s JZ Bj? B ${B I !jIZ%s$ k {BtR Zk $tR st ? st sR I js Y$R B $s I js s9s YZ8sts s }s $ I jBR RZ{ RBR $8} tsIBR t R tIBR Z tR$j$BR YsjjsIBR t js 9Bts ? sR PsR{$tst RZj s s? Zt j { BtBR{B}$B I ej$8$ts $Bt >d ;MH I FBYt G ]s8}A jj JZ } 8$ tB R? BjB R{ Z s j }sRsIB Bt 8BI ts I js {j? sR${s ABjs I R$tB } % BIBR jBR s{Bt {$8$ t BR PZ Z BR }BR$Aj R w% R$? { $R sjD qs8A$? t q$8 B8A >d xxH I G$jRBt qZ{, Ys{ ZRB I Zt {Z $BRB I$R}BR$ $%B js { BtB{? s8s s JZ } 8$ hj8s js R{ ts I Zt { $8 t gst R I JZ ? R R } BIZ9{s =ts RZ R $%s $I s } R t sIs }B $st G VjI$RR t ] $} B9B${B {BtR$R t js $t } s{$? Bt I j %$s` t j $ 8}B {B8B I R}js9s8$ t B s B s sj$IsI NBR %$s` BR R ? st 8 BR R} { BR R $ BR 8ZIBR I j {Z RB I js Y$R B $s R$t }BR$A$j$IsI I $t P t{$s t jBR s{Bt {$8$ t BR eRs %$R$? Bt I j %$s` B I j $ 8}B - t B I j$A sjA I ? B I js }BR$A$j$IsI I }s ${$}s{$? Bt s{ $%s $t` t{$s {Bt RZ t B tB Ys I$R ZR sIB s st t? Z8 B I R{ $ B R k {$ t ? h{BR Vj ZtBR {B8B s $t ps It RBR $ t t JZ "{ZstIB Zt %$s` B I j $ 8}B } t s t j }sRsIB ? R R t { Rs $s8 t sj sIB Ns Z ?t${s }BR$A$j$IsI I RBj% jsR {Bt sI${{$Bt R j? B ${sR { sIsR }B sj } 8$Rs R RZ}Bt JZ j Zt$% RB R A$PZ {s t s8sR R }s sIsR t j $tR st t JZ R } t s t j }sRsIB" eR {Bt{ } B I A$PZ {s{$? Bt I j Zt$% RB }s I Zts {Z $BRs $t } s{$? Bt I js 8 {? st${s {Z? st ${s I A$Is sj P? R${B <Z Y e% wd x D Ns -$R t{$s I Zt sAst${B I R sIBR }BR$Aj R }s s Zt R$R 8s }BI ? s $t } s R {B8B Zts RZAI$%$R$? Bt I js sj$IsI t Zt$% RBR 8? Zj $}j R t jBR JZ {sIs R$R 8s sIB} s ? s Zts I jsR }BR$Aj R RBjZ{$Bt R *${Ys $t } s{$? Bt I 8Z{YBR 8ZtIBR s8A$? t jjs8sIs B ? s I jBR Zt$% RBR }s sj jBR Ys IsIB jZ s s {Z $BRsR { s{$Bt R { t sIsR t js sj s{$? Bt I t NB JZ j $ 8}B R jj %? B > $t Y FZA$j d xnH I Gs I }$RBI$BR I js Y$R B $s@ VR? BB j t sj N sts js As sjjs I p kRAZ k j 7Z R $ {B8B % t{ IB I js pZ s ]$%$j s8 ${sts NsR s{{$Bt R I Zt { BtBY$R B $sIB JZ R 8Bt s sj dMEn }s s R ZI$s js As sjjs } BIZ{ t Zts A$PZ {s{$? Bt I j Zt$% RB t 8? Zj $}j R {B}$sR IBtI j {Z RB I js pZ s ]$%$j R I$R} Rs t Zts }j? ksI I }BR$A$j$IsI R WZ R B Zt$% RB {B R}BtI ? s s js {B}$s t js JZ j WB 8$t? B IBAj stIB sj 7Z ! s Y$R B $s { t sIs t j {Z RB I Zts {Bt $ tIs t R s B{sR$? Bt js PZt R s pZ s ]$%$j R}sK tBjs R ej {Bj {{$Bt$R s I R jjBR >d EH I ]? Rs sjjB JZ? IBtI R R jjBR I j $8s $ts $B $tB I qYZj Zt{st j } RZt B $ZtPB }ZAj${stB w sR js 8Z I 3 st{B t d n D t %${ B $s I j P t ts{$Btsj sR sj s j {Z RB I jBR s{Bt {$8$ t BR qs8A$? t j t%? B I 8 tRs` R sJZ$? Bt${BR I RI j PZ Z B {BtIZ{ s js A$PZ {s{$? Bt I j Zt$% RB t ] BtB}s$Rs` >q$8 R{s} d M(H I p B k tPB I et Zts I jsR tZ %sR sj$IsI R j } B}$B F 3 tt Ik RBA %$% s RZ Ps8BRB s t sIB t *sjjsR
Vj ZtBR js BR I j R$ jB y YsA? st R$IB }$Bt BR t j ZRB s Z8 t sj I Zt$% RBR sj tsT R F < iBRtk V$t? B Ns Y$R B $s I $%BR e` 8}jBR tB sAj R RBt =t sZ 8BtI >dM xH I j P st{? _js t >dM H I j } Bj? h{B < p G jjR @
© Los autores, 2001; © Edicions UPC, 2001.
* $t Bt s e$tR $t
et _s%sts >_s%st d EMH I $ Y iBA R R I R{ $A Zts q$ s }s sj js IBtI js ytT JZ$R${$? Bt k js $ j R$s BR t st j {Bt Bj {Zj Z sj t Zts eZ B}s st{jsIs t j }sRsIB k IBtI js {$ t{$s R Ys {Bt% $IB t Zts IB{ $ts } BY$A$Is =t$% RB I jB{BR >GYs sI =t$% R 2 d ; H I j t$sj 3 I ${ Bbt {BtR $ Zk Zts R? s $ s IBtI Zt I$ B R sRjsIsIB s{{$I tT sj8 t s Zt Zt$% RB }s sj jB IBtI js q$ s R Ysjjs $t8 Rs t Zts $ ? st${s As sjjs {Bt s9sR - s R R ! sR tB sAj R { s{$Bt R IBtI jBR Zt$% RBR }s sj jBR `Z st Zt }s} j I R s{sIB RBt =t st$jjB sj I IB I j 7Bj >i$t V BZtI Y 7Zt d xnH I ]j$&B I * 7$8s, IBtI Zt R$8}j RPZ 9B 8 t sj } 8$ sj } B s Bt$R s s{{ I s Zts q$ s }s sj js ZA${sIs t B B Zt$% RB B NBR } B}$BR I$BR R >qY pBI qY 8R j% R d 1H I yRss{ VR$8B% IBtI Zts { $R$R t ? ${s 8ZtI$sj R RZ j% 8 I$st j $t {s8A$B I t ? s {Bt Zt Zt$% RB }s sj jB qs8A$? t Ns jj sIs I jBR s BR {Z? st ${BR >qY ]B88$t BP Y +Zst Z8 ]s R d MEH I 3 I $, _BYj {BtR $ Zk Zts {B8}j `s s8s IBtI R t 8 9{jst Y$R B $sR }s sj jsR {Bt Bt } RBts` R {B8B iBtsjI i s st s $jkt Bt B F 3 tt Ik y 9Ys, V9$8BP wjs % R$? R I Zts BI$R s IBtI js 8 s RB%$? ${s I yRss{ VR$8B%D B j } B}$B 7 }Y t <sb,$t s s%? $t` t{$s t B B Zt$% RB {Btjj %s Zt P { B Bs{ $%B t tZ R B } B}$B Zt$% RB Ns $t } s{$? Bt I 8Z{YBR 8ZtIBR I js 8 {? st${s {Z? st ${s Ys R$IB s8A$? t %$R$ sIs t j $8s $ts $B Zt$% RB q , Os t "ej Ps{ B sj ts $%B" >qY Vj ts $% 3s{ B d E H }$RBI$B I js R $ {j? sR${s j {s}$ ? st Fs8 R q $ , t s t {Bt s{ B {Bt Zt Zt$% RB I st $8s $s ej } B}$B $ , k B BR R 8$ 8A BR I js $}Zjs{$? Bt I js ts% et } $R RBt stR}B sIBR s B B 8BI jB I et } $R JZ RZ {s Zt Zt$% RB sj ts $%B t "eR} `B R} `B" > $ B $ B d E H qs8A$? t 7 s q ,U js tZ %s t s{$? Bt Ys -}jB sIB j {Bt{ } B I sj$IsI R sj ts $%sR t }$RBI$BR {B8B "ej et } $R I j sk " >O R Isk:R et } $R d (H B t "Vjj pBBI qY$t R " >d ;H et "_s sjj jR" >d nH GB P j Z ?t${B $}Zjst I js s9s ,j$t Bt s AB IB I j et } $R -} $8 t s Zts - sK ts sj s{$? Bt JZ j jj %s s BR{$js } $Is8 t t IBR sj$IsI R {Z? st ${sR et j {$ sIB }$RBI$B R I R{ZA JZ GB P } R t s Zt } hj {Z? st ${B s t$% j s ? B8${B I$R $t B I {ZsjJZ$ B B {Z }B t j Zt$% RB 7$t 8As B js 8 {? st${s {Z? st ${s RBR $ t JZ tB -$R t t -BR I Zt$? Bt t jBR }BR$Aj R R sIBR I Zt R$R 8sU js -} $8 t s{$? Bt h`s js sj$IsI qs8A$? t j hj8 qY p$st 7}$I yt%sR$Bt >d xH I R{ $A {? B8B j ? stR$ B I Zt 8${ Bs Z` B t B sA Zts }Z s I s{{ RB s B B Zt$% RB }s sj jB I RI j JZ 8 t ZtsR $ st R{sR s sK tsR I dx 8 I I$? s8 B JZ R$ 8A st j }? st${B t Zts stJZ$js }BAjs{$? Bt I G$R{BtR$t w=7VD * Y {YB js } R t{$s I Zt {Z }B I st $t tRs s% IsI t jsR } B-$8$IsI R I js q$ s {B8}B s ? s Zts R $ I P { BR 8Z{YB 8? sR tB sAj R JZ jBR JZ 8Z R s j hj8 ! B }BR${$Bts8$ t B st js } {ZR$? Bt I jsR }s sIB`sR 8}B sj R Zs Is js{$? Bt {Bt js h`s{$? Bt I jBR s{Bt {$8$ t BR }sRsIBR 3 $ 9 N $A 8Z R s jB I$P? {$j JZ RZj s sj s j }sRsIB t RZR js BR I js R $ I js Z s I j {s8A$B et }s ${Zjs t yt t s {s8A$s j }sRsIB >q k stI ]Yst Y _sR d xMH $t BIZ{ js I tB8$tsIs j k I {BtR %s{$? Bt I js sj$IsI JZ RBR $ t JZ jBR {s8A$BR } } sIBR t j }sRsIB R s8B $ Zst ? s}$Is8 t k tB I `st sR B =t }jst s8$ t B R$8$js }Z I t{Bt s R t N R *s ,t RR 3sjj I N 7} s Z I ]s8} B t 7 %${$B I %$ $jst{$s >3$ Gs {Y d M1H I ]Btt$ G$jj$RU } R s jBR RPZ 9BR I Zts { BtBY$R B $sIB s t%$sIs sj NBtI R I d ;( }s s $t t s Rsj%s js {s I sj
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
@
I 7 _sZj I jBR AB8As I BR sj 8st R js Y$R B $s R$ Z RZ {Z RB $t -B sAj 5+Z? B{Z $ ? s R$ j sR BtsZ s I <B8A I RZ $ 8}B > st $t <$R q$8 d ExH I $st G VjI$RR JZ sR Rs I Zt %$s` s s }Z I % n n( 8$tZ BR t j PZ Z B I {$I$ s AZ js RZ I R $tB k sj s RZR s{{$Bt R2 *$R}BtI ? s I sj ? Zt $ 8}B 8? sR JZ j P? R${B s ? B8${B I j hj8 q$8 Rj$} >d xEH {Zks } { }{$? Bt PZ Z s R j$8$ s R? BjB s x R ZtIBR 8? sR sjj? s I j } R t Vj ZtBR sZ B R t js j? t s I js {Bt` Z s I } B {{$? Bt { BtBj? B ${s I 7 }Y t <sb,$t s}Zt st s JZ js ts Z sj 9s tB R$R jsR }s sIB`sRU R$ R PZ 9s j =t$% RB s jjsR ? R }BI ? s I R t{sI ts P { BR I %sR sIB R jB JZ FBYt zs j k {sj$h{s {B8B B ? s I j I$R ZR B {? BR8${B =t ` 8}jB I R s $ ? Bt${s {Bt` Z s js } B}B {$Bts qY ]B $IB R BP q$8 >d EEH I _BZj VtI RBtU Zt YB8A I j R$ jB {jZ sIB }B Zt %$R$ st PZ Z B } Zt sU "5+Z$ I {$ JZ ZR I R {s8A$st j }sRsIB2" V jB JZ j 8$R $BRB %$R$ st R}BtI U "!Y tB WZt{s eRB R $tY t 8 t $8}BR$Aj 7$ sj Z$ t jB $t t s s t{Bt s ? s RZ{ RBR JZ P ZR s ? st RZR $t t BR NB JZ Ys R$IB R" ! B ` 8}jB }Z I t{Bt s R t j js B I 3 I ${ Bbt ej -} $8 t B >qY e-} $8 t d x;HU "ej } BP RB FBYtRBt RBR $ t t RZ 8stB Zt {ZAB I js ? Bt V jsR 1Ux; I js s I sh 8s JZ I }BR$ s ? s j {ZAB s jsR nU(( RBA js }js sPB 8s I RZ 8? sJZ$ts I j $ 8}B k jB t%$s ? s sj }sRsIB -s{ s8 t s jsR 1UxxU u _B {BtR$ Z$ t TYs{ tB s T s jsR R 8 tBR {$t{B j {ZAB I A ? s RPZ8s R I 8$ 8stB k 8s $sj$9s R t js }js sPB 8s {$t{B 8$tZ BR st R I JZ kB jB {BjBJZ sjj? u 5]? B8B }Z I ZR I {BjB{s jB sjj? t Bt{ R2 u } Zt ? B ZtB I RZR {Bj sR u NB JZ }sRs ? s R JZ sj s{ {s 8 R RPZ8s ? s I js }js sPB 8s k s}s { ? s RBA 8$ 8stB }s s JZ kB jB I }BR$ sjj? V jsR 1Uxx j {ZAB R RPZ8s I js 8stB I j } BP RB FBYtRBt k s}s { RBA js }js sPB 8s sj YsA R$IB t%$sIB Ys{$s s ? sR {$t{B 8$tZ BR t j $ 8}B }B P { B I RZ PZ Z s s{{$? Bt I {BjB{s j {ZAB RBA js }js sPB 8s s jsR R t }Zt B u 57 Ist {Z t s2 ]$t{B 8$tZ BR st R I JZ kB jB {BjBJZ sjj? g R ? s sjj? u _ B TBA` s Zt {Bj s P Zt{$ tIB j { K tBT 5JZ? RZ{ I ? s R$ sYB s JZ ks Ys s}s {$IB {$t{B 8$tZ BR st R I JZ ZR I jB {BjBJZ t js }js sPB 8s {s8A$s I B}$t$? Bt k tB jB {BjB{s t jjs s jsR R2 5WB R } R t s ? s sj ? Zt $}B I }s sIB`s2 ej } BP RB FBYtRBt R $8s JZ R s s I Zts $I s $t Rst _s s % JZ? RZ{ I jj sIsR jsR R t }Zt B B} s }B tB {BjB{s j {ZAB t js }js sPB 8s ej {ZAB R$ Z IBtI R sAs _ B j =t$% RB t B $t{jZk tIB sj } BP RB FBYtRBt RZR {Bj sR k js 8? sJZ$ts I j $ 8}B I Rs}s { t " et js 8$R8s j? t s j }s ${$}st I Zt RsPs $ t }j ts s RB9B${s I V pZt PB *$tBRsZ >d MH I N 7} s Z I ]s8} I {$I Ys{ Zt %$s` t j $ 8}B sj I? s st $B k 8s s s jBR Z? sR JZ jB Yst $8}B ZtsIB ej $t t B I sj s j }sRsIB } B%B{s js s}s ${$? Bt I PZ 9sR R}s{$BT 8}B sj R JZ B tst j YB8A s RZ } R t gY {YB sK t${BR et e$tR $t:R $I >d H I FBYt ] s8 jsR $t` t{$sR I Zts {$%$j$9s{$? Bt - s R t j {Z RB I js Y$R B $s 8$tst }B I R Z$ j } B}$B Zt$% RB
© Los autores, 2001; © Edicions UPC, 2001.
* $t Bt s e$tR $t
ej R{ $ B Ns k W$% t R BIs%? s 8? sR {Bt ZtI t t RZR s} {$s{$Bt RU "7$ Zt Zt$% RB } 8$ js }BR$A$j$IsI I j %$s` t j $ 8}B k I sj s j }sRsIB t Bt{ R t$t Zts 8? sJZ$ts I j $ 8}B R ? s `s8? sR {Bt{ A$Is t sj Zt$% RB" et RZ } B}$B js B iB s $t ]$j$tI R stI Y _BRR$A$j$ k BP pjBAsj ]sZRsj$ k z$Bjs $Bt >d H k st js }BR$A$j$IsI I JZ Zt JZ$}B I {$ t ? h{BR Z $j${ {$j$tI BR I q$}j }s s %$s`s }B j $ 8}B j Zt$% RB I {$I j$8$ts js }BR$Aj }s sIB`s 8s stIB s jBR $tR $ sIB R I js 8? sJZ$ts {Bt js RB } tI t -}jBR$? Bt I Zts tB%s R${BR FBYt =ts RZ t{$s htsj }s s js 4 -$? BtU I s{Z IB {Bt j } $t{$}$B st ? B}${B @@ jBR P? p $AA$t k s $t i R s}Zt st JZ jBR sR} { BR }s sI? B`${BR I j %$s` t j $ 8}B tB R ? st sj8 t }s sIB`sR g -{ } B {ZstIB YZA$ s sj Z$ t JZ R } B{Z}s s }B jjsR VR? t Zt Zt$% RB IBtI js %$Is tB YZA$ s I R 8AB{sIB t R R IB sIBR I {BtR{$ t{$s j %$s` t j $ 8}B }BI ? s t Zts }BR$A$j$IsI I R %$sAj VY? R tsIs E ; Ns P? R${s I jBR %$s` R t j $ 8}BU jBR %$s` R Zt$I$ {{$Btsj R I js js $%$IsI R} {$sj
ej R$ jB Ys %BjZ{$BtsIB j {Bt{ } B k js PB 8s I %$s`s <s R$IB R $ B I Zt ts{$8$ t B t j $t ? R }B jBR %$s` R Rs %? s I R{s} I BIB R YZ8stB {Bt stR$sR I s% t Z s qBIs % 9 JZ js q$ s Ys R$IB ks -}jB sIs {sR$ }B {B8}j B k jsR }BR$A$j$IsI R I t{Bt s Zts $Rjs {Bt B $jsR $ st R {B8B $t Bt B `Zt jsR %? t R $ $IsR {B8B $tBR I YB8A RT8BtB R Yst I R%st {$IB js YZ8st$IsI Ys h`sIB RZ $t ? R t js {BtJZ$R s I j R}s{$B Ns %BjZ{$? Bt {tBj? B ${s I j R$ jB R Ys %$R B {B BtsIs {Bt jBR } $8 BR sjZt$9s` R {Bt j t%? B I RBtIsR R}s{$sj R s 8ZtIBR I$R st R JZ t sj ZtBR {sRBR Yst sAstIBtsIB j 7$R 8s 7Bjs Z8AB s jB I R{BtB{$IB eRs }Z ts t{s t$9sIs t eR sIBR =t$IBR k js - $t s =i77 }B sts js {s s R}s{$sj t }j ts Z s P ? s tB RZ}Bt 8? sR JZ Zts sh 8s{$? Bt I jsR stR$sR I {BtJZ$R s I j YB8A k I RZ $tts s t { R$IsI I -}jB s tZ %BR YB $9Bt R et Zt PZ Z B tB 8Zk j `stB jsR } $8 sR RBtIsR R}s{$sj R $}ZjsIsR RZ {s ? st j {BR8BR s js A? ZRJZ Is I tZ %sR $ sR I }s s? RBR %? t R _BI ? st JZ$9? sR I$jZ{$Is j % IsI B }s} j JZ I R 8} K ts js s9s YZ8sts t R %sR B Zt$% RB JZ YsR s js P {Ys R R$R s 8BR s B BR R$ tBR I %$Is 8? sR sjj? s I jsR P Bt sR I tZ R B 8ZtIB s9Zj eR B I {BjBt$9s B BR R$R 8sR }jst s $BR Ys ? s s4B s js } {s $ IsI I tZ R s {tBjB ? s k 8? sR s? Zt jsR j$8$ s{$Bt R I j } B}$B Zt$% RB t j JZ YsA$ s8BR _jst s JZ js % $ $tBRs } B R$? Bt I js YZ8st$IsI t j tB {tBj? B ${B jj s ? s s Zt j? 8$ }Z I RZj s {$ s8 t s% t Z sIB ej YB8A R {B8}j `B {Bt`Zt B I s ? B8BR JZ Ys sIJZ$ $IB s s%? R I 8$jjBt R I sK tBR I %BjZ{$? Bt Zt RB } tI t R sIB I {BtR{$ t{$s Ys R$IB {s}s9 I {Bt Bjs j PZ B I I Rs Bjjs Y s8$ t sR k 8? sJZ$tsR I 8BI js RZ t B tB et jBR Z ?j $8BR {$ t sK tBR Ys %$R B ej } $t{$}$B st ? B}${B PZ RZ $IB }B j P? R${B stIBt ]s t d ; k RBR $ t JZ jsR {s s{ ? R ${sR A? sR${sR I j =t$% RB {B8B RZ s8sK tB k IsI sR? {B8B jsR j k R JZ jB BA$ tst RBt RZj sIB I tZ R s } B}$s -$R t{$s k I A t R {B8}s $Aj R {Bt jjs _s s Zt R ZI$B I sjjsIB I jsR $8}j${s{$Bt R I js B ? s }Z I {BtRZj s R qY Vt Y B}${ ]BR8BjB ${sj _ $t{$}j >d MEH I FBYt * s Bb k 3 st, F q$}j @@
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
1 n
]ZsI B E d _ $t{$}$BR I js js $%$IsI R} {$sj Ns B ? s I js js $%$IsI R} {$sj R AsRs t IBR s-$B8sR B }BR ZjsIBR } B}Z R BR }B VjA e$tR $t t d (xU d NsR j k R P? R${sR RBt $I? t ${sR t BIBR jBR R$R 8sR I P t{$s $t {$sj R JZ R 8Z % t Zt$PB 8 8 t t R? 1 Ns % jB{$IsI I js jZ9 t j %s{? B { R {BtR st wk I %sjB 1 3 1, ;xM ,8bRD $tI } tI$ t 8 t I {ZsjJZ$ 8B%$8$ t B js $%B t 8$RB k { } B
{Z8}j$IB j RZ K tB I ? y{s B %$ tIB sj9s R s jBR } $8 BR s%$Bt R JZ Yst }jst sIB RBA Zts RZ} h{$ } B R$%s8 t 8? sR }BAjsIs NBR } {s $BR 8BI jBR I Rs BjjsIBR s } $t{$}$BR I R$ jB Yst }sRsIB j j %B s jBR 8BI tBR s{ B R {s}s{ R I AsRs js 8? ${s As s I j RBt$IB ej } B RB s%st9s % $ $tBRs8 t Ys{$s Zt 8ZtIB {s s{ $9sIB }B stR}B R 8? sR ? s}$IBR k R Z BR s Zt $ 8B JZ }s { $8}s sAj 7? BjB js {B8} tR$? Bt I jsR j k R JZ $ t tZ R B Zt$% RB Ys % jsIB js -$R t{$s I Zt % IsI B j? 8$ ts Z sj I % jB{$IsI R eR s } I${{$? Bt PZ s% t Z sIs }B Zt P? R${B sj 8? st t d (x 8$ t sR I Rs BjjsAs RZ s s $R t Zts Bh{$ts I }s t R I 7Z$9s 7Z tB8A VjA e$tR $t wdM ud xxD k RZ BA s js B ? s I js js $%$IsI %BjZ{$Bt? B js sj$IsI P? R${s Ns st s}B s{$? Bt I e$tR $t s js P? R${s I j R$ jB Ys R$IB I B{s j {s ? s{ sARBjZ B I {Bt{ } BR {B8B 8sRs jBt $ ZI k $ 8}B JZ % t? st R$ tIB $t } sIBR I RI jBR $ 8}BR I psj$j B k W b Bt {B8B } B}$ IsI R P? R${sR Zt$% Rsj R $tI } tI$ t R I j BAR %sIB Ns B ? s I js js $%$IsI R} {$sj R AsRs t IBR BtU js s-$B8sR B }BR ZjsIBR w]ZsI B E dD I jBR JZ R I R} tI Zts $8}B st $8}j${s{$? % jB{$IsI I js jZ9 R {Bt%$ t j j? 8$ RZ} $B I % jB{$IsI R }s s {ZsjJZ$ {Z }B B t
© Los autores, 2001; © Edicions UPC, 2001.
1 ;
* $t Bt s e$tR $t
I tZ R B Zt$% RB W$t ? Zt BA` B }Z I %$s`s s 8skB % jB{$IsI JZ js jZ9 ej Zt$% RB sZ B Zjs RZ j? 8$ I % jB{$IsI {Bt%$ $? tIBR t RZ } B}$s }Bj${? s sj? s{ ${s I ? sh{B WB -$R t {s j R I t sIs s jsR sZ B}$R sR I j Zt$% RB JZ sI%$ st RBA j j? 8$ I % jB{$IsI } 8$ $IB }Z R B JZ jBR }BR$Aj R $tP s{ B R I Rs j k tZt{s jj s ? st s $t{Z8}j$ js WBR t{Bt s8BR st Zt j? 8$ ts Z sj I j Zt$% RB O tB -$R Zt j$A B I {js8s{$Bt R }s s s tI tZ R sR JZ `sRU jsR j k R I j Zt$% RB R{s}st I j }BI I 8st$}Zjs{$? Bt YZ8stB et tZ R B } JZ K tB 8ZtIB js % jB{$IsI I js jZ9 tB {BtR $ Zk Zt j? 8$ R ${ $%BU js jZ9 $t%$ Zts 8$t? ZR{Zjs P s{{$? Bt I R ZtIB t {B Zts I$R st{$s {B8}s sAj sj I$? s8 B R =t Ys9 jZ8$tBRB 8$ $IB I RI js RZ} h{$ jZts t { R$ s s} tsR d n R ZtIBR }s s { Z9s js I$R st{$s JZ js R }s s I js q$ s V? Zt js jZ9 8$ $Is }B j 7Bj AsK ts js q$ s M 8$tZ BR I R}Z? R I R 8$ $Is sR %s s }B j R}s{$B $t }jst s $B s jB js B I {sR$ dx( 8$jjBt R I ,$j? B8 BR 7$t 8As B j $ 8}B t { Rs $B }s s t%$s Zts R K tsj s VjPs ] t sZ $ js R jjs 8? sR } ? B-$8s sj 7$R 8s 7Bjs RZ} s jBR ; sK tBR WBR R }s st ZtBR $ B st n( ((( sK tBR jZ9@ I j { t B I js psjs-$s k sZtJZ Rs I$R st{$s } B%B{s Zt j$ B %? tZ R s -} $ t{$s {B $I$sts tB } R t s 8? sR JZ Zt 8 B }sR B }B js B $jjs I R $t8 tRB B{? stB {? BR8${B _s { sARZ IB jZ{ZA s RBA }BR$Aj R $8} $BR sj? s{ ${BR B sR Bts% R JZ P {Z t st jBR { t BR I 8skB s{ $%$IsI {B8 {$sj t Zts IB{ ts I sjs-$sR {ZstIB jBR $ 8}BR I %$s` R ? st j$8$ sIBR }B js ht$ ZI I js % jB{$IsI I js jZ9 7? BjB jsR 8 t R 8? sR $8s $ts $%sR 8 I$st - sB I$ts $BR s s`BR s s%? R I j jjs8sIB Y$} R}s{$B Yst 8st t$IB %$%B j RZ K tB I Zt $8} $B YZ8stB - tI$IB YsR s jBR {Btht R I j Zt$% RB {BtB{$IB eR j? 8$ $8}Z R B }B js % jB{$IsI I js jZ9 BAj$ ? B s e$tR $t s $t } s I 8$tsIBR {Bt{ } BR P? R${BR A$ t R sAj {$IBR t j {Bt - B I js P? R${s {j? sR${s {B8B js 8sRs js jBt $ ZI IB I Zts k j $ 8}B w]ZsI B E 1D ej {Bt{ } B I $ 8}B t js $%$IsI R} {$sj }s { - s? tB% js Pst ? sR ${s V I$P t{$s I js %$R$? Bt {j? sR${s j $ 8}B stR{Z s Zt $ 8B I$R $t B t PZt{$? Bt I js % jB{$IsI I j BAR %sIB VR? Zt A % js}RB I $ 8}B }s s Zt sR BtsZ s JZ R sj `sR I js q$ s s st % jB{$IsI }BI ? s sIZ{$ R t I? sR R 8stsR B { t ts R I sK tBR }s s j }jst s q$ s eR s I$js s{$? Bt I j $ 8}B $R sIs st B }B jBR jB` R I js ts% {B8B s t$% j A$Bj? B ${B k }R${Bj? B ${B tB } R t s Zt P t? B8 tB s}s t R$tB JZ {B R}BtI s Zt sRB sj t j $ 8B {Bt JZ 4Zk j $ 8}B NsR $8}j${s{$Bt R JZ R I $%st I js I$js s{$? Bt I j $ 8}B R Yst stsj$9sIB s t$% j ? B ${B 8 I$st js I tB8$tsIs }s sIB`s I jBR 8 jBR w3$ E DU Zt sR BtsZ s \ sAstIBts js q$ s s AB IB I Zts ts% JZ sj{st9s % jB{$IsI R } ? B-$8sR s js I js jZ9 7Z 8 jB 4 } 8st { t tZ R B }jst s * R}Z? R I sj ZtsR I? {sIsR I %$s` j sR BtsZ s \ Rs s js q$ s 7ZR IBR % R$Bt R RBA j 4Z`B I j $ 8}B RZj st {Bt sI${ B $sRU }s s 4 j sR BtsZ s \ R Ys sj `sIB I js q$ s s st % jB{$IsI }B jB JZ j $ 8}B t j $t $B I js ts% R Ys sj t $9sIB ]B8B {BtR {Z t{$s 4 I A YsA t% ` {$IB 8? sR JZ RZ 8 jB \ _B {Bt s I RI j $t $B I js ts% R}s{$sj \ Ys BAR %sIB {? B8B js q$ s u{Bt RZ 8 jB 4 u R sj `sAs I RZ R$R 8s I P t{$s _B jB st B j $ 8}B I A ? s YsA R sj t $9sIB }s s 4 U \ I A ? s YsA t% ` {$IB 8? sR JZ RZ Y 8stB 4 7$t IZIs s8AsR {Bt{jZR$Bt R tB }Z I t R R$8Zj ? st s8 t {$ sR qsj k {B8B s}Zt ? B e$tR $t JZ$ t PZ j } $8 B t }jst s js Ps8BRs }s sIB`s t RZ s ? {ZjB I d (x s8AsR P t{$sR tB RBt R$8? ${sR ej sR BtsZ s \ Ys s{ j sIB }s s sAstIBts js
ej sK tB jZ9 R Zts Zt$IsI I I$R st{$s JZ$%sj t sj sk { B {B $IB }B js jZ9 t Zt sK tB !;E d(@ ,8 @
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
N
q$ s R Ys sj `sIB I ? R s k Ys P tsIB $t% $IB RZ 8B%$8$ t B }s s Rs s js q$ sU RZ Y 8stB " Ys } 8st {$IB t js q$ s k R sYB s Zt YB8A 8? sR %$ `B =ts $I s st PsR{$tst tB }BI? s R{s}s s js Y? sA$j }jZ8s I jBR R{ $ B R I j ? t B JZ js Yst Z $j$9sIB {Bt RZ I$R}s t st t? Z8 B I ts s{$Bt R =t ` 8}jB $tJZ$ st R j BP {$IB }B ej }ZRY >qY _ZRY d MdH I FBYt zs j k et R js B Zt sIZj B t sAjs js{$? Bt {Bt Zts t$K ts JZ `Z s t Zt }s JZ VZtJZ js YsA$j$IsI I zs j k tBR jj %s s s% t Z s Zt BR{Z B BA` $%B j sIZj B RZj s R Zt R$8}j sR BtsZ s JZ I A }s $ t Zts ts% js $%$R s _s s ? j RZ s% R? s R } BjBt s ? s }B ZtBR }B{BR 8 R R _ B I A$IB sj P { B I js I$js s{$? Bt I j $ 8}B js q$ s YsA ? s t% ` {$IB %s $sR I? {sIsR s RZ %Z j s qBIBR RZR Ps8$j$s R s8$ BR k {BtB{$IBR ks{ ? st t js Z8As Ns t$K ts R {Bt%$ t Zts s sIZ s R t $8 t sj {Bt RZ }sRsIB Zt % R $ $B RZ Z ?j $8s R} st9s I %Bj% s % {Bt %$Is s sj Z$ t JZ {BtB{$? B t js q$ s t RZ q$ s ej 8$R8B P t? B8 tB I js I$js s{$? Bt I j $ 8}B } 8$ s Zt $t ? }$IB YZ8stB %$R$ s j 8ZtIB ts sj I jBR stI R R K tB R jBR I 8Bt? s{BR sj$ t? tsR I js tB% js I V YZ ] ]js , ej ht I js $tPst{$s >]Y$jIYBBI:R etI d x;H JZ jj st s js q$ s I RI js sjs-$s Wp7 x; E 1 s ;( sK tBR jZ9 I I$R st{$s qs8A$? t j $tR$ t etI G$ $t j? I YZ8stB t js jZ{Ys {Bt s js s9s I jBR $tR { B R RBA %$% sj $t -B sAj I % t$ I j $ 8}B t ej FZ B I etI >etI :R ps8 d MxH I ! RBt 7{B ]s I NsR $8}j${s{$Bt R I js I$js s{$? Bt I j $ 8}B t Zts {BtP Bt s{$? Bt s 8sIs t IBR s9sR sj? s{ ${sR {BtR $ Zk t js AsR s Z8 t sj I js tB% js Ns Z s $t 8$tsAj >qY 3B % Gs d xH I FB <sjI 8stU jBR RBjIsIBR YZ8stBR jZ{Yst {Bt s ZtBR YBR $j R sj$ t? tsR jBR sZ $tBR t Zts {Bt $ tIs s R{sjs sj? s{ ${s {Zks js s IZ s{$? Bt Ys Y {YB Bj%$Is jsR {sZRsR }B jsR JZ ? R s R $t${$? B ej P t I Z s R I R}js9s I Zt }jst s s B B {B $ tIB sK tBR jZ9 8 { I s jBR P { BR js $%$R sR I js I$js s{$? Bt I j $ 8}B q sR j t%? B I js 4B s 8? sR {tBj? B ${s8 t s%st9sIs s RZ jj sIs sj }Zt B I I R $tB ? R s Ys JZ IsIB ks BARBj s IsIsR jsR I? {sIsR stR{Z $IsR I RI RZ jst9s8$ t B =ts Z s I sj 8s t$ ZI JZ$ js $8} BAsAj } R$R t{$s I Zt {Zs j t sj 7Z B} s $%$IsI st jsR tB ${$sR P t R s Zts As sjjs s{s {$Is s }B ` 8}jB d( sK tBR jZ9 I I$R st{$s R 8? t$8s q stR{Z $IBR ks I$ 9 sK tBR I RI js {Bt $ tIs j t%? B I B}sR Z B ? I t R JZ $ ? s t j 8 `B I jBR {sRBR B BR d( sK tBR I %$s` 5]? B8B }Z I } BjBt s R Zts Z s t sj R {BtI${$Bt R2 qs8A$? t j st $8} $B sj? s{ ${B I js 3 I s{$? Bt t j Zt$% RB $8s $ts $B I 7 s q , I A sP Bt s j } BAj 8s I jsR {B8Zt${s{$Bt R s js s I$R st{$s _s s {BB I$ts jsR 8$R$Bt R I -}jB s{$? Bt I j et } $R k I B sR {BjBRsj R sR Bts% R I A ? s I$R}Bt I Zt $8} BAsAj R$R 8s I R$t{ Bt$9s{$? Bt I jB` R ej }jst s I jBR R$8$BR {BtR $ Zk Zt }Zt B I $t4 -$? Bt t js {$t 8s B sP? s I j ? t B ZtB I
jBR R{sRBR hj8 R IBtI R sAB Ist jBR P { BR js $%$R sR I js I$js s{$? Bt I j $ 8}B =ts ts% R}s{$sj RZ {s js ? s tB{Y $tht$ s qskjB j {B8stIst I js 8$R$? Bt $R s RZR Z ?j $8sR $8} R$Bt R t RZ I$s $B I ts% s{$? Bt st R I RZ8$ R t j js B RZ K tB I js Y$A ts{$? BtU R $R 8 R R ks t j R}s{$B } BPZtIB I RI RZ }s $Is I js q$ s t d 1 NBR jB` R I js ts% $tI${st JZ js q$ s Ys t% ` {$IB ZtBR (( sK tBR =t RZj sIB JZ } BIZ{ Zts j$ s {BtPZR$? Bt sZtJZ {B8}j s8 t j? B ${B R ? Zt jBR {? stBt R js $%$R sR eR P? s{$j I IZ{$ js % jB{$IsI {Bt JZ js ts% R sj `s I js q$ s {Bt R s 8? t$8s $tPB 8s{$? Bt * `s8BR sj
© Los autores, 2001; © Edicions UPC, 2001.
-
* $t Bt s e$tR $t
]ZsI B E 1 i js $%$IsI R} {$sjU RBA $ 8}BR jBt $ ZI R k 8sRsR Ns B ? s I js js $%$IsI R} {$sj Ys } B8B%$IB Zts I jsR stI R %BjZ{$Bt R t P? R${sU I B{s j {s ? s{ sARBjZ B I {Bt{ } BR {B8B $ 8}B jBt $ ZI k 8sRs h 8 T 8 t s s$ sIBR t jBR {$ t ? h{BR I RI jBR $ 8}BR I psj$j B k W b Bt k B B s sj BAR %sIB Zt }s} j s{ $%B t js -} $8 t s{$? Bt
]Bt s{{$? Bt I jBt $ ZI RU
js jBt $ ZI I Zt {Z }B R 8? s-$8s t j R$R 8s I P t{$s t JZ ? R R t{Z t s t }BRB NBt $ ZI ) NBt $ ZI t }BRB >d wz jB{$IsI t R$R 8sR>z jB{$IsI I js jZ9D H@> Ns jBt $ ZI I Zt {Z }B -} $8 t s Zts {Bt s{{$? Bt t js I$ {{$? Bt I j 8B%$8$ t B 8? sR tB sAj {Zst B 8? sR ? s}$Is R s RZ % jB{$IsI VR? R$ t tZ R BR {$ jBR {Bt s8$tsIBR JZ Is s s? Zt R}s{$B }s s $8s $ts s Zts A Z`s RBA %BjstIB js {$ZIsI t tB{Y R I jZts jj ts }BI ? s8BR s% t Z s JZ? $}B I R{BAs ZRs I I$R K tB {j? sR${B B P Z B I Zts {tBjB ? s s%st9sIsU Zts A Z`s {j? sR${s R Z$ ? s I R s{stIB }B RZ } {Zj$s % R $8 t s 8$ t sR JZ Zts A Z`s js $%$R s BP { ? s Zts R$jZ s 8BI? j${s JZ Ys ? s jsR I j${$sR I {ZsjJZ$ % tI IB I } BIZ{ BR I$ ? ${BR
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
1
j $t %sjB I $ 8}B {B8} tI$IB t IBR RZ{ RBR BAR T %sIBR t Zt 8$R8B jZ s {$A j tB8A I $ 8}B } B}$B _s s {ZsjJZ$ BAR %sIB }s s j JZ s8ABR RZ{ RBR R 8st$h R t t jZ s R I$R $t BR R ? Zt RZ R$R 8s I P T t{$s j $t %sjB I $ 8}B stR{Z $IB t s8ABR R R$ 8} RZ} $B sj $ 8}B } B}$B q$ 8}B )
*$js s{$? Bt I j $ 8}BU
>d
wz jB{$IsI t s8ABR R$R 8sR>z jB{$IsI I js jZ9D H@>
q$ 8}B } B}$B
y8s $t 8BR JZ Zt {BR8BtsZ s I {$I }Bt PZ 9sR B8stIB Zts A % R$ R s s AB IB I Zts ts% R}s{$sj JZ R sj `s I js q$ s s Zts % jB{$IsI } ? B-$8s s js I js jZ9 ( { NBR n( 8$tZ BR I R$ R s 8 I$IBR }B jBR jB` R I js ts% R % ? st } BjBt sIBR s dd 1 YB sR I IZ s{$? Bt t j {Bt Bj { t sj I js 8$R$? Bt t q$ s =t R Z$8$ t B R I Zt %Z jB R}s{$sj I R sR {s s{ ? R ${sR RZj s ? s } ? s{ ${s8 t $t%$sAj
VZ8 t B I js 8sRsU s8A$? t js 8sRs $t {$sj I Zt {Z }B -} $8 t s Zts %s $s{$? Bt I s{Z IB {Bt js js $%$IsI R} {$sj =t {Z }B }BR Zts 8sRs 8? t$8s t R sIB I }BRBU 5Zt } JZ K tB {YsR{B }s s jBR s8st R I j I }B 2 sRs )
>d
wz jB{$IsI t s8ABR R$R 8sR>z jB{$IsI I js jZ9D H@>
sRs t }BRB
© Los autores, 2001; © Edicions UPC, 2001.
1 M
* $t Bt s e$tR $t
3$ E Ns }s sIB`s I jBR 8 jBRU B {? B8B {BtR %s 8? sR `B% t JZ Z Y 8stB j { B js s s I {B8} BAs {Z? st } ? B-$8B R R %sjB sj I js % jB{$IsI I js jZ9 et js tB% js JZ $tR}$ ? B j hj8
ej }jst s I jBR R$8$BR >Ns }jstr I R R$t R
d EnH I j P st{? R _$
BZjj R }jst s ks js BI$R s I =j$R R ? BZ k RZR IBR s{B8}sK tst R JZ$ t R t j sK tB 1x(( }s t I js q$ s Z8AB s js I$R st R jjs j ZR t js {BtR js{$? Bt I ! $? Bt
Ns ts% $t%$ s} tsR 1 sK tBR t {B jBR n(( sK tBR jZ9 JZ R }s st tZ R B 8ZtIB I js R jjs j ZR
@n
et }sjsA sR I j } BP RB Vt jj ZtB I jBR 8$ 8A BR I js -} I${$? BtU
"p s{$sR s RZR {BY R } P {{$BtsIBR k s 8? 8 {sA j YBtB I YsA R$IB JZ$ t jBR Ys }Z R B s }Zt B R s ts% }Z I I R}js9s R }B j R}s{$B s js 8skB % jB{$IsI JZ }Z Is ZR I $8s $ts R }s s Zt {Z }B 8s $sj R I {$ s js % jB{$IsI I js jZ9 8 tBR }R$jBt > H +Z$ B I {$ JZ }Z I s{ {? s R j {Bt R? BjB Zts I$P t{$s I Zts {st $IsI $tht$ R$8sj I j B I t I Zts 8$j8$jjBt? R$8s R$ ZR I JZ$ " ! B sR} { B stsj$9sIB t js 8s $R sj tB% js R j $ 8B {Bt JZ 4Zk j $ 8}B t js ts% k t js q$ sU jBR 1 sK tBR I %$s` } R t st Zt t% ` {$8$ t B I R R$ jBR k 8 I$B }s s tZ R B }jst s p st }s I j %$s` R $t%$ t s{ j s js ts% I RI j }BRB YsR s s} tsR sj{st9s js % jB{$IsI I js jZ9 sR? {B8B t I Rs{ j s ? R s YsR s j }BRB s RZ jj sIs s j ZR
et js R {Z js
i RB sj }jst s I jBR R$8$BR >
t s Y Y _jst BP Y V} R d E H R t%? s Ns I$js s{$? Bt I j $ 8}B sA Zts
Zts ts% I R{s t sZ-$j$B I js } $8 s -} I${$? Bt R $ I $t B st RU
s jBR R $R 8 R R I j jst9s8$ t B I js } $8 s ts% BIB }s {? s t
B I t 7$ t js q$ s YsA? st stR{Z $IB ks (( sK tBR 5JZ$? t k {Bt JZ? BA` $%B I {$I t%$s Zts 8$R$? Bt I R{s 2 5_B JZ? s jBR (( sK tBR k tB s jBR x(( }B ` 8}jB2 V? Zt 8? sR 5{? B8B R }BR$Aj JZ sj ZtBR 8$ 8A BR I js 8$R$? Bt I R{s {BtB{$ st } RBtsj8 t s qskjB 2
eR $8s{$Bt R {$ t R I js I$R st{$s s js RZ} $ st B`s j ZR ! $Bt$R Ist Zt %sjB I ;EE sK tBR jZ9 dn
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }sÂ&#x201E;s %$s`Â&#x201A;Â&#x201E;BR IÂ&#x201A;j $Â&#x201A;8}B
3$ E M VZtJZÂ&#x201A; Â&#x201A;j YB8AÂ&#x201E;Â&#x201A; RÂ&#x201A; %$R s IÂ&#x201A; RÂ&#x201A;Is YB8AÂ&#x201E;Â&#x201A; RÂ&#x201A; JZÂ&#x201A;Is 3B B Â&#x201E;s8sR IÂ&#x201A;j {j? sR${B hj8Â&#x201A; ej }jstÂ&#x201A; s IÂ&#x201A; jBR R$8$BR >_jstÂ&#x201A; BP YÂ&#x201A; V}Â&#x201A;R d EMH
Š Los autores, 2001; Š Edicions UPC, 2001.
n((
* $t Bt s e$tR $t
i sj8 t st %$ `BR s8$ BR _B B B jsIB }s { $8} BAsAj JZ I A$IB s Zts I$RPZt{$? Bt 8}B sj js R ZtIs ts% %Z j%s s } {$}$ s R RBA j 8$R8B }Zt B I js q$ s k t js 8$R8s ? }B{s JZ js } $8 s Ns j? B ${s I I 8$tsIBR s Z8 t BR I B sR } j? {ZjsR I j ? t B JZ Is {$ s8 t t tT I${YB I RI js } R} { $%s I js js $%$IsI R} {$sj jsI iZtt >d M1H }B ` 8}jB { s Zt PZ Z B } ? B-$8B IBtI js $t t$ ? s Ys jj sIB s I Rs Bjjs stI B$I R st RBhR ${sT IBR jBR jjs8sIBR W -ZRTE B }j${st R JZ s} tsR RZj st I$R $t Z$Aj R I jBR R R YZ8stBR NBR }j${st R R? BjB %$% t ; sK tBR }s s %$ s JZ }Z Ist jj s s I Rs Bjjs RZR } B}$sR 8BT {$Bt R 7$t 8As B sj htsj I js {$t s s k j Z ?j $8B I jBR }j${st R YZ$IBR sh 8sU "Y %$R B s s{s ts% R t jjs8sR 8? sR sjj? s I ! $? Bt" eR I$P? {$j R sAj { js I$R st{$s sj s ! $? Bt ]B8B BIsR jsR {BtR js{$Bt R {BtR $ Zk Zts } R t s{$? Bt s A$ s $s I BA` BR R$ ZsIBR s I$R $t sR I$R st{$sR Ns I$R st{$s s RZR R jjsR 8? sR A $jjst R k {BtB{$IsR }Z I {$P s R t tBR jZ9 wVjt$js8 B 6 ! $Bt$RD NBR W -ZRTE ;EE sK tBR jZ9 w j ZR B ! $Bt$RD k d E(( sK I A ? st YsA { Z9sIB Rs I$R st{$s t 8 tBR I {Zs B sK tBR q t$ tIB } R t j j? 8$ I % jB{$IsI R $8}Z R B }B js jZ9 jBR {Zs B sK tBR I %$s` I A ? st {B R}BtI sj $ 8}B } B}$B s $8}BR$Aj {B Rs I$R st{$s R I {$ sj $ 8}B 8 I$IB t js ts% wI B s PB 8s RZj s ? 8}j stIB R? BjB ; sK tBRU js % jB{$IsI 8 I$s I j %$s` R ? s RZ} $B s js I js jZ9D 7Z}Bt$ tIB Zts I$R st{$s 8 I$s I ZtBR d ((( sK tBR jZ9 R P? s{$j R $8s js P {Ys t js JZ }s $ Bt I ! $? BtU s} B-$8sIs8 t t j R$ jB g7B } Rs 7 ? Zt }s { jBR R R YZ8stBR YsA? st I R{ZA$ B ks j %Z jB R}s{$sj t ? }B{sR 8Zk st $B R s jsR I j 7}Z t$, NsR {BtR {Z t{$sR RBt R$8}j 8 t s sIB sRU B A$ t jBR W -ZRTE %$% t 8? sR I ; sK tBR Z gB`B JZ $IB j { B Ys{ R$ jBR JZ R R{BtI t t tBRB BR V? Zt } B jB $ t 7Z} 8st JZ I A sP Bt s j B I { Z9s E sjs-$sR YsR s jj s s tZ R B 8B B 8ZtIB s9Zj NBR R sK tBR I %$s` 8 I$IBR t j $t $B I js I$8$tZ s {? s}RZjs R}s{$sj 8Bt st js P {Ys I jst9s8$ t B s js } Y$R B $sU 7Z} 8st }s $? B I $} Bt Ys{ ZtBR d( 8$jjBt R I sK tBR ? sR $t{ ? Aj R$ {sA R j s Z8 t B I ytI } tI t{ *sk >d EHU jBR YBR $j R sj$ t? tsR } B%$ t t I Zt 8B B }jst s 8B $AZtIB s ( ((( 8$jjBt R I sK tBR jZ9 +Z$9? sR Yskst t{Bt sIB Zt s s`B sZtJZ jB 8? sR }BR$Aj R s JZ j Z$Bt$R s RZP s I Zt stZ8 $R8B sjB}st k JZ st B j I t {B8B ( ((( 8$jjBt R I sK tBR jZ9U gtB -$R t$t ? Zt 8 {st$R8B P? R${s8 t }BR$Aj JZ } 8$ s tB I sjj I JZ sj { Z9s sj I$R st{$s t j $ 8}B I %$Is I j Zt$% RB wFZt B sj } JZ K I$R st{$s RBA }sRs jsR I$8 tR$Bt R R $8sIsR }s s tZ R B Zt$% RB D =t sR} { B R} {$sj8 t 8s {sAj I js I$js s{$? Bt I j $ 8}B R RZ ZRB {B8B 8? sJZ$ts I j $ 8}B P? R${s8 t %$sAj U sj stIB j $ 8B {Bt JZ 4Zk j $ 8}B Zt sR BtsZ s }BI ? s %$s`s sj PZ Z B I js q$ s _BI ? s {B8} BAs R$ tZ R BR 8B R RBA js I sIs{$? Bt I j }jst s RBt $tPZtIsIBR }BI ? s {BtB{ JZ$9? sR s jBR t$ BR I RZR A$9t$ BR $t{jZRB j {Z RB R Z$IB }B js Y$R B $s 8$j sK tBR I R}Z? R I RZ } B}$B ts{$8$ t B 7$t 8As B RZ -$R t{$s R % ? s {BthtsIs s Rs ? }B{s WB -$R t 8 {st$R8BR JZ } 8$ st $t% $ j 4Z`B I j $ 8}BU j RB sj } R t R $8}BR$Aj 7 s s }Z R I Zt %$s` Zt$I$ {{$Btsj IBtI R? BjB j PZ Z B R s{{ R$Aj eR s PsR{$tst $I s Ys R$IB sAB IsIs }B I$R $t BR js BR {B8B qY 3$ 9p sjI ]Bt s{ $Bt >d n(H I $j R F Z B t qY q$8 e-} RR >d n1H I Ws 7{Ys{Yt et ? R Zt YB8A {BtR$ Z %$s`s sj PZ Z B R$t t$t ? Zt R$R 8s I } B}ZjR$? Bt wg $t{jZRB R$t sj `s R I js q$ s D ZRstIB }s s jjB ZtBR skBR 8$R $BRBR JZ Ys{ t %$A s jBR s ? B8BR I RZ {Z }B
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
n(d
s Zts % jB{$IsI } ? B-$8s s js I js jZ9@; NBR P { BR js $%$R sR I js I$js s{$? Bt I j $ 8}B Yst {BtR $ Z$IB js AsR {$ t ? h{s }s s -}jB s j I R $tB htsj I tZ R B Zt$% RB =t ` 8}jB tB sAj jB t{Bt s8BR t qsZ { B >qsZ B d (H I _BZj VtI RBtU jBR $}Zjst R I Zts ts% JZ R I R}js9s s Zts % jB{$IsI - 8s % t j $ 8}B {Bt js R t RZ $t $B ej Zt$% RB %BjZ{$Bts st ? s}$Is8 t JZ s{sAs }B I t RZ -}stR$? Bt {Bjs}Rs k Is jZ s s Zt tZ %B $ st 5*? BtI %$% t }Z R R BR } $%$j $sIBR BAR %sIB R2 qs8A$? t ej 8ZtIB sj htsj I j $ 8}B I 3 I $, _BYj ts s js BI$R s I Zts -$ Zs {BjBt$s YZ8sts JZ sR$R sj ht I j Zt$% RB NBR {Z $BRBR t R t R sIB I }jsR8s JZ YsA$ st j $t $B I jsR R jjsR tP sR{sIBR t RZR $ ? st${sR jZ{YsR } B%B{st js s{ j s{$? Bt I j R$R 8s RBjs IBtI YsA$ s I${Ys {BjBt$s YsR s % jB{$IsI R js $%$R sR ej 4Z`B I j $ 8}B }s { { Rs t R 8B B $t{? Bt I j Zt$% RB 8$ t sR BIB t% ` { s Zt $ 8B P t? ${B t j R}s{$B - $B WB R {BtB{ t$t ? Zt {Bt s ` 8}jB JZ {Z R $Bt jsR R$R I js js $%$IsI Rs j$8$ s{$? Bt I j 8B%$8$ t B I jBR {Z }BR 8s $sj R s % jB{$IsI R $tP $B R s js I js jZ9 eR sR} { B Ys R$IB I j$A sIs8 t $ tB sIB }B sj ZtBR R{ $ B R k Z$Bt$R sR IstIB }$ s {Z $BR? R$8sR R$ Zs{$Bt R et "Ns As sjjs" >qY s j d M H ZtB I jBR } $8 BR }$RBI$BR I js Rs s j %$R$%s 7 s q ,U js tZ %s t s{$? Bt I R{ZA $8BR js I tB8$tsIs 8st$BA s _${s I F stT NZ{ _${s I R BAR JZ$sIB {Bt j 7 s s9 js st $ Zs ts% I j {s}$ ? st } I$Is IZ st sK tBR sR js {? j A As sjjs I s-$s {Bt s PZ 9sR P t $ I$st Zt {Bt BjsIB 8 t sj _${s I R BAj$ sIB s %$%$ js As sjjs s AB IB I j 7 s s9 _s s AZ js js 8A R $Is I j et } $R _${s I $8}ZjRs }B Zt A % $tR st RZ ts% s Zts % jB{$IsI 8skB JZ js I js jZ9 ]B8B RZj sIB js ts% }s { R s s js % 9 t IBR R$ $BR eR s Y? sA$j 8st$BA s I R s $s R ? s %? sj$Is R$ js ts% }ZI$ s RBA }sRs jBR skBR jZ8$tBRBR 8$ $IBR t Zt $tR st st $B %$s`stIB }s s jjB 8? sR ? s}$IB JZ js jZ9 VZtJZ RsA 8BR JZ tsIs }Z I %$s`s 8? sR ? s}$IB JZ js jZ9 js {Z $BRs 8st$BA s _${s I RZ $ B s $t Rst {Z R $? BtU 5{? B8B R ? s js %$R$? Bt I RI j }Z t I 8stIB I j et } $R I Zts ts% JZ R I R}js9s 8? sR ? s}$IB JZ js jZ92 7Z $8s t R % ? s s8A$? t IZ}j${sIs {B8B js I j 7 s s9 +Z$9? sR js $8s t JZ R 8Z R s s js $}Zjs{$? Bt I j et } $R tB R s 8? sR JZ Zt 8BRs${B I $8? s t R BA t$IsR 8 I$st R tRB R s s%? R I j {Bt{Z $IB RZA R}s{$B {Z RB Z $j$9sIB }B jBR Z$Bt$R sR I js R $ }s s } } s RZR {B8Zt${s{$Bt R RZ} jZ8? t${sR ! B ` 8}jB I {tBjB ? s JZ Ys % t{$IB j j? 8$ I js % jB{$IsI I js jZ9 R 8Z R s t _jst s } BY$A$IB >3B A$II t _jst d xEH IBtI js YZ8st$IsI }s { YsA I Rs BjjsIB j %$s` RZ} jZ8? t${B t j sK tB 11(( et R? BjB Zt sK tB js $}Zjs{$? Bt I j ] Z{ B I jBR _jst sR =t$IBR ]x * sj{st9s j I$R st R$R 8s }jst s $B s }s { - sK tB JZ Zts ts% st % jB9 Z%$ s } BAj 8sR }s s sj{st9s js Vj s$ yzdx _BI ? I$R st{$s I R Z $IsI I dE( 8$jjBt R I ,8 JZ t { R$ s }s s R{s}s I js $ ? st${s -}jBR$? Bt I jBR 1(( s{ B R 8BtZ{j s R I j }jst s sj k {B8B R 8Z R s sj htsj I j hj8 Ns jZ9 t { R$ s }B{B 8? sR I M 8$tZ BR }s s % t{ Rs I$R st{$s 5_B JZ? Zts ts% JZ }Z I RZ} s js % jB{$IsI I js jZ9 $t%$ 1; YB sR t {B js2 ej {Z }B YZ8stB tB }Z I R -}Z R B s j %sIsR PsR R I s{ j s{$? Bt V? Zt Zts ts% R}s{$sj I$R K tsIs }s s sj{st9s % jB{$IsI R js $%$R sR t { R$ s ? s Zt $ 8}B {BtR$I sAj }s s s{ j s I PB 8s 8BI sIs * Y {YB R? BjB }s s sj{st9s Zts % jB{$IsI I ( d{ Zt I? {$8B I js % jB{$IsI I js jZ9
* Y {YB j ? s}$IB 8B%$8$ t B $tIZ{$IB t jBR s ? B8BR I RZ B st$R8B I A ? s } B%B{s Zt sZ8 t B I 8} s Z s st - 8B JZ s{sAs ? s {Bt RZ %$Is dx Ns I$R st{$s s js R jjs Vj s$ R I ZtBR dE sK tBR jZ9 d;
© Los autores, 2001; © Edicions UPC, 2001.
n(1
* $t Bt s e$tR $t
}s $ tIB I j }BRB k s{ j stIB s d t { R$ s ? s ZtBR nx I? sR I %$s` et R $ 8}B js ts% YsA ? s {B $IB ZtBR x d(@n 8 R I {$ Zts E % { R jsR I$8 tR$Bt R I j R$R 8s RBjs wI RI j 7Bj s js B ? A$ s I _jZ ? BtD eR RZj sIB s $h{s js $I s I JZ tB R }BR$Aj js ts% s{$? Bt t {BtI${$Bt R js $%$R sR t j $t $B I Zt R$R 8s }jst s $B -{ } B }s s RBtIsR tB $}ZjsIsR NBR P { BR I js I$js s{$? Bt I j $ 8}B }s { t R -{jZR$%BR I jBR %$s` R $t R js R Ns % jB{$IsI I j { Z{ B ]x * {Bt sR s {Bt js I j }js $jjB %Bjst I js 8s $R sj =j $8? s Z8 s js q$ s >qY *sk Y es Y 7 BBI 7 $jj d xdH JZ $t%$ x 8 R R t {B jBR ;(( 8$jjBt R I ,8 JZ R }s st js q$ s I RZ 8ZtIB ts sjdE Ns % jB{$IsI 8 I$s I js ts% R I dd(!((( ,8>Y Zts {$P s 8BI R s st R? BjB R % { R js % jB{$IsI I R{s} I js q$ s k {B8}s sAj s js % jB{$IsI JZ }Z I sj{st9s Zts ts% sj * RI js R s{$? Bt I js B ? s I js js $%$IsI R} {$sj R Yst sj9sIB %B{ R {Bt s $sR s s{ } s js % jB{$IsI I js jZ9 {B8B j? 8$ ts Z sj I tZ R B Zt$% RB <s{ sj ZtBR sK tBR s8}B{B R tsj? sAs8BR tB Ys{ { ? s JZ jBR s%$Bt R RZ} s ? st sj ? Zt I? s js As s I j RBt$IB w{B8B ks R K st B $t{jZRB R IZIsAs I JZ j YB8A }ZI$ s sj9s R sj ? Zt I? s t jBR {$ jBR s AB IB I 8$ sj ? Zt $t t$B 8 {? st${BD eR $8}B st Rsj s JZ js % jB{$IsI I j RBt$IB {BtR $ Zk Zt j? ? {t${B WB Ysk tsIs t jsR j k R I js P? R${s JZ $8}$Is RZ} s jB _B {Bt s js % jB{$IsI I js jZ9 tB 4 `s jBR j? 8$ R I tZ R s {tBjB ? s R$tB jBR I js } B}$s ts Z sj 9s I j Zt$% RB 7$ Zts ts% $8s $ts $s R sj `s s I js q$ s s st % jB{$IsI s{ j stIB } B R$%s8 t YsR s s{ {sR s js % jB{$IsI I js jZ9 RZ {BtRZ8B t ? ${B $ ? s t sZ8 t BU t %$ ZI I jBR P { BR js $%$R sR js 8sRs I js ts% sZ8 t s ? s {Bt js % jB{$IsI }B jB JZ JZ $ ? s Zts t ? s sI${$Btsj }s s s{ j s Zts 8sRs 8skB Vj sj{st9s js % jB{$IsI I js jZ9 jBR P { BR I R{ $ BR R s{ t ? Zst YsR s Zt }Zt B I Z} Z s ej ? 8$tB {B8? Zt s BIsR jsR %s $sAj R P? R${sR Bt I j 8B%$8$ t B R t js $%$IsI R} {$sj w]ZsI B E 1D R stZjsU js jBt $ ZI t js I$ {{$? B ts tZjs j $ 8}B R I $ t k R JZ$ Zts t ? s $tht$ s }s s {B8} tRs j I s8? s ${B sZ8 t B I js 8sRs I js ts% JZ Ys sj{st9sIB j$ sj8 t Zt %sjB $tht$ Bd *$% RsR s9sR I j Zt$% RB q , {B8B jBR 9 s $stBR I js R $ B $ $tsj jBR - sK tBR YsA$ st R I js tZA s i tts I 7 s q ,U js tZ %s t s{$? Bt B jsR t $IsI R PB ? Bt${sR I js R $ 7 s q ,U zBks >d xT H I A ? st -} $8 t s Rs I$js s{$? Bt - 8s I j $ 8}B sj I R}js9s R s js % jB{$IsI I js jZ9U R ? st R $ BR I js %BjZ{$? Bt I j Zt$% RB YsR s j htsj I RZR I? sR t Zt $ 8}B tZjB eR {$ B JZ tB R {BtB{ t jBR j? 8$ R I jsR B ? sR P? R${sR s{ Zsj R +Z$9? s -$R s sj ? Zt } $t{$}$B BIs%? s I R{BtB{$IB JZ } 8$ s As`B {BtI${$Bt R 8Zk }s ${Zjs R jBR %$s` R RZ} jZ8? t${BR * R sR? k } R s RZ $8} BAsA$j$IsI }BtI ? s t { $R$R tZ R sR 8? sR } BPZtIsR {Bt{ }{$Bt R RBA js ts Z sj 9s I j Zt$% RB t j JZ %$%$8BR Vj{st9s js % jB{$IsI I js jZ9 RZ}Bt BIB Zt B I RI j }Zt B I %$R s P? R${B 7Z} s js Zts JZ$8 s Zt RZ K tB $8}BR$Aj VZtJZ R$ 8} }Z I sj$9s R j ` {${$B 8 t sj I P stJZ s R j? 8$ U 8sRs jBt $ ZI k $ 8}B R {Bt%$ t t Bt{ R t {st $IsI R $8s $ts $sR NBR
WB R {BtB{ t$t ? Zt }jst s YsA$ sIB s Rs I$R st{$s I js q$ s ej 7Bj I$R s I js q$ s ZtBR dx( 8$jjBt R I ,8 V Zts I$R st{$s {B8B js {$ sIs t js } j? {Zjs R t{Z t st {Z $B z tZR k s ej sI$B 8 I$B I js B ? A$ s I F? Z}$ JZ Is 8? sR sjj? s I jBR ;(( 8$jjBt R I ,8 d qsj k {B8B 3 I $, _BYj ts s t ej 8ZtIB sj htsj I j $ 8}B Zts ts% JZ R s{ {s s sj j? 8$ js $%$R s tB jj s ? s s sj{st9s js % jB{$IsI I js jZ9 _B{B st R js $t tRs s% IsI } B%B{s ? s RZ {Bjs}RB s s Z` B t B dE
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
n(n
{$ t ? h{BR Yst RZ $IB IBR $t } s{$Bt R }BR$Aj R s R RZj sIB * PB 8s B BIB-s j {s ? s{ $8s $ts $B I I${YsR 8s t$ ZI R R $t } s {B8B Zts } Z As I js $8}BR$A$j$IsI I j %$s` RZ} jZ8? t${B 5+Z? R t $IB $ t Zt $ 8}B B Zts 8sRs $8s $ts $s2 =ts % 9 8? sR j Zt$% RB sZ B$8}Bt Zt R % B j? 8$ I % jB{$IsI R IsIB }B j I R}js9s8$ t B I js jZ9 t j %s{? B WB BAR st Zts 8$tB ? s I {$ t ? h{BR RBR $ t JZ jBR t? Z8 BR {B8}j `BR sj$R$R I {$ {Z$ BR I RBt s 8 tZIB ZRsIBR t P? R${s {B8B 8st$}ZjsIB R sj A s${BR w t j st? {B $ t sj ts }B ` 8}jBD JZ I R 8AB{st t RBjZ{$Bt R sj R 5_BI ? st R sR % jB{$IsI R {B8}j `sR {BtR $ Z$ RBjZ{$Bt R sj R t B B Zt$% RB2 =ts } Zt s {Zks R}Z R s R{s}s I jBR j? 8$ R I js P? R${s k JZ }s { - tI R sj R$tZBRB IB8$t$B 8 sP? R${B *sIs js }s t $8}BR$A$j$IsI I s{ j s Zts }s ? {Zjs YsR s % jB{$IsI R RZ} $B R s js jZ9 sj ZtBR {$ t ? h{BR Yst RZ $IB js -$R t{$s I Zt {$ B $}B I }s ? {ZjsR I tB8$tsIsR sJZ$Bt R }B j P? R${B p sjI 3 $tA t d E { sIsR t } B{ RBR BIs%? s I R{BtB{$IBR JZ R I R}js9s ? st R$ 8} s 8skB % jB{$IsI JZ js jZ9 R$t }BI tZt{s sj{st9s % jB{$IsI R RZAT jZ8? t${sR ej Zt$% RB R s ? s {B8}Z R B }B }s ? {ZjsR 8? sR ? s}$IsR JZ js jZ9 jBR sJZ$Bt R k }s ? {ZjsR {Bt% t{$Btsj R $t{$I t sj8 t I tB8$tsIsR s I$Bt R _ R s JZ js -$R t{$s I jBR sJZ$Bt R tB %$Bjs ? s jBR P { BR } I${YBR }B js B ? s I js js $%$IsI R} {$sj k } R s js } Bj$P s{$? Bt I 8BI jBR ? B ${BR RBA sj R }s ? {ZjsR %$ Zsj R t js j$ s Z s {$ t ? h{s R} {$sj$9sIs Zt s8}j$B R { B I P? R${BR }s { t {Ys9s jBR I }j tB NBR sJZ$Bt R I T A ? st } R t s Zts 8sRs $8s $ts $s VZtJZ j } BAj 8s PZtIs8 t sj {Bt I${YsR }s ? {ZjsR Y$}B ? ${sR Zs Is js{$? Bt I tZ %B {Bt js %$Bjs{$? Bt I js {sZRsj$IsI Ns js $%$IsI R Zts B ? s {sZRsjU } R sj %$I t Rsj B {Bt{ } Zsj $t BIZ{$IB }B P { BR {B8B js I$js s{$? Bt I j $ 8}B B j } $t{$}$B I R$8Zj st $IsI j B I t {sZRsT P { B tZt{s R $t%$ eRB I `s I R {$ B }s s }s ? {ZjsR sJZ$? Bt${sR _Bt s8BR Zt ` 8}jBU Zt }Bj${? s }s Zjjs Zts stJZ$js 9Bts R$I t{$sj =t %? stIsjB s 8sIB {Bt Zt I$R}BR$ $%B R} {$sj jst9s Zts }$ I s sJZ$? Bt${s w R I {$ Zts }$ I s JZ R 8Z % s 8skB % jB{$IsI JZ js jZ9D {Bt s Zts R s Zs * RI sj ZtBR R$R 8sR I P t{$s j }Bj${? s % ? s } $8 B P s 8 t s R js R s Zs }s s % }BR $B 8 t Zts 8stB jst9stIB js }$ I s@M NBR {Z $BRBR P { BR JZ }jst s js 8 s -$R t{$s I jBR sJZ$Bt R Yst R$IB - tRs8 t stsj$9sIBR PZtIs8 t sj8 t I RI js } R} { $%s I RZ {Bt -$? Bt {Bt js $t% R$? Bt I js 4 {Ys I j $ 8}B et sj ZtsR tB% jsR I j ? t B R Yst Z $j$9sIB sJZ$Bt R {B8B 8 {st$R8BR Z ? $j R }s s t%$s 8 tRs` R {BI$h{sIBR sj }sRsIB Ns { j A sIs tB% js ] BtB}s$Rs` I p B k tT PB I {BtR $ Zk Zt }s sI$ 8s tPB I } R t s js %$R$? Bt s}B{sj? } ${s I Zts q$ s PZ Z s d M IBtI js }BjZ{$? Bt 8 I$Bs8A$ t sj Ys I$ 98sIB jsR } BAsA$j$IsI R I RZ} %$% t{$s =t JZ$}B I {$ t ? h{BR $t t s t%$s 8 tRs` R I sj s sj }sRsIB Z $j$9stIB sJZ$Bt R } BIZ{$T IBR s }s $ I Zts PZ t I st $8Bt$Z B I $tI$B $t` t{$s JZ sj s j {Z RB I sj ZtBR s{Bt {$8$ t BR Y$R ? B ${BR ]B8B R j? B ${B j ZRB I sJZ$Bt R {B8B 8 {st$R8B }s s tT %$s 8 tRs` R sj }sRsIB B}s P Bt sj8 t {Bt j 8$R8B } BAj 8s I jBR %$s` R sj }sRsIBU js
et js tB% js Ns 4 {Ys I j $ 8}B >q$8 :R V Bb d dH RZ sZ B s $t V8$R ts s Zts RB } tI t Y$R B $s % IsI B jsA $t B 8}B sj JZ 8}$ 9s R I Rs Bjjs k 8$ts sj %? R ej } B s Bt$R s {BA s I jBR s-$R sR JZ jB jj %st s jZ s R IBtI tB I R s $ B8} {Bt RZR s8st R }s s ts8B s R jZ B I jjsR tRZ{$s jBR }js BR st R I YsA {B8$IB `Z% t { t jZ s I t% ` { dM
© Los autores, 2001; © Edicions UPC, 2001.
n(;
* $t Bt s e$tR $t
{ s{$? Bt I }s sIB`sR tPB I -}jB s jsR }B t{$sj R s}j${s{$Bt R I jBR sJZ$Bt R t B sR I RZR BA sR {B8B 7ZIs $B I R jjsR >qY 7 s R $t 7Y BZI d MHU t Zt PZ Z B 8B B sR { t ts R I sK tBR I -}stR$? Bt }B js psjs-$s {Bt% $Is t Zt % IsI B $8} $B sj? s{ ${B js YZ8st$IsI B8s {Bt s{ B {Bt js s R$%s s9s - s R I jBR +Zs t =t t{Z t B %$Bj t B JZ I R t{sI ts Zts - sK ts }js s }R? JZ${s t jBR YZ8stBR _s s Ys{ P t s jsR $tRsj%sAj R I$R st{$sR tPB I $t BIZ{ j Rsj B sJZ$? Bt${B 8 {st$R8B }B j JZ js 8s $s {Bt% t{$Btsj R stRPB 8s $tR st ? st s8 t t sJZ$? Bt${s Ns I$R{Bt $tZ$IsI t j } B{ RB I s{ j s{$? Bt Ys{ I$P? {$j t sZR t{$s I 8? sR Is BR {Z R $Bts j }BR$Aj P { B RBA jBR B st$RT ZjB 1D ! BR ` 8}jBR I j ZRB I I$R}BR$ $%BR sJZ$? Bt${BR t js {$ t{$s h{{$? Bt 8BR %$%BR w]s}? jBR t{Bt s8BR t ej }sjs{$B I js t$IsI >qY _sjs{ BP e t$ k d E H I BA 7Ysb IBtI Zts ts% sJZ$? Bt${s RZ {s j B{? stB I js tB{Y s n( ((({ B js t$sj s{ BR{B} >d E H I _$ R Vt YBtk IBtI Zts sR Bts% t ? $8 t RZ} jZ8? t${B {BtR $ Zk j R{ ts $B I js 8Z I Zt YB8A JZ } B R$%s8 t g `Z% t { YsR s s{sAs ts{$ tIB et ej 8ZtIB sj htsj I j $ 8}B I 3 I $, _BYj jsR - sK tsR { $s Z sR I }jsR8s JZ YsA$T st j $t $B I jsR R jjsR Z $j$9st RBhR ${sIBR 8 {st$R8BR I {B8Zt${s{$? Bt }s s Rsj%s jsR $tRBtIsAj R I$R st{$sR FZt B s jBR sJZ$Bt R R I R{ $A j ZRB I jBR tB 8 tBR {Bt B% $IBR }s R e_i {ZkB B $ t R 8Bt s s Zts }s sIB`s } B}Z R s }B e$tR $t k {BjsAB sIB R t d nx _ R s $8}ZjRs j ts{$8$ t B I js 8 {? st${s {Z? st ${s {Bt RZ {s s{ $9s{$? Bt I j P { B PB B j? { ${B e$tR $t {B8As $? B IZ s8 t j {s ? s{ } BAsA$j? R ${B I I${Ys B ? s Ns {? j A {$ s "*$BR tB `Z s s jBR IsIBR" 4 `s RZ h 8 B}BR${$? Bt s js jjs8sIs $t } s{$? Bt st${B {Z? st ${B } R t s Zts I$R $AZ{$? Bt I } BAsA$j$IsI I I ]B} tYs Z @ U Zt R$R 8s 8 {? R sIBR }BR$Aj R 7Z R sIB } {$RB I } tI I j BAR %sIB {Zks $t s{{$? Bt {Bt j R$R 8s R sj JZ ? R tB }Z I {BtR$I s R {Bt Zts -$R t{$s $tI } tI$ t ]B8B R}Z R s s js $t T } s{$? Bt I ]B} tYs Z e$tR $t k jBR P? R${BR _BIBjR,k k W iBR t }jst s Bt js R$ Z$ t }s sIB`sU $8s $t 8BR JZ Zt t? Z{j B s ? B8${B R R{$tI t IBR }s ? {ZjsR $I? t ${sR V8AsR }s ? {ZjsR }BR t Zts {$ s I$R $AZ{$? Bt I } BAsA$j$IsI I R sIBR JZ tB R sIZ{ s R sT IBR {Bt{ BR YsR s tB R 8 I$IsR {Bt } {$R$? Bt 7Z}Bt s8BR JZ R I `s {B Zts st I$R st{$s s s8AsR }s ? {ZjsR R$t R 8 I$IsR 7$ }sRsIB Zt $ 8}B R 8$I t jsR } B}$ IsI R I Zts I RsR }s ? {ZjsR 5JZ? B{Z $ ? s {Bt js B s2 =ts % 9 JZ j R sIB I js }s ? {Zjs Ys R$IB {js s8 t h`sIB }B j -} $8 t B j R sIB I js }s ? {Zjs I A JZ Is sZT B8? s ${s8 t } h`sIB t %$ ZI I jBR } $t{$}$BR P? R${BR I {BtR %s{$? Bt 7Z I$R $AZ{$? Bt I } BAsA$j$IsI R I R%st { 7 ? Zt e$tR $t k RZR {BjsAB sIB R Rs {Bt{jZR$? Bt } Z As JZ s8AsR }s ? {ZjsR I A? st }BR R Z ?t${B R sIB I RI Zt } $t{$}$B $t{jZRB st R I $t${$s jsR 8 I${$Bt R * B B 8BIB R$ k R Z%$ st jB RZh{$ t 8 t sj `sIsR I A ? s $tPB 8s $tR st ? st s8 t s I j RZj sIB I js 8 I${$? Bt {$ {ZtR st{$s JZ JZ $ ? s Zts {B8Zt$T {s{$? Bt s % jB{$IsI R RZ} jZ8? t${sR ej I As } 8st {$? B sA$ B IZ st n( sK tBR YsR s JZ t d E1 j P? R${B FBYt jj } B}ZRB Zts js{$? Bt JZ $t%BjZ{ sAs {st $IsI R 8 {? st${BT{Z? st ${sR JZ }BI? st R 8 I$IsR et PZt{$? Bt I j %sjB I ? R sR e$tR $t tI ? s s9? Bt B tB 3sj sAs R${BRD NBR Zt -} $8 t B }s s %sj$Is B PZ s js }s sIB`s e_i w$t${$sj R I jBR {$ sIBR P? -} $8 t BR RZ $IBR }B jj R jj %s Bt s {sAB t I$% RBR jsAB s B $BR IZ st jsR IBR I? {sIsR R$ Z$ t R Zk R} {$sj8 t jBR -} $8 t BR {BtIZ{$IBR }B Vjs$t VR} { t _s ? R
\
4
4
\ 4
\
@
_ R t sIs }B j P? R${B Ist? R k } 8$B WBA j W$ jR BY wdM xTd E1D t ]B8B y sj$s t d 1
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
n(x
% $ Bt RZj sIBR {Bt{jZk t RU e$tR $t R sAs JZ$%B{sIB 5]Z? sj R }Z R js {Bt{jZR$? Bt htsj I js }s sIB`s e_i2 ej {BtR tRB t sj s}Zt s s JZ js 8 {? st${s {Z? st ${s } I${ {Bt -s{ $ ZI j {B8}B s8$ t B I js 8s $s s R{sjs 8${ BR{? B}${s R$t $t%B{s t { Rs $s8 t j t%? B I $tPB 8s{$? Bt s % jB{$IsI RZ} jZ8? t${s WB -$R t } R} { $%sR I {B8Zt${s{$? Bt s % jB{$IsI R RZ} $B R s js I js jZ9 JZ } 8$ st js stR8$R$? Bt I $tPB 8s{$? Bt Ns sj s{$? Bt t {sZRsT P { B jB Ys{ $t%$sAj ej R t $IB {B8? Zt s}Zt s Ys{$s j } $t{$}$B I tB R }s sT A$j$IsIU }s ? {ZjsR JZ Yst R sIB } %$s8 t j$ sIsR 8 I$st Zts I 8$tsIs $t s{{$? Bt R$ Z t R$ tIB t {$ B R t $IB {B8}Bt t R I Zt Z ?t${B R$R 8s JZ R}BtI {Bt`Zt s8 t s $t s{{$Bt R }BR $B R yt% R $ s{$Bt R PZ Z sR I A ? st sYBtIs t js {Z R $? Bt Ns js $%$IsI R} {$sj tB {BtR $ Zk Zts B ? s {B $I$sts et {sRB {Bt s $B %$%$ ? s8BR t Zt 8ZtIB 8? s ${B {B8B j $8s $tsIB }B js }jZ8s I j sR BP? R${B p B ps8Bb wd (;Td EMD t RZR {Z t BR I I$%Zj s{$? Bt qB8},$tR t j }s? R I jsR 8s s%$jjsR > qB8},$tR $t GBtI jstI d n H IBtI Zt AstJZ B I R{ZA jsR -{ j t{$sR I js js $%$IsI t Zts {$ZIsI $8s $ts $s IBtI js % jB{$IsI I js jZ9 sIB} s j 8BI R B %sjB I ;( ,8>Y Ns I R{ $}{$? Bt I qB8},$tR {BtR $ Zk Zts {js s %$R$? Bt I Zt Zt$% RB IBtI jBR P { BR js $%$R sR PB 8s ? st }s I js } B}$s -} $ t{$s {B $I$stsU jBR {${j$R sR sIB} st Zts s}s $ t{$s stB 8sj8 t I j sIs t js I$ {{$? Bt I j 8B%$8$ t B P Z B I js {Bt s{{$? Bt I jBt $ ZI R et RZ $t t B }B BAR %s RZ t B tB I RI js } R} { $%s I Zt {${j$R s qB8},$tR I {$I RZA$ R s Zts A${${j sU I R{ZA t Bt{ R Zts {$ZIsI {B8}j s8 t I PB 8sIs IBtI jsR {sRsR } R t st }Z sR k % t stsR R {Y? R$8sRU g$8}BR$Aj JZ sj Zts } RBts }sR }B jjsR yt{jZRB js t JZ stR$ s }B js s{ s R 8Z R s I {$I$Is8 t 8? sR I j sIs 7Z jB` }s { YsA -} $8 t sIB sj ? Zt {Z $BRB P t? B8 tBU R Ys s sRsIB R} { B sj jB` I js R s{$? Bt I P B{s $j IBtI R I $ t s $t% R $ s Ns jj sIs I Zt t j } 8$ t sAjs I$? sjB B {Bt Zts - sK ts }s `sU Zt `B% t %$s` B k Zts st{$sts VJZ j s{BR Z8A sIB s P {Z t R %$s` R %$I t{$s j P { B I js I$js s{$? Bt I j $ 8}B t R 8ZtIB } {Zj$s Ns st{$sts RZj s R RZ } B}$s t$ s VZtJZ R sR $8}j${s{$Bt R I js B ? s I js js $%$IsI }Z Ist RZj s RB } tI t R }s s tZ R s -} $ t{$s ps8Bb tB tjBJZ {$? B sj I R{ $A$ st {Z $BRB }stB s8s WB Y$9B 8? sR JZ { K t$ R s Zt I sjjsIB st? sj$R$R I Zt RZ}Z R B 8ZtIB IBtI js % jB{$IsI I js jZ9 PZ s Zt j? 8$ {B $I$stB s{{ R$Aj NsR { s{$Bt R 8? sR % jB{ R JZ Ys I Rs BjjsIB js {tBjB ? s YZ8sts jBR {BY R R ? st BIs%? s j `BR I js % jB{$IsI {Bt JZ R I R}js9s js jZ9 WB RZj s RB } tI t JZ js B ? s I js js $%$IsI tB PZ s $t BIZ{$Is t j s ?8A$ B P? R${B YsR s } $t{$}$BR I j R$ jB =tB I jBR sR} { BR 8? sR {Bt B% $IBR I jsR $8}j${s{$Bt R I js js $%$IsI R} {$sj R js {Bt -$? Bt t js sj s{$? Bt I jBt $ ZI R 8sRsR k $ 8}BR k RZ P { B }B t{$sj t js hR$BjB ? s I jBR sR BtsZ sR * R{ $A? s8BR sj stsj$9s j js B I ps8Bb {? B8B Zt {Z }B RZP Zts {Bt s{{$? Bt t RZ jBt $ ZI R ? Zt js I$ {{$? Bt I j 8B%$8$ t B V jBR B`BR I Zt {${j$R s t j Zt$% RB $8s $ts $B I qB8},$tR jBR } s Bt R }s {? st - s? IBR I Zt {ZsI B I ej p {B {Bt R$jZ sR stB 8sj8 t R $j$9sIsR +Z$? t RsA R$ ej p {B t RZ $ttB%s{$? Bt s ? R ${s tB $tR}$ ? B jsR AsR R I js js $%$IsI R} {$sj 7$ js % jB{$IsI I js jZ9 PZ R Zt %sjB {B $I$stB j P? R${B iBA GBBI }BI ? s YsA t$IB Zts 8 `B {Bs sIs }s s Rsj$ I js 8As s9BRs R$ Zs{$? Bt t js JZ R t{Bt ? B R ? Zt Zts st? {IB s wI B $ t IZIBRBD JZ R j s $AZk U }s s %$ s Zts 8Zj s I ? sh{B }B YsA R Rsj sIB Zt R 8? sPB B t B`B $t t ? B
© Los autores, 2001; © Edicions UPC, 2001.
n(E
* $t Bt s e$tR $t
{Bt% t{ sj Zs I$s JZ I A$IB sj I R}js9s8$ t B *B}}j I js jZ9 YsA? s %$R B j R 8? sPB B % I ej I R}js9s8$ t B *B}}j R Zt {BtB{$IB P { B I js jZ9 pZs Is js{$? Bt {Bt js sj s{$? Bt I jsR P {Z t{$sR jZ8$tBRsR w j {BjB D {ZstIB js PZ t 8$RB s R s{ {s B R sj `s I j { } B VR? R$ Zts ts% t sk { B $s I s} B-$8s{$? Bt t%$s s I R jjBR jZ8$tBRBR I Zts I 8$tsIs P {Z t{$s jsR R K tsj R {$A$IsR } R t s ? st Zts P {Z t{$s 8skB wI R}js9s8$ t B tsj R I { sIsR R ? s 8 tB sj s9ZjD 7$ 8$RB k { } B R sj `s st js P {Z t{$s I jsR R K wI R}js9s8$ t B sj B`BD eR P { B R Ys {B8} BAsIB t jsR BAR %s{$Bt R I sjs-$sR 8B sR JZ } R t st $8}B st R % jB{$IsI R I { R$? BtU js jZ9 } B{ I t I sj R BA` BR { j R R } R t s Zt s{ t ZsIB I R}js9s8$ t B Ys{$s j B`B WB BAR st js % jB{$IsI t { Rs $s }s s JZ Zt Ys9 jZ8$tBRB I {BjB B`B R BAR % s js P {Z t{$s {B R}BtI$ t s js jZ9 % I R Zt }s { j R K tB GBBI I A$? B R 8Zj sIB {Bt s9? Bt }B -{ RB I ZtBR g; !E(( ,8>R 7 ? I % jB{$IsI 5+Z? %$I t{$sR -} $8 t sj R {B BAB st Rs }j? ksI I P { BR RB } tI t R } I${YBR }B js B ? s I js js $%$IsI R} {$sj2 ]Bt -{ }{$? Bt I jsR BtIsR j { B8s t? ${sR wjs jZ9D jBR {Z }BR 8s $sj R R I R}js9st s % jB{$IsI R 8Zk $tP $B R s { t j {Bt`Zt B I -} $ t{$sR {B $I$stsR JZ $ t t jZ s t tZ R B t B tB WB PZ YsR s js I? {sIs I jBR sK tBR ( {ZstIB I js 8stB I jB` R s ? B8${BR I } {$R$? Bt R }ZIB jj %s s {sAB Zts -} $ t{$s }s s {B8T } BAs j P { B I js I$js s{$? Bt I j $ 8}B ]Bt{ s8 t t B{ ZA I d d IBR P? R${BR tB s8 ${stBR FBR }Y ] <sP j k i${Ys I e s $t Z $j$9s Bt {Zs B jB` R s ? B8${BR I j !AR %s B $B Ws%sj I jBR eR sIBR =t$IBR }s s 8 I$ I${YB P { B ]s s Bt jBR jB` R s AB IB I Zt FZ8AB k RBA %Bjs Bt j jBAB ? sJZ B } $8 B Ys{$s j R k jZ B Ys{$s j B R *sIB JZ js % jB{$IsI I { Z{ B I Zt s%$? Bt {Bt% t{$Btsj I$R s 8Z{YB I js % jB{$IsI s js JZ R } B}s s js jZ9 js I$R B R$? Bt } I${Ys }s s jBR jB` R s RZ8s8 t } JZ K tsU s} tsR Zt 8${ BR ZtIB }B I? s I %Z jB sZtJZ RZh{$ t }s s R 8 I$Is }B js {tBjB ? s I js ? }B{s NsR I$P t{$sR BAR %sIsR t jBR %Z jBR Ys{$s j R k Ys{$s j B R R I A? st {B8B ks $tI${s s e$tR $t t d (x s JZ js } B}$s B s{$? Bt I js q$ s $tIZ{ s8A$? t Zts I$js s{$? Bt t j 4Z`B I j $ 8}B NBR RZj sIBR Zts % 9 j$8$tsIs js {Bt $AZ{$? Bt I A$Is s js B s{$? Bt R PZ Bt {Bt{jZk t RU js -} R$? Bt js $%$R s }s s js I$js s{$? Bt I j $ 8}B } I {? s Zt RZj sIB }j ts8 t {B8}s $Aj {Bt jsR BAR %s{$Bt R g s%B e$tR $t ! BR -} $8 t BR jj %sIBR s {sAB t jsAB s B $BR I P? R${s I }s ? {ZjsR Yst % jsIB s8A$? t {? B8B js 8sRs I sj ZtsR }s ? {ZjsR JZ R I R}js9st s st % jB{$IsI wjBR j { Bt R }B ` 8}jBD R 8Zk RZ} $B sj %sjB 8 I$IB t }BRB 7$t IZIs ZtB I jBR ` 8}jBR 8? sR PsR{$tst R %$t{ZjsIB s8A$? t sj s ?8A$ B I jsR jjs8sIsR }s ? {ZjsR j 8 t sj R R j I jBR 8ZBt R et j sK tB d nE jBR P? R${BR ] * VtI RBt k 7 p W II 8 k IsAst s {BtB{ js -$R t{$s I ZtsR tZ %sR }s ? {ZjsR jBR 8ZBt R { sIBR I PB 8s ts Z sj t js }s RZ} $B I js s 8? BRP s R 8 I$st {Bj$R$Bt R t jBR skBR {? BR8${BR k jBR {B8}Bt t R I
Ns $ Z}{$? Bt I js 8$tBjB ? s I js P? R${s I }s ? {ZjsR t js {$ t{$s h{{$? Bt Ys } B%B{sIB Bt 7 s q ,U js tZ %s {Z $BRsR R$ Zs{$Bt R et "7 s RY$} $t " >d nH }$RBI$B I js R $ I j %$R$? t s{$? Bt j et } $R s s{s t js AsR i 8j }s s {$A$ Zts j$8}$ 9s I As $Bt R RZ}Z R s8 t sIY $IBR sj PZR js` I js ts% {B8B RZj sIB I j %$s` s % jB{$IsI R RZ} jZ8? t${sR _ B jBR } B Bt R k t Z Bt R JZ {BtR $ Zk t jBR s ? B8BR I j 8s $sj I j JZ R ? s Y {YB j PZR js` RBt s8A$? t As $Bt R _B{B JZ Is ? s I j et } $R sR Zts j$8}$ 9s -YsZR $%s
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
n(
3$ E ej 8ZtIB R ? Zt jBR 8ZBt R
tZ R s } B}$s s 8? BRP s NBR 8ZBt R } R t st Zts %$Is 8 I$s P? 8 s I R$t ? stIBR t R? BjB Zts 8$t? ZR{Zjs P s{{$? Bt I R ZtIB 7$ Rs PZ R RZ IZ s{$? Bt sj tB tI ? st $ 8}B I {B js I$R st{$s JZ jBR R }s s I js RZ} h{$ R st R I I R$t s R {$ {ZtR st{$s JZ tB tI ? s tsIs I }s ${Zjs -{ } B JZ jBR 8ZBt R %$ t t R$ tIB I { sIBR t jBR jsAB s B $BR I$R 8$tsIBR }B I$P t R js $ ZI R I j }jst s * RI j }Zt B I %$R s I Zt BAR %sIB t q$ s w3$ E $9JZ$ IsD jBR 8ZBt R } R t st Zt jB`U RZ %$Is 8 I$s -} $8 t s Zts I$js s{$? Bt I j $ 8}B sj s{ {s R s js RZ} h{$ T R s st % jB{$IsI * RI j }Zt B I %$R s I Zt BAR %sIB JZ R 8B%$ s RBj$Is $s8 t {Bt jBR 8ZBt R w3$ E I {YsD ? R BR R t{Bt s ? st t }BRB }B jB JZ tB -} $8 tT s ? st t$t ? Zt sRB js $%$R s t j 4Z`B I j $ 8}BU RZ %$Is 8 I$s {B R}BtI ? s sj %sjB t }BRB 7$t 8As B js 8Bt sK ts JZ s}s t 8 t R s{ {s s jBR 8ZBt R s st % jB{$IsI RZP $ ? s Zts {Bt s{{$? Bt js $%$R s ]B8B j Ps{ B I {Bt s{{$? Bt I jBt $ ZI R R $I? t ${B sj I js I$js s{$? Bt I j $ 8}B j t? Z8 B I 8ZBt R JZ sj{st9s ? s js RZ} h{$ R R j 8$R8B I RI s8AsR P t{$sR
E x
Ws% R t s{$Btsj R $8} $BR sj? s{ ${BR
Ns -$R t{$s I }B t BRBR $8} $BR sj? s{ ${BR R Z{ Z sR 8$j$ s R k RB{$sj R JZ {Bt Bjst BIs Zts sjs-$s }s { I R%st { R {Bt js P s $j$IsI I Zt {sR $jjB I ts$} R st jsR $8}j${sT {$Bt R I js B ? s I js js $%$IsI ej 8 B $t t B I {B8Zt${s{$? Bt t j { t B sj? s{ ${B k jsR $Bt R } $P? ${sR Ys{$ tIB P t s Zt %s{? B I 8$j R I sK tBR jZ9 s}Zt s Ys{$s js $t%$sT A$j$IsI I Zt $8} $B {B8B j {BtRs sIB }B yRss{ VR$8B% t RZ {${jB I q st B $t${$sIB
© Los autores, 2001; © Edicions UPC, 2001.
n(M
* $t Bt s e$tR $t
{Bt Ns 3ZtIs{$? Bt >qY 3BZtIs $Bt d xdH WB R? BjB j RZ K tB I Zt $8} $B sj? s{ ${B R I RT I$AZ`s Ns } B}$s -}jB s{$? Bt R}s{$sj s? Zt }s s R$R 8sR }jst s $BR { {stBR }s { % s R s js {BtI${$? Bt YZ8sts NBR j? 8$ R R ${ $%BR $8}Z R BR }B js js $%$IsI Yst $8}ZjRsIB s js sj ? s I R{ $ B R I {$ t{$s h{{$? Bt s {Bt{ A$ 8? BIBR sj ts $%BR }s s sP Bt s js $t{Bt8 tRZ sAj $t8 tR$IsI I j R}s{$B q? {t${sR }s s } BjBt s js jBt %$IsI YZ8sts {B8B js st$8s{$? Bt RZR} tI$Is B { $B t$s }s { t YsA R$IB j sIsR s js 8 s {s B ? s I R} {Zjs{$? Bt =ts sj ts $%s $t Rst RZ $Is }B j }$Bt B I js sR Bt? sZ ${s BtR st $t e qR$Bj,B%R,k t d 1M R js I tB8$tsIs ts% t s{$Btsj =t %$s` I 1(( sK tBR I IZ s{$? Bt s Zt I 8$tsIB I R $tB R{s}s I jsR }BR$A$j$IsI R I RZ} %$% t{$s I Zt R YZ8stB _sRsIB R $ 8}B R ? st s{sRB RZR A$9t$ BR JZ$ t R RZ K t t {Bt R I RsP? B Vj s8}s B I jsR } R} { $%sR {tBj? B ${sR s{ Zsj R jsR RZ{ R$%sR t s{$Bt R I YZ8stBR JZ YsA$ s st Zts ts% R}s{$sj tI ? st Zts B}B Zt$IsI }s s % t{ js $8}BR$A$j$IsI I {BjBt$9s{$? Bt I Zt 8ZtIB I$R st t Zts R{sjs I $ 8}B YZ8sts Ns } $8 s ts% t s{$Btsj JZ Ys RZ {sIB j {B8}j `B Zt$% RB I js {$ t{$s h{{$? Bt PZ {Bt{ A$Is }B *Bt G$j{B- t RZ tB% js qY zBks Ys NsR I E(( O s R >d ;(H et jjs sR$R $8BR s jsR $8}B st R sj s{$Bt R RB{$sj R $t BIZ{$IsR }B jBR RZ{ R$%BR I R{ tI$ t R JZ }Z Ajst js ts% I js 8stB I j {s}$ ? st I js 8$R8s JZ I R}$ s I j js B RZ K tB I js Y$A ts{$? Bt {sIs d(( sK tBR FZt B s R st? sj$R$R R} {Zjs $%B I sRPBtIB RB{$Bj? B ${B BA sR {B8B =t$% RB >=t$% R d ;dH I iBA V < $tj $t B Ns ts% R js >WBt 7 B} d xMH I $st G VjI$RR Yst RZ $IB JZ Zt %$s` I sj R {s s{ ? R ${sR {Zj8$ts ? s t Zt sAstIBtB B sj I j BA` $%B I js -} I${$? Bt }B }s I jsR RZAR$ Z$ t R t s{$Bt R VR? t js 8s $R sj tB% js I VjI$RR R sAB Is sj R $jB I j 8$ B }js ? Bt${B I jsR {s% tsR js t$ 8? s ${s -$R t{$s I Zts RB{$ IsI I R{ tI$ t I Zts } $8 s t s{$? Bt I YB8A R k 8Z` R JZ sAstIBts Bt js q$ s t Zts ts% t s{$Btsj {Zks {Bt{ }{$? Bt I j Zt$% RB R R $t s jBR 8BI R BR j? 8$ R I RZ } B}$s ts% WB -$R tsIs 8? sR sjj? s ]ZstIB Zt -$ ZB Z}B I YZ8stBR I R{ZA s{{$I t sj8 t js $t8 tR$IsI I j R}s{$B ABRst I Z $jst R R jjsR RZR 8? sR } BPZtIsR {Bt%${{$Bt R }s { t sR $jjs R }B {B8}j B ! BR sZ B R Yst } P $IB js $8s $ts $%s A? ZRJZ Is I s s`BR s s%? R I js R Z{ Z s I j R}s{$BT $ 8}B }s s RB s jBR $t{Bt% t$ t R I Zt } BjBt sIB %$s` R}s{$sj ej Y$} RT }s{$B ? 8$tB s{ZK tsIB }B FBYt G ]s8}A jj t qY $ Y $ R s{Y$t >d n;H {BtR $ Zk ZtB I jBR I$R}BR$ $%BR $t BIZ{$IBR }s s s{B s j sk { B k }B {BtR$ Z$ t js IZ s{$? Bt I j %$s` I B B 8BIB $tsAB IsAj IsIs js -$R t{$s I Zt j? 8$ I % jB{$IsI R et R t $IB {j? sR${B j Y$} R}s{$B R Ys {Bt{ A$IB {B8B Zt R}s{$B I 8? sR I$8 tR$Bt R IBtI tZ R B Zt$% RB $I$8 tR$Btsj R Ysjjs t? ${s8 t $t sIB 7Z}Bt s8BR JZ Zt 8$t? ZR{ZjB $tT R { B JZ$R$ s {B R s 8$R8s }? s $ts I s $As s sAs`BU I A ? s Ys{ P t s 1x {8 I %$s` s s%? R I j 8ZtIB }jstB I j }s} j 7$ IBAj? s s8BR B s Z ? s s8BR js }? s $ts wsZtJZ {B8 tIs8BR sj j { B sAR t R I sj 8} RsD s8ABR - 8BR R Z$ ? st R }s sIBR 1x {8 s s%? R I j }s} j } B }BI ? st Ysjjs R s 8Zk }B{s I$R st{$s R$ j $tR { B sAstIBts s j }s} j k Rsj s s I Zt - 8B s B B et R ` 8}jB j Rsj B R sj$9s s s%? R I j s$ et tZ R B Zt$% RB $I$8 tR$Btsj jBR Rsj BR tI ? st jZ s s s%? R I j Y$} R}s{$B eR {Z RB Ys R$IB Z $j$9sIB t Zt $t t B I `ZR $h{s {$ t ? h{s8 t jBR $8} BAsAj R %$s` R s 8B BR $t{Bt R I Zts sjs-$s e` 8}jBR {B8B FBt R j YB8A R js >7 s 8st FBt R d xnH I iBA V
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
n(
< $tj $t B js $jB ? s $t${$sIs {Bt Ns Z s I jsR sjs-$sR >7 s Gs R d H I R{ $A t ts% R JZ R I R}js9st s % jB{$IsI R RZ} jZ8? t${sR } 8$ $ tIB j $t {s8A$B {B8 {$sj s s%? R I j Y$} R}s{$B {Bt {ZsjJZ$ }Zt B I RZ j `sts sjs-$s _ R s jjB R Pst ? sR ${B s s`B tB }s { R s - t B I $ R BRU t qY s}8s, R >d xxH I 3 I $, _BYj jBR %$s` R s s%? R I j R$tZBRB Y$} R}s{$B RBt {sj{ZjsIBR 8 I$st Zt 8s}s Y$} R}s{$sj JZ } 8$ j s{{ RB js ZA${s{$? Bt k js Rsj$Is I j 8$R8B sj Zt$% RB sj =ts $t{B {{$? Bt I }B{BR { t ? 8 BR t j 8s}s }Z I sIZ{$ R t Zts tB 8 I$R st{$s t j Zt$% RB sj NBR P { BR k } BAj 8sR I j Rsj B sj Y$} R}s{$B RBt YsA$ Zsj8 t $ tB sIBR }B jBR R{ $ B R I {$ t{$s h{{$? Bt IsIs js sZR t{$s I AsR {$ t ? h{s t j {Bt{ } B ]Bt BIB sj ZtBR sZ B R {B8B yRss{ VR$8B% Yst s% t Z sIB {Z? sj R }BI ? st R jsR R tRs{$Bt R I j %$s` et RZ tB% js et js s ts R js >qY 7 s R N$, *ZR d xdH R{ $A U "uVj YsAjs j {s}$ ? st eR s8BR } }s sIBR }s s tZ R B } $8 Rsj B VAstIBts 8BR 8}B sj8 t js R Z{ Z s I j R}s{$BT $ 8}B }s s s{{ I sj $tB }B{B {BtB{$IB I j Y$} R}s{$B IBtI j $ 8}B k js I$R st{$s tB $ t t R$ t$h{sIB eR {B8B %$s`s }B Zt $R 8B R {YB I Zt B{? stB s B B t jZ s I {$ {ZtIs Zt {Bt $t t }s s jj s sj 8$R8B }Zt B 7? BjB R t $ ? st Zts } JZ K ts 8Bj R $s _B Ps%B 8st t st js {sj8s 3Z {B8B Zts Rs{ZI$Is JZ tBR jj ? B YsR s jBR YZ RBR et Zts P s{{$? Bt I R ZtIB js %$R$? Bt R js I RI jsR R{B $jjsR YsA? s {s8A$sIB sI${sj8 t ej { t B I js psjs-$s R t{Bt sAs sYB s 8? sR { {s k jsR R jjsR }s {? st Ys{ R 8? sR tZ8 BRsR Ns ts% R YsA? s s} B-$8sIB ZtBR {$ t sK tBR jZ9" ej s8A$? t {s}$ ? st I sR Bts% I js tB% js V%B$Ist{ 7$ Zs $Bt >d MnH I F {]Btt jj -}j${s JZ j %$s` s s%? R I j Y$} R}s{$B R "{B8}j s8 t t B {B8T }j s8 t %s{? B" ej } B}$B G jjR Ys{ ZRB I Zt {Bt{ } B JZ$%sj t sj Y$} R}s{$B t RZ js B Ns Y$R B $s I _js t >qY _js t 7 B k dM H IBtI Zt $t{B8} t } BP RB I JZ? 8${s R j$ sj8 t jst9sIB sj Y$} R}s{$B {B8B RZj sIB I Zt -} $8 t B Psjj$IB eR {Bt{ } B %Z j% s Z $j$9s jB t RZ tB% js ej YB8A $t%$R$Aj @ >qY yt%$R$Aj st dM HU "< t{Bt sIB Zt } $t{$}$B t sj Zts P? B 8Zjs Zts -} R$? Bt B8? ${s JZ $t%BjZ{ s {Zs B I$8 tR$Bt R" ]Bt BIB j Y$} R}s{$B {B8}B s Zt } BAj 8s $tRsj%sAj js %$Bjs{$? Bt I ZtB I jBR RZjT sIBR JZ R I $%s I js B ? s I js js $%$IsIU js $8}BR$A$j$IsI I stR8$ $ $tPB 8s{$? Bt s % jB{$IsI R RZ} jZ8? t${sR ej ZRB I Zt s s`B s s%? R I j t s8sIB R}s{$BT 8}B sj R ? s JZ$%sj t sj t%? B I Zts R K tsj s 8skB % jB{$IsI JZ js jZ9 _ W${YBjjR t j j$A B Ns {$ t{$s t js {$ t{$s h{{$? Bt >qY 7{$ t{ $t 7{$ t{ 3${ $Bt d MnH } R t s I$% RBR 8 {st$R8BR $I sIBR }s s %$ s j js B js}RB I R} s t jsR {B8Zt${s{$Bt R $t R js R =tB I jBR 8? sR $t t$BRBR R AsRs t js Z $j$9s{$? Bt I Zts %s $jjs ? $Is I st jBt $ ZI JZ } 8$ $ s R sAj { {Bt s{ B P? R${B t IBR 8ZtIBR I$R st R VR? Ys{$ tIB s stR8$ $ ZRB I Zts {BI$h{s{$? Bt } %$s8 t R sAj {$Is wA$ts $s }B ` 8}jBD R }BI ? $tPB 8s{$? Bt I Zt 8ZtIB s B B R$t 8? sR {tBjB ? s JZ j R$8}j 8B%$8$ t B I js As s _ R =t $t Rst st? sj$R$R I js js{$? Bt t $t%$R$A$j$IsI k %$s` t j $ 8}B I A$IB s _ ]Bs R wd M D RBR $ t JZ " j t{B $8$ t B I js 8s $s s stI R % jB{$IsI R %Z j% sj %$s` B I j $ 8}B $t%$R$Aj $t%Zjt sAj VR? j %$s` B I j $ 8}B I G jjR k RZ <B8A yt%$R$Aj RBt } RBts` R js{$BtsIBR" ! B ` 8}jB jB t{Bt s8BR t j hj8 ej -} $8 t B 3$jsI jhs >d M;H IBtI Zt I R Z{ B I js s 8sIs I jBR eR sIBR =t$IBR R sRjsIsIB I d ;n s jBR sK tBR M( IZ st Zt 8$R $BRB -} $8 t B {Bt {s8}BR 8s t? ${BR $t tRBR @
© Los autores, 2001; © Edicions UPC, 2001.
nd(
* $t Bt s e$tR $t
3$ E d( 5=ts PB 8s R$8}j I {B8Zt${s{$? Bt {Bt $t j$ t{$sR - s R R2 sj $t t$B Z $j$9sIB Zt I$R}BR$ $%B {B8B ? R tB R ? s B} s $%B 8? sR sjj? s I j Zt$% RB I js {$ t{$s h{{$? BtU t } $8 jZ s tB R }Z I 8st t js $ $I 9 I Zts R Z{ Z s I sj R I$8 tR$Bt R _B B B jsIB t jBR $t t BR }B I R}js9s Zt {Z }B } ? s{ ${s8 t $ts8B%$Aj IsIs RZ st 8sRs t s ? s8BR s jB RZ8B BtIsR I } R$? Bt JZ R } B}s s ? st }B js As s s % jB{$IsI R 8Zk $tP $B R s js I js jZ9 ej stR$Aj {B8Zt${sIB $tR st ? st B $t BIZ{$IB }B = RZjs N pZ$t t NBR I R}BR ? IBR >qY *$R}BRR R I d ;H k Z $j$9sIB }B B BR sZ B R t tB% jsR {B8B ej `Z B I etI I ! RBt 7{B ]s I {BtR $ Zk Zt ` 8}jB I I$R}BR$ $%B 8? sR RBhR ${sIB et NBR I R}BR ? IBR R } R t s j stR$Aj {B8B P Z B I Zts {tBjB ? s AsRsIs t Zts tZ %s s8s I js P? R${s JZ %$ t s {B8}j s sj ZtBR sR} { BR I js B ? s I js js $%$IsI t jBA? stIBjs {B8B {sRB }s ${Zjs ? sR Pst ? sR ${B JZ$9? sR RZj s j {B8Zt${sIB *$ s{ s}s {$IB t j js B } >d x;H I Fs8 R j$RY s8}j$sIB {Bt }BR $B $IsI s js tB% js qY +Z$t{Zt- BP q$8 >d nH *${YB I$R}BR$ $%B } 8$ j t%? B I 8 tRs` R $tR st ? st BR s {ZsjJZ$ B B {B8Zt${sIB *$ s{ gI j } R t }sRsIB B PZ Z B ]sIs 8 tRs` %$ t } { I$IB I Zt }$ $IB wA }D {Bt Zt R} { B {Bt $tZB JZ R - $ tI I RI jBR n( s jBR dM!((( <9 k JZ 8$ts }B {BtR $ Z$ js B sj$IsI I 8 tRs` R *$ s{ JZ Yst R$IB B R ? st t%$sIBR 5+Z? I$R}BR$ $%B R ? s {s}s9 I R }s s Zt 8 tRs` {Bt{ B I st {B8}j `s RZ} }BR${$? Bt I R K tsj R2 ej PZt{$Bts8$ t B I j {B8Zt${sIB *$ s{ }BI ? s AsRs R t Zts {Bt B% $Is B ? s } B}Z R s }B jBR P? R${BR FBYt V GY j k i${Ys I _ 3 kt8st t d ;d _s s s8ABR Zts {s s j? { ${s s{ j sIs tB sI$s ? s -{ } B R$ tB YZA$ s sARB {$? Bt t Zt {$ B }Zt B I j R}s{$B k t Zt {$ B $tR st PZ Z B * sj sh 8s{$? Bt R P? s{$j I IZ{$ JZ j PZ Z B I 8$ts j }sRsIB *${Ys $I s }s { Y IsIs I Zt }jst s8$ t B R$8$js }ZAj${sIB }B j P? R${B <Z B q BI t d 11U j 7Bj tB sI$s ? s R$ tB
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
ndd
YZA$ s tsI$ }s s sARB A Rs sI$s{$? Bt qs8A$? t j JZ? 8${B p N b$R sh 8? B t d 1E JZ Zt s ? B8B tB 8$ $ ? s jZ9 R$t B B s ? B8B JZ js sARB A$ s ]Z $BRs %$R$? Bt I j 8ZtIB P? R${B R 8 `st s sh 8s JZ R$ YZRs8BR 8$ s Zts I 8$tsIs R jjs I j h 8s8 t B R s tB{Y R s 8BR sj stIB js jZ9 8$ $Is }B js } B}$s R jjs Ys{ 8$j R I sK tBR _B B B jsIB js 8 s -$R t{$s I j {B8Zt${sIB *$ s{ }jst s js Y$}? B R$R I Zt Zt$% RB I 8$t$R s IBtI j PZ Z B tB }BI ? s % R sj sIB }B 8BI$h{s{$Bt R $t BIZ{$IsR t $ 8}BR } ? $ BR s`B j } $R8s I j I 8$t$R8B j {B8Zt${sIB *$ s{ tB %$Bjs ? s js j k I {sZRsj$IsIU jBR 8 tRs` R *$ s{ } B% t$ t R I j PZ Z B R s ? st ks } %$R BR _ R s jjB }s { $8}BR$Aj {B8}s $ts R s %$R$? Bt {Bt js 8 {? st${s {Z? st ${s JZ s}B s tZ %BR j 8 t BR I $t{ $IZ8A t js I R{ $}{$? Bt I jsR 8s t$ ZI R P? R${sR _B JZ 5}Z I {Bt{ A$ R Zt PZ Z B I${ sIB }B 8 sR {BtI${$Bt R $t${$sj R {ZstIB tB -$R { 9s sj Zts t js I 8$ts{$? Bt -s{ s I js }BR${$? Bt I Zts RBjs }s ? {Zjs j 8 t sj2 =t ` 8}jB I$R}s s sIB I {B8Zt${s{$? Bt $tR st ? st s t IBR }Zt BR 8Zk sj `sIBR - t B I BIs AsR {$ t ? h{s }Z I t{Bt s R t j hj8 > k 7 }8B Y $R st Vj$ t d MMH IBtI R tRsks Zt -} $8 t B }s s t%$s Zts R K tsj j { B8s t? ${s s Zt }Zt B I j R}s{$B R$ ZsIB s 1 sK tBR jZ9 I js q$ s ej R}BtRsAj I j } Bk { B s%sjs js $8}BR$A$j$IsI I R s t s $%s s Z8 t stIB JZ }s s t%$s Zts R K tsj s B s sjs-$s R t { R$ s ? s } B}ZjRs js R K tsj s Zts % jB{$IsI RZ} $B s js I js jZ9 ]B8B RZj s BA%$B RB R {B8}j s8 t PsjRB Ns I$h{Zj sI ? {t${s sI${s t js }B t{$s I js R K tsj IsIs RZ } B R$%s s tZs{$? Bt }B } B{ RBR I sARB {$? Bt sj s s% Rs }B ` 8}jB tZA R I }Bj%B $t R js ]Bt BIB js R{sjs I $ 8}B t { Rs $s }s s sj{st9s RZ I R $tB {Bt $t? Zs j$8$ sIs }B js B ? s I js js $%$IsI ]B8B {Bt{jZR$? Bt tB R }Z I t%$s $tR st ? st s8 t Zts R K tsj s 1 sK tBR jZ9 I js q$ s sj k {B8B RZ{ I t j hj8 O 8 tBR s? Zt {$A$ js %$R$ s I Zts ts% } B{ I t I I${YB jZ s sj I? s R$ Z$ t _ R s RZ 8s {sIB tPBJZ YZ8B ? R ${B R s } j? {Zjs {BtR $ Zk Zt {js B ` 8}jB I ZRB k sAZRB I ? 8$tBR k {st $IsI R {$ t ? h{sRU "e-$R t 1(( 8$jjBt R I R jjsR t tZ R s psjs-$s" ]Bt sj sh 8s{$? Bt tB RZj s RB } tI t JZ j * 7 % $jjR 8$t }B R -}ZjRsIB I j } Bk { B ej t? Z8 B I R jjsR I js z? s N? s{ s R R $8s tBR jZ9 t %Bj% s {sRs" ej sK tB jZ9 R Zts t ZtBR 1((!((( 8$jjBt R "qs Is 8BR 1 sK Zt$IsI I jBt $ ZI tB I $ 8}B "z t$8BR I Zt }jst s s 1 sK tBR jZ9 I sJZ? `ZR B s 1 R$R 8sR RBjs R I I$R st{$s" Ns I$R st{$s ? }${s t R$R 8sR RBjs R R I ZtBR }B{BR sK tBR jZ9 et {Bt{ B js I$R st{$s s js R jjs VjPs ] t sZ $ R I R? BjB ;, ; sK tBR jZ9 _ R s JZ tB -$R t Is BR BAR %s{$Btsj R I ht$ $%BR R j? B ${B } tRs JZ j t? Z8 B I R$R 8sR }jst s $BR s 1 sK tBR jZ9 I I$R st{$s R s AsR st 8skB JZ 1 wYsR s js P {Ys R Ys I R{ZA$ B Zts IB{ ts I }jst sR - sRBjs R s I$R st{$sR $tP $B R s 1 sK tBR jZ9D ! A$ t jBR $tR$ t R - s R R JZ tBR %$R$ st t js } j? {Zjs stIst Zt }B{B } I$IBR }B js psjs-$s B $t t st I j$A sIs8 t B{Zj s RZ jZ s I } B{ I t{$s
$ tB%$s R Zts - s R
=tB I jBR I$R}BR$ $%BR 8? sR {? j A R I j Zt$% RB I js {$ t{$s h{{$? Bt R j B yt BIZ{$IB }B % 9 } $8 s t >qY *$R$t s $Bt s{Y$t d 1 H I V YZ ]Btst *Bkj Ys {BtR $ Z$IB Zt j 8 t B } $8B I$sj t 8Z{YsR
j }B sIB
Ns 8? sJZ$ts I R$t sIB s
j stR}B
eR 8Zk } BAsAj JZ I${YB B R I As s Zts I P { ZBRs sIZ{{$? Bt I j B $ $tsj et eR sIBR =t$IBR R I R$ ts {B8B A$jj? Bt s 8$j 8$jjBt R VR? 1((!((( 8$jjBt R I R jjsR {B R}BtI ? st s 1(( A$jjBt R
© Los autores, 2001; © Edicions UPC, 2001.
nd1
* $t Bt s e$tR $t
tB% jsR k } j? {ZjsR I j ? t B {B8B eR s{$? Bt I ? stR$ B >Gsk 7 s $Bt d EnH I ]j$&B I * 7$8s, ZtIB st$jjB >i$t bB jI d (H I Ns k W$% t j hj8 qY q$8 q s% j R B YsR s js Rs{$ IsI t js 8skB ? s I j hj8 R k } j? {ZjsR I j Zt$% RB q , ! B ` 8}jB I R s{sIB jB {BtR $ Zk j js B Ns 8BR{s >qY 3jk d x H I p B Nst jsst k RZ sIs} s{$? Bt {$t T 8s B ? sh{s YB8? Bt$8s >qY 3jk d xMH hj8 I {$ t 8s, >qY 3jk d MEH k I$% RsR R {Z jsR w>i Z t BP Y 3jk d x H >qY ]Z R BP Y 3jk d ExH k Ns 8BR{s yy >qY 3jk yy d MMHD ej stR8$RB I 8s $s I j * VtI ? * js8A j {$ t ? h{B I Ns 8BR{s R AsRs t Zt } B{ RB I I R$t s{$? BtT $t s{$? Bt JZ } 8$ sRjsIs {Z }BR 8s $sj R Ns } BAsT A$j$IsI I JZ BIsR jsR }s ? {ZjsR j 8 t sj R JZ {BtR $ Zk t Zt B st$R8B R s Z} t }B s9s k {BtR Zkst js {Bth Z s{$? Bt $t${$sj R } ? s{ ${s8 t tZjs 7 JZ$ Zt I$R}BR$ $%B R}BtRsAj I } B{ Rs BIs js $tPB 8s{$? Bt sj8s{ ts jsR }BR${$Bt R k B sR %s $sAj R P? R${sR I {sIs }s ? {Zjs k {Bt Bjs j } B{ RB I $t s{$? Bt WB R I$R}Bt s{ Zsj8 t I js {tBjB ? s t { Rs $s }s s sP Bt s j st %BjZ8 t I Is BR $t%BjZ{ sIB t R } B{ RBU Ysk s B8BR t j {Z }B YZ8stB _s s {sIs ZtB I jjBR JZ $8BR n {BB I tsIsR ZtBR d( M ? R}s{$sj R }s s h`s RZ }BR${$? Bt 8? sR Zts js s j$R s I $tPB 8s{$? Bt RZ}j 8 t s $s js $%s s % jB{$IsI R R}$t R sIBR I %$A s{$? Bt { _Z I R $8s R t d ,$jBAk js $tPB 8s{$? Bt t { Rs $s }s s $I t $h{s {Bt } {$R$? Bt j R sIB I {sIs s ? B8B I j {Z }B YZ8stB eR B R Bt _s s Ys{ tBR Zts $I s I I A 8BR Ys{ P t sj t%? B I ZtBR d(1M ,$jBAk R I $tPB 8s{$? R t? Z8 B js $tPB 8s{$? Bt {Bt t$Is t BIBR jBR j$A BR R{ $ BR }B js YZ8st$IsI sj I IB I I$ 9 8$jjBt R I %Bj? Z8 t R sR{$ tI Z ?t${s8 t s d(d( T d(dd ,$jBAk R W { R$ s ? s8BR 1d Bt ]Bt Zt BRB ZtBR d( I$R{BR IZ BR I d( $ sAk R }s s sj8s{ ts BIs js $tPB 8s{$? I j B I t I d {8 }B I$R{B js $tPB 8s{$? Bt js $%s s Zt Z ?t${B {Z }B YZ8stB B{Z}s ? s {Bt tZ R s {tBjB ? s s{ Zsj 8? sR s%st9sIs ZtBR d ((( sK tBR jZ9 s} B-$8sIs8 t ZtsR 1(( % { R js I$R st{$s JZ tBR R }s s I VjPs ] t sZ $ js R jjs 8? sR } ? B-$8s 7$ }ZI$? s8BR } R{$tI$ uJZ tB }BI 8BRu I BIBR jBR } BAj 8sR ? {t${BR I $%sIBR I j sjT 8s{ tsIB I js $tPB 8s{$? Bt }BI ? s8BR { t s tBR t jBR sR} { BR js $%BR sj $ 8}B t { Rs $B }s s stR8$ $ sj $t t %BjZ8 t I Is BR NBR I$R}BR$ $%BR {B8 {$sj R I stRP t{$s s8BR I $tPB 8s{$? Bt 8? sR ? s}$IBR I js s{ Zsj$IsI B} st s d pAk \R V R $ 8B t { R$ s ? Bt {Bt t$Is t Zt R YZ8stB s} B-$8sIs8 t n d(d; ZtBR d(11 R }s s } B{ Rs js $tPB 8s{$? sK tBR R I {$ ZtsR 1( ((( % { R js } B}$s IsI I j Zt$% RB O RB Z ?t${s8 t }s s j t%? B I js $tPB 8s{$? Bt 7Z BA t{$? Bt $ 8}B I sj8s{ ts8$ t B t RB}B sR? {B8B RZ { }{$? Bt k js }BR $B $t s{$? Bt I j {Z }B B $ $tsj sZ8 t s ? st RZR st{$sj8 t Rs {st $IsI WB I A 8BR Bj%$Is 8} B JZ jBR {Bt 8}B ? st BR I N Bts IB Is z$t{$ YZA$ st t { R$ sIB I? {sIsR }s s stRP $ js $tPB 8s{$? Bt JZ$%sj t s d $ sAk {Bt RZR R$R 8sR 8 {? st${BR } B{ RB JZ YBk t I? s }Z I sj$9s R t d R ZtIB ej P? R${B Nsb t{ sZRR R $8s JZ js 8 `B s t j sj8s{ ts8$ t B k t js % jB{$IsI I stRP t{$s sZ8 t s t Zt Ps{ B d(( }B I? {sIs V R $ 8B R ? s8BR {s}s{ R I sj{st9s jBR JZ $8$ t BR ? {t${BR I j j T stR}B t }B{B 8? sR I d(( sK tBR Vj 8s t I jBR } BAj 8sR ? {t${BR I {BI$h{s{$? Bt k stRP t{$s I $tPB 8s{$? Bt } R$R t } BPZtIBR $t B st R I B s ? tIBj U Zts R Z{ Z s %$%s }s { R sj B 8? sR JZ Zt 8 B {Bt`Zt B I s ? B8BR s Z}sIBRU 5PZt{$Bts ? s js ? }j${s t jsR 8$R8sR {BtI${$Bt R JZ j B $ $tsj2 et j {sRB I Zt R YZ8stB 5{BtR %s ? s RZ { A B BIBR jBR {Z IBR st $B R2 5RZR R t $8$ t BR2 WB R ? s tsIs {js B _B B B jsIB js } B}$s P? R${s {Z? st ${s }s { {BjB{s sj j stR}B {Bt s jsR {Z IsR et j } B{ RB I 8 I${$? Bt
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
ndn
I jsR } B}$ IsI R I Zt s ? B8B I A t Z $j$9s R PB Bt R I jBt $ ZI I BtIs } JZ K ts k }B {BtR$ Z$ t 8Zk t ? ${BR ej $8}s{ B I Zt PB ? Bt I sj s t ? s {Bt Zt s ? B8B jB } T Z As $ 8$R$Aj 8 t ej } B}$B } $t{$}$B I $t{ $IZ8A I < $R tA I R%st { j RZ K tB I I 8$ts {Bt sARBjZ s } {$R$? Bt jsR {s s{ ? R ${sR I js 8s $s s R{sjsR 8${ BR{? B}${sR _s s RZARsts sj I$h{Zj sI jBR Z$Bt$R sR I 7 s q , Z $j$9st Zt {Z $BRB s $jZ $B jBR jjsT 8sIBR {B8} tRsIB R < $R tA JZ } 8$ t RBjZ{$? Bt {Z? st ${s =t sR} { B I ht$ $%B I j j stR}B R j JZ$R$ B I ZtsR {s s{ ? R ${sR I BAR %s{$? Bt $8} R$Btst R }s s jB s RBjZ{$? Bt {Z? st ${s I RI Zt sj{st{ 8? s-$8B I ;(!((( ,8 7 ? Zt sZRR js j t I j j T R{B}$B I j et } $R }s s RBj% Zt BA` B s R{sjs s ? B8${s I RI ;(!((( ,8 -{ I ? s jBR x(!((( ,8 I I$? s8 B * Y {YB j } B}$B ZRB I R 8 `st R jBt $ ZI R I BtIs wIB8$t$B B s88sD }s s RBj% jBR s ? B8BR I j {Z }B JZ R I R s stR}B s RZj s ? s RZ8s8 t } `ZI${$sj }s s js RsjZI eR %$I t JZ } R sj s%st{ t 8s $s I j {B8Zt${s{$Bt R tBR R }s s Zt sA$R8B I jBR JZ$R$ BR t { Rs $BR }s s JZ j j stR}B R s B} s $%B sj ? Zt I? s ! BR sZ B R Yst s}Zt sIB ZRBR sj ts $%BR I j j stR}B U R$ }ZI$ s IZ}j${s R } P {T s8 t Zt B $ $tsj }BI ? st t s R {B}$sR I Zt B st$R8B %$%B sj B BIs%? s 8? sR %BjZT {$Bts $B JZ js } B}$s {jBts{$? Bt et {sRB I s{{$I t }BI ? s 8}j s R Zts {B}$s I R Z $IsI }s s 8}js9s sj Psjj {$IB VR? t "7Bj IsI t {B8}sK t? s" >NBt jk V8Bt =R d M H }$RBI$B I 7 s q ,U js tZ %s t s{$? Bt j } B}$B {s}$ ? st F stTNZ{ _${s I R R sZ sIB sR R stRP $IB I PB 8s I P { ZBRs Ys{$ tIB ZRB I js $tPB 8s{$? Bt {BI$h{sIs I RZ B st$R8B {Bt t$Is t j B I tsIB I js ts% _ B 5 tI ? s js {B}$s {BtR{$ t{$s } B}$s2 5_BI ? st t s R ? }j${sR JZ }s ${$}s st I Zts {B8Zt$? Bt I {Z IBR k -} $ t{$sR I j }sRsIB2 et 7 s q , }s { JZ R? 7$t IZIs jsR }BR$A$j$IsI R sA$ sR }B R s $I s RZj st $tJZ$ T st R ! sR $8}j${s{$Bt R I j j stR}B YsA? st R$IB s}Zt sIsR ks t js R $ {j? sR${s >7 s q , d EETE HU 5JZ? t%? s -s{ s8 t j j stR}B sIB 2 5Ys{ R I 8s $s B $tPB 8s{$? Bt2 e}$RBI$BR {B8B "qY et 8k G$ Y$t" >d EEH IBtI j {s}$ ? st Fs8 R q $ , R I RIBAjs t 1 {B}$sR I R? 8$R8B JZ 8ZjstIB sj * F ,kjj k <kI tP t st j A$ t k j 8sj RZ $ t j t%? B I $tPB 8s{$? Bt Ns R$8}j {BtR %s{$? Bt I 8s $sT t ? s $8} I$ ? s IZ}j${s j t? Z8 B I {B}$sR n <s{$s j 8$R8B R t $IB }s { s}Zt s j IZ}j${sIB I sj$8 t BR I$RT }BR$ $%B JZ } 8$ R$t $9s Zt I 8$tsIB } BIZ{ B Z $j$9stIB Zts PZ t I t ? s JZ } B}B {$Bt 8s $s 8BI jsIs 8 I$st js $tPB 8s{$? Bt {BI$h{sIs t Zt B I tsIB s }s $ I Zt }s ? Bt B $ $tsj ]Bt R } B{ I$8$ t B js ts% et } $R }Z I sP Bt s 8$R$Bt R I js s IZ s{$? Bt jZI$ tIB j {B8}j `B } BAj 8s I j s} B%$R$Bts8$ t B ej j stR}B {B8}B s js -$R t{$s I Zt 8$RB R}BtRsAj I jBR } B{ RBR I I R$t T s{$? Bt {BI$h{s{$? Bt k stR8$R$? Bt I js R K tsj k I Zt { } B }s s jsR PZt{$Bt R I { }{$? Bt k $t s{$? Bt I js $tPB 8s{$? Bt VR? 8$ t sR j j stR}B t ts% R I js 3 I s{$? Bt JZ$}sIsR {Bt R s {tBjB ? s }s { %$sAj I t B I jBR 8? s t R {$ sIBR tB R -}j${s {? B8B Zts ts% }Z I Z $j$9s R {Z RB }s s t%$s Zt JZ$}B I -}jB sIB R s Zt }jst s JZ tB
ej I$R}BR$ $%B I R$t sIB T $t sIB I Ns 8BR{s {B8}B s Zts {js s %$Bjs{$? Bt I js {BtR %s{$? Bt I js 8sRs Ns R {Z t{$s t js JZ VtI ? * js8A sIJZ$ js {sA 9s I js 8BR{s sR? {B8B Zts I RZR }s sR $t{Z t Zt B I I$8 tR$Bt RU js {sA 9s I js 8BR{s ZA${sIs t j {Z }B I j {$ t ? h{B R stB 8sj8 t stI R$t t$t Zts -}j${s{$? Bt {BY t }s s j -{ RB I 8s $s $t%BjZ{ sIB 1n
© Los autores, 2001; © Edicions UPC, 2001.
nd;
* $t Bt s e$tR $t
Ys R$IB } %$s8 t %$R$ sIB k JZ {BtR {Z t 8 t tB }BR t$t ? Zt { } B =t ` 8}jB jB t{Bt s8BR t 7 s q , yyyU t AZR{s I 7}B{, >7 s q , yyyU Y 7 s {Y PB 7}B{, d M;H +Z? R t $IB tI ? s I B s PB 8s js j $? Bt I YZ8stBR I js tB% js z$s` $t 8$tsAj >etIT j RR zBks d xH I s $Bt $8 sIj k JZ I I${st js 8skB }s I RZ %$Is s %$s`s }B $tY? BR}$ sR $Bt R I j Zt$% RB {Bt j Z ?t${B BA` $%B I ZA${s { } B R }s s js {BjBt$9s{$? Bt Bt${sR R s sR D I B BR 8ZtIBR w{B8B R$ I {sA$tsR j P?
E E ? sR P? R${s I jBR %$s` R t j $ 8}BU s Z` BR I ZRstB k B BR j sIBR I js js $%$IsI t sj =ts $ s t js B8 ? s I j R}s{$BT $ 8}B Ns 8? sJZ$ts {Bt RZ -$ Zs $}Zjs{$? Bt YZ8sts } t sAs }B Zt js B ? Zt j BR{Z B Zt sA$R8B $tRBtIsAj I - Z s $ Zjs eR sAst {sk tIB k js R tRs{$? Bt I %? $ B }s {? s Zt$ R s js st ZR $s }B R{js { js ts Z sj 9s I j ? Zt jU "eR Zt s Z` B t B u} tR? B ej stB V Bbsku R Bk I R} K tstIB }B Zt s Z` B t B sZtJZ s jB 8 `B thjB I$ { B Ys{$s Zts R$t Zjs $IsI I RtZIs {B8B js jjs8st jBR P? R${BR et jsR } B-$8$IsI R I Zts R$t Zjs $IsI R %$Bjst jsR j k R I js {sZRsj$IsI jBR P { BR }Z I t } { I s jsR {sZRsR j $ 8}B R B s 8Zk I$P? {$j8 t ZtB }Z I RBA %$%$ k 8Z{YB 8 tBR {B Is js -} $ t{$s NBR s Z` BR t BR RBt BA` BR R$t$ R BR 7$ tBR I R{Z$Is8BR k {s 8BR t jjBR jsR }BI BRsR PZ 9sR s%$ s{$Btsj R tBR R $ s ? st YsR s {Bt% $ tBR t Zt Y$jB js B k I j sIB O s8A$? t tBR s}jsR s ? st t R t $IB js sj" et js s js 8 s $s BI$R s I I? {sIs I jBR M( j {BtB{$IB sR ? BtB8B ]s j 7s st wd n;Td ED I R{ $A? {$t{B R R YZ8stBR t RZ tB% js ]Bt s{ B >]Bt s{ d MxH Zt %$s` sjZ{$tst s s%? R I Zt 8$R $BRB }? B ${B s jsR R jjsR JZ jBR jj %s YsR s js I$R st R jjs z s t js {BtR js{$? Bt I js N$ s s`B js Z js I j } R $ $BRB P? R${B ? B ${B $} qYB t 7s st RAB9? B Zt R$R 8s I stR}B JZ } 8$ ? s sP Bt s js js s s% R? s YsR s j { t B sj? s{ ${B t Zts R{sjs I $ 8}B YZ8sts Ns js $%$IsI t sj w]ZsI BR E n k E ;D B s I jsR stI R s}B s{$Bt R I e$tR $t s js P? R${s {Bt 8}B ? st s } 8$ js -$R t{$s I A {YsR k s s`BR t js R Z{ Z s I j R}s{$BT $ 8}B ? Zt j R JZ } 8$ t RB s jsR j$8$ s{$Bt R $8}Z R sR }B js % jB{$IsI I js jZ9 t js IZ s{$? Bt I Zt %$s` $t R js Vj B R$8$js s jB $8s $tsIB }B jBR Z$Bt$R sR I j hj8 7 s s >d EH Os t d ; j {? j A 8s 8? s ${B sZR ? s{B Z p[ BI j wd (ETd MD {BjsAB sIB I e$tR $t t j ytR $ Z B I eR ZI$BR V%st9sIBR I _ $t{ Bt }ZAj${sAs ZtsR RBjZ{$Bt R s jsR {Zs{$Bt R I {s8}B s%$ s B $B I js js $%$IsI t sj JZ $8}j${sAst js }BR$A$j$IsI ? B ${s I j %$s` t j $ 8}B 7 s sAs I Zt 8BI jB R$8}j$h{sIB I Zt$% RB t B s{$? Bt I s8sK tB $tht$ B k {BtR $ Z$IB }B Zt 4Z$IB } P { B _ R s js {Bt B% R$s RZR{$ sIs }B j 8BI jB I p[ BI j j st? sj$R$R k js I IZ{{$? Bt 8s 8? s ${s I js RBjZ{$? Bt RZj sAst $8} {sAj RU tB } R t sAst t$t ? Zt B eR ZI$BR }BR $B R Yst I 8BR sIB JZ j %$s` t j $ 8}B tB {BtR $ Zk Zts 8 s stB8sj? s I j 8BI jB I p[ BI j R$tB JZ R Ysjjs $t8 RB t jsR } B}$sR {Zs{$Bt R I js js $%$IsI t sj Ns 8skB BA` {$? Bt % $Is RBA j 8BI jB I p[ BI j sI${s t RZ Psj s I {Bt{B Ist{$s {Bt j Zt$% RB sj WZ R B Zt$% RB R -}stI } B tB } R t s Zts B s{$? Bt s} {$sAj !AR R$BtsIB }B jsR $8}j${s{$Bt R I j %$s` t j $ 8}B p[ BI j }sR? B jBR Z ?j $8BR sK tBR I RZ %$Is $t% R $ stIB {ZsjJZ$ $tI${$B I B s{$? Bt I j Zt$% RB _ R s JZ j 8BI jB
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
ndx
I p[ BI j {BtR $ Zk Zt }Zt B I $t4 -$? Bt sj sAB Is js %$sA$j$IsI I j %$s` t j $ 8}B RZR $8}j${s{$Bt R tB jj s Bt tZt{s s } t s t jsR BA sR I {$ t{$s h{{$? Bt WB -$R Zts RBjs tB% js I j ? t B AsRsIs t j 8BI jB I p[ BI j WB BAR st j } B}$B Z p[ BI j s}s { {B8B $t R} sIB } B s Bt$R s I js tB% js NsR ts% R I j $ 8}B >qY q$8 7Y$}R d xH I j A $ ? st${B 7 }Y t s- ! BR {stI$Is BR s 8? sJZ$ts I j $ 8}B JZ 8 t I j R$tZBRB hj? Bt I js js $%$IsI t sj RBt jBR s Z` BR t BR IB sIBR I B s{$? Bt B s Z` BR t BR I AsZ $9sIBR t YBtB I j 8s 8? s ${B t B9 jstI? R iBk JZ$ t t d En PZ j } $8 B t RBj% jsR {Zs{$Bt R I js js $%$IsI t sj }s s Zt 8BI jB I s Z` B t B t B s{$? Bt NBR s Z` BR t BR sRB8s Bt t j h 8s8 t B I jsR B ? sR P? R${sR I js 8stB I jBR sAs`BR }$Bt BR I FBYt $ {Y jj wd 1;Td nD $tI } tI$ t 8 t I _$ 7$8Bt 8s JZ? R I Ns}js{ wd ; TdM1 D 7Z B $ t I Rj$ sIB I {ZsjJZ$ BA` B BAR %sIB t j Zt$% RB BA I {? s s Zts - s}Bjs{$? Bt $8s $ts $s RBA jsR } B}$ IsI R JZ tI ? s Zt {Z }B IB sIB I Zts % jB{$IsI I R{s} JZ -{ I$ s js % jB{$IsI I js jZ9 et d dE j sR ? BtB8B sj 8? st s j 7{Ybs 9R{Y$jI wdM nTd dED I IZ`B jsR } B}$ IsI R I Zt s Z` B t B {j? sR${B R ? s ${B k R$t {s s s }s $ I jsR {Zs{$Bt R I js js $%$IsI t sj <Bk t I? s s s? 9 I jBR sAs`B }$Bt BR I jBR P? R${BR iBA F !}} tY $8 k <s jstI 7tkI t d n jBR s Z` BR t BR R sRB{$st PZtIs8 t sj8 t {Bt jBR Z ?j $8BR R sI$BR I js %BjZ{$? Bt I R jjsR 8sR$%sR =t s Z` B t B }BR Zts s% IsI st - 8s JZ js } R$? Bt ` {$Is }B js 8s $s tB {BtR$ Z R sA$j$9s js R jjsU j 8s $sj R I Z8As t Zt {Bjs}RB R$t ht JZ { s Zts R$t Zjs $IsI t js R Z{ Z s I j R}s{$BT $ 8}B qBIB s Z` B t B I A }BR Zts R$t Zjs $IsI { t sj et I${YB }Zt B jsR j k R I js P? R${s I `st I t %sj$I 9 Ns {Z %s Z s t jsR $Bt R } ? B-$8sR s js R$t Zjs $IsI R st - 8s JZ jBR P { BR I js s% IsI R ? st BA tsIBR }B js 8 {? st${s {Z? st ${s _s s sj ZtBR P? R${BR {B8B FBYt V GY j js $t{jZR$? Bt I jBR P { BR {Z? st ${BR }BI ? s sj s RZR st{$sj8 t j {BtB{$8$ t B RBA jB JZ RZ{ I t RZ $t $B JZ R t{Z t s 8? sR sjj? s I BIs s{{ R$A$j$IsI } B $IB }B j YB $9Bt I RZ{ RBR P Bt s 8s 8? s ${s JZ I ht j jZ s B8? ${B sj I IB I Zt s Z` B t B }s s j JZ js % jB{$IsI I R{s} $ Zsjs s js I js jZ9 ej YB $9Bt I RZ{ RBR B{Zj s Zt RB } tI t I } IsIB {? BR8${B JZ } s{ ${s j $ Zsj I j {st$Asj$R8B {Bt R jjsR % {$tsR k JZ R sj$8 t s I $tPB ZtsIBR sR BtsZ sR JZ BRst s{ T {s R I 8sR$sIB s RZ RZ} h{$ =t $Aj I R $tB s Zs Is s sJZ jjBR JZ I {$Ist { Z9s 8 s $s8 t j YB $9Bt I RZ{ RBRU tB -$R B tB IsIB JZ }s s 8 I j YB $9Bt R JZ $ ? st % jB{$IsI R RZ} jZ8? t${sR Z{YB st R j $t{sZ B sR BtsZ s YsA ? s -} $T 8 t sIB $ ? st${sR PZ 9sR I 8s s JZ jB YsA ? st IZ{$IB s Zts h Z s hj$PB 8 _B R$ RB PZ s }B{B RZR R BR 8$ts ? st {$A$ tIB Zts IZ{Ys j sj I sI$s{$? Bt sj } t s t j $t $B ]Z $BRs8 t t "_Ys " >d xH Zt }$RBI$B Y$R ? B ${B I js {$ t R $ 7 s q ,U zBks t? R$8s { s{$? Bt I j Zt$% RB q , j {s ? s{ }Z s8 t 8s 8? s ${B I j YB $9Bt I RZ{ RBR tB RZ}Bt t$t ? Zt BAR ? s{ZjB }s s jsR {Z $BRsR PB 8sR I %$Is JZ YsA$ st j $t $B I Zt s Z` B t BU s} B% {YstIB Zts $ s } R t t j YB $9Bt {BtR$ Z t jB $8}BR$Aj U g R{s}s I j s Z` B t B =t {Z $BRB 8 {st$R8B R$t IZIs JZ$%sj t s I R}js9s R }B js RZ} h{$ I js q$ s }stIB }B }s sj jBR k 8 $I$stBR
© Los autores, 2001; © Edicions UPC, 2001.
ndE
* $t Bt s e$tR $t
]ZsI B E n Ns js $%$IsI t sj k RZR B ? t R =tB I jBR 8skB R jB BR I js P? R${s {j? sR${s PZ js I R{ $}{$? Bt I j 8B%$8$ t B }jst T s $B {ZksR BAR %s{$Bt R R s`ZR sAst I PB 8s 8Zk } {$Rs s jsR } I${{$Bt R % $IsR }B js 8 {? st${s t b Bt$sts ej 8B%$8$ t B I {Z $B {BtR $ Z? s Zts tB sAj -T { }{$? Bt 7Z B ? A$ s sj I IB I j 7Bj tB s9sAs Zts j$}R } P { s R$tB JZ ? R s }s {? s $ s{B8}sK tsIs I Zts j % B s{$? Bt P { B {BtB{$IB {B8B } { R$? Bt I j } $Y j$B ytT {jZRB R jj ? B s R} {Zjs {Bt js }BR$Aj -$R t{$s I Zt } JZ K tB }jst s AsZ $9sIB {B8B zZj{stB ZA${sIB t {Z $B k j 7Bj JZ ` { ? s } Z As{$Bt R s%$ s B $sR t Bt 7 s q , {Bt% $ ? s sj }jst s zZj{stB t js B ? A$ s I j } $8 B wjs R $ I j %$R$? }B}Zjs sj {BtR $ Z$ js {Zts $8s $ts $s I j $tR$ t 7}B{,D VJZ? PZ IBtI e$tR $t 8ZjstIB s jBR $}Zjst R I j et } $R jj ? B IBtI tsI$ YsA? s jj sIB st R -T }j${stIB j B $ t I j P t? B8 tB k {Bt t$stIB RZ $tRs $RPs{{$? Bt R ? ${s s{ {s I js I$P t{$s t s{ j s{$? Bt k s% IsI et RZ {? j A } $t{$}$B I JZ$%sj t{$s }$ I s st Zjs I RZ tZ %s B ? s I js s% IsI js js $%$IsI t sj e$tR $t R sAj {$? B js JZ$%sj t{$s t s{ j s{$? Bt k s% IsI s Z8 t stIB JZ t$t ? Zt -} $8 t B P? R${B }BI ? s I$R $t Z$ jsR
=t wtB stD `B% t 7,kbsj, t%$stIB I R jjBR jZ8$tBRBR I RI j $t $B I RZ {s9s k I RI js RZ} h{$ I j }jst s *s BAsY
=ts ts% R}s{$sj I R}js9? stIBR {Bt s{ j s{$? Bt {BtR st {BtR $ Zk Zt 8s t? h{B jsABT s B $B I st? sj$R$R I j } $t{$}$B I JZ$%sj t{$s 7$ j $t ? }$IB NZ, 7,kbsj, 8$ $ s Zt I R jjB jZ8$tBRB I RI RZ {s9s Z8AB sj $tY? BR}$ B }jst s *s BAsY js sk { B $s I j Ys9 }s { ? s {Z %s R %$R B I RI j $t $B I js ts% }B P { B I RZ s{ j s{$? Bt
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
nd
VR? j }Zt B I {Bt s{ B {Bt js }s I B}Z R s I js ts% R s ? s R$ ZsIB }B I As`B I j t$% j I RI j JZ }s $? B j Ys9 ej } $t{$}$B I JZ$%sj t{$s RBR $ t JZ j skB I A ? s s8A$? t {Z %s R t } R t{$s I Zt {s8}B s%$ s B $B {B8B js RZ} h{$ I j }jst s *s BAsY 7$ js s{ j s{$? Bt I js ts% {B$t{$I$ s {Bt j %sjB I js s% IsI I *s BAsY jsR sk { B $sR I R{ $ sR }B s8ABR skBR I jZ9 RZj s ? st $tI$R $t Z$Aj R Ns sk { B $s I Zt skB I jZ9 I$AZ`s j R}s{$BT $ 8}B }B {BtR$ Z$ t js } R t{$s I Zts 8sRs I PB 8s js } B}$s R Z{ Z s I j R}s{$BT $ 8}B Ns tZ %s B ? s I js s% IsI } B}Z R s }B e$tR $t } 8$ ? s -}j${s jsR } {Zj$s $IsI R I j 8B%$8$ t B I {Z $B } B $t BIZ{? s Zts Rs s I {B8}j `$IsI R {B8B jBR s Z` BR t BR jBR s Z` BR I ZRstB k js }BR$A$j$IsI I j %$s` t j $ 8}B 7$t IZIs js $I s I JZ js sk { B $s I R{ $ s }B Zt skB I jZ9 R {Z %sAs t } T R t{$s I Zts 8sRs {sZR? B Zts } BPZtIs {Bt8B{$? Bt t js {B8Zt$IsI {$ t ? h{s *${Ys } I${{$? Bt PZ {B BAB sIs -} $8 t sj8 t t d d }B j sR ? BtB8B A $ ? st${B V YZ 7 eII$t Bt wdMM1Td ;;D IZ st Zt {j$}R B sj I 7BjU j {s8}B s%$ s B $B I j 7Bj } BIZ{? s Zts I R%$s{$? Bt I R? BjB d R ZtIBR I s {B ej I R}js9s8$ t B st Zjs I js }BR${$? Bt I Zts R jjs I A$IB s R P { B R ZtsR d ((( % { R $tP $B sj s8sK tB s}s t I j I$R{B RBjs =t P { B JZ } R s R 8$t? ZR{ZjB {Bth 8sAs jsR R$R I e$tR $t ,
Vj ZtBR sZ B R Yst RZ $IB JZ js 8 s -$R t{$s I Zts R$t Zjs $IsI t j $t $B I Zt s Z` B t B {BtR $ Zk Zts }Z s sA$ s s B sR $Bt R I j Zt$% RB *${Ys Y$}? B R$R R 4 `s t Zts s8}j$s %s $ IsI I tB% jsR k } j? {ZjsR I j ? t B ; {B8B k $ >d EMH I _BZj VtI RBt Ns Z s $t 8$tsAj I FB <sjI 8st _? B ${B >ps bsk d H I 3 I $, _BYj q$ s >es Y d (H I *s%$I $t B j hj8 ej sA$R8B t B >qY js{, <Bj d H _ R s JZ sj ZtBR R ZI$BR Yst RZ $IB js }BR$Aj {Bt -$? Bt t s Z` BR t BR t B s{$? Bt k 8? sJZ$tsR I j $ 8}B js %$sA$j$IsI I sj R {Bt` Z sR }s { YBk I? s I R{s sIs ! B I$R}BR$ $%B {Bt{ A$IB t j {Bt - B I js js $%$IsI t sj k {Bt }B t{$sj R s}j${s{$Bt R }s s j %$s` t j $ 8}B R j jjs8sIB {$j$tI B I q$}j _ B}Z R B }B j {Bt B% $IB P? R${B 3 st, F q$}j t d ; R AsRs t Zt {$j$tI B $tht$ B Zj sI tRB k t ? s}$Is B s{$? Bt w{Bt Zts % jB{$IsI t js } $P $s I j {$j$tI B I js 8$ sI I js % jB{$IsI I js jZ9 }s s {B8} tRs RZ $t tRs s% IsID JZ } BIZ{$ ? s Zts I PB 8s{$? Bt I js R Z{ Z s R}s{$BT 8}B sj ej P? R${B FBYt p $AA$t Ys RZ $IB JZ Zt {$j$tI B RZh{$ t 8 t js B {Bt Zt {B{$ t t jBt $ ZI k sI$B I j B I t I d( }BI ? s } BIZ{$ P { BR st? sjB BR et s8ABR {sRBR j I R}js9s8$ t B s jB js B I j {$j$tI B } 8$ $ ? s j %$s` t j $ 8}B st B Ys{$s j PZ Z B {B8B Ys{$s j }sRsIB w{Bt js Z ?t${s R ${{$? Bt I I R $tBR }BR $B R s js P {Ys I {BtR Z{{$? Bt I j {$j$tI BD 7 Yst sj9sIB sj ZtsR %B{ R { ? ${sR {Bt s js %$sA$j$IsI I jBR {$j$tI BR I q$}j Z $j$9sIBR }B _BZj et "qB8B Bb $R O R Isk" >d E H }$RBI$B I js R $ I j %$R$? Bt Ns {BtJZ$R s I j R}s{$B js ts% et } $R R t%$sIs s js q$ s I j R$ jB sR j t{Z t B PB Z$ B {Bt Zts R jjs t s ej ? 8$tB s Z` B t B YsA? s R$IB s{ZK tsIB }B j P? R${B FBYt V GY j R? BjB ZtBR 8 R R st R I js 8$R$? Bt I j }$RBI$B k RZ s{ } s{$? Bt 8? sR sjj? s I j s ?8A$ B {$ t ? h{B s I? B sj ? Zt $ 8}B t { $R sj$9s 1;
© Los autores, 2001; © Edicions UPC, 2001.
ndM
* $t Bt s e$tR $t
VtI RBt t ej s%s s >qY V%s s d MH wIBtI R ts s js -$R t{$s I $ st R{BR {$j$tI BR jsR I tB8$tsIsR ? sJZ$tsRTq { sIsR }B Zts s9s sj$ t? ts st{ R sj k JZ R t{Z t st I$R} RsR }B j R}s{$B s I$R}BR${$? Bt I JZ$ t jsR R }s Ys{ PZt{$Bts D k }B Ns k W$% t t RZ js B iB s $t ]$j$tI R stI Y _BRR$A$j$ k BP pjBAsj ]sZRsj$ k z$Bjs $Bt et jBR } BAj 8sR s}Zt sIBR R {Z t s js sj ? R$8s I tR$IsI JZ $Is }s s js {BtR Z{{$? Bt I j {$j$tI B gRZ} $B t 8? sR I ;( B ? I t R I 8s t$ ZI s js I tR$IsI I js 8s $s tZ{j s WB R {BtB{ wt$ R {Bt{$A D Zt 8s $sj {Bt Zts I tR$IsI }s {$Is qs8}B{B -$R t 8s $sj R JZ } 8$ st R$R $ jsR tR$Bt R - 8sR } BIZ{$IsR }B js ? s}$Is B s{$? Bt I j {$j$tI B ]Bt Zt sI$B I d( ,8 k Zts jBt $ ZI I d(( ,8 R JZ $ ? s Zts s{ j s{$? Bt { t ? } s 1(( ((( 8$jjBt R I % { R 8skB JZ js s% IsI R }s s } BIZ{$ js % jB{$IsI I B s{$? Bt JZ $Is *sIs RZ st 8sRs R Ys s}Zt sIB js }BR$A$j$IsI I JZ j {$j$tI B 8} 9s s s {Bjs}Rs st R I {B8}j s R RZ {BtR Z{{$? Bt ej Z ?j $8B RjsA? Bt I js {sI ts JZ R $t${$s {Bt js }ZAj${s{$? Bt I js B ? s I js js $%$IsI t sj k JZ {Zj8$ts {Bt js PB 8Zjs{$? Bt I RBjZ{$Bt R JZ {Bt 8}jst j %$s` s s%? R I j $ 8}B jB {BtR $ Zk t jBR s Z` BR I ZRstB _ R s RZ js s sI${$? Bt t j 8ZtIB I js P? R${s wPZ Bt $t BIZ{$IBR }B NZIb$ 3js88 t d dED RZR } R s{$Bt R {B8B 8? sJZ$ts I j $ 8}B R? BjB Yst R$IB $tR$tZsIsR ? 8$Is8 t s }s $ I js }ZAj${s{$? Bt I js tB% js ]Bt s{ B I ]s j 7s st k I jBR R ZI$BR jj %sIBR s {sAB }B $} qYB t k {BjsAB sIB R p[ BI j } B}ZRB js B s{$? Bt I j Zt$% RB sRjsI? B s jBR 8 s $BR %$s` BR I j $ 8}B s jsR { {st? sR I Zt s Z` B t B t B s{$? Bt k q$}j IZ`B j } BAj 8s s js B s{$? Bt I Zt {$j$tI B $tht$ B ej 8BI jB I qYB t k B $R }s I js } 8$Rs I JZ t Zt R}s{$BT $ 8}B {Z %B -$R t I$% RsR 8st sR I {Bt { s IBR }Zt BR I PB 8s JZ }Z I Ysjjs R Zt {s8$tB 8? sR {B B JZ js 8 s j? t s { s *${YBR ? Zt j R PZ Bt AsZ $9sIBR }B j P? R${B FBYt V GY j {B8B s Z` BR I ZRstB Z $j$9stIB j R? 8$j JZ } B}B {$Bts j Zt$% RB RP? ${B I Zts 8st9sts IBtI j 8B%$8$ t B R $t $IB s jB js B I RZ RZ} h{$ }BI ? s s{B s R Z $j$9stIB Zt ? Zt j s RZ s%? R {B8B j { sIB }B Zt $tRs{$sAj ZRstB NBR s Z` BR I ZRstB Yst sR}sRsIB js As s JZ R }s s {$ t{$s k h{{$? Bt $ Z8}$ tIB {Bt PZ 9s t I$% RsR { s{$Bt R I j ? t B sjZs I Zt {Z RB t sj9s j s Z` B As`B $stB I js R $ I j %$R$? Bt eR}s{$B } BPZtIB tZ % >7 s q ,U * } 7}s{ W$t d nT H Ys IsIB }$ s $ttZ8 sAj R $t {s8A$BR {B8 {$sj R t I$% RBR R { B R I js psjs-$s JZ Z $j$9st R {Z $BRB {B IB R}s{$B 8}B sj t RZR I R}js9s8$ t BR ! sR R $ R }s sj jsR RZ $IsR t B tB sj P t? B8 tB RB{$Bj? B ${B q , {B8B 7 s q ,U js tZ %s t s{$? Bt B 7 s q ,U zBks Yst {Z $IB B{sR$Btsj8 t s R {Z RB Y? A $IB t sj$IsI k JZ$8 s VZtJZ PZ ]s j 7s st JZ$ t RZR{$ ? B j 8skB %Z jB I RI Zt }Zt B I %$R s P? R${B sR js }ZAj${s{$? Bt I RZ tB% js ]Bt s{ B IBtI Zts 8$R $BRs {$%$j$9s{$? Bt }Bt t 8stBR I js YZ8st$IsI js {tBjB ? s }s s { Z9s js psjs-$s I PB 8s {ZsR$ $tR st ? st s s s%? R I sj R PB 8$IsAj R s s`BR ej 8BI jB } B}Z R B }B $} qYB t k ${Ys j B $R }s s RB s j sA$R8B $tRBtIsAj JZ R }s s j 7$R 8s 7Bjs I js R jjs z s $8s $ts Zt s Z` B I ZRstB R ? s ${B I s8sK tB h`B k {BtR$R t {Bt js js $%$IsI t sj 5+Z? sR} { B I A ? s t I${YB s Z` B I ZRstB2 et j 8BI jB I qYB t k B $R ? R sIB} s PB 8s I jB` I s ts {Bt IBR RP sR s j ? stR$ B I {Bt { sIsR 8 I$st Zts s st s R {Ys w3$ E ddD Ns s st s } 8$ $ ? Y$}B ? ${BR %$s` BR $t R js R I Zt }Zt B I j Zt$% RB s B B NBR - 8BR I j jB` I
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
nd
]ZsI B E ; p s% IsI k $ 8}B Ns I$P t{$s t jBR $ 8}BR 8 I$IBR }B Zt BAR %sIB R$ ZsIB t j $tht$ B sj BAT R %s 1 jB` R ZtB `Zt B s RZ }BR${$? Bt k B B RBA js RZ} h{$ I Zt I 8$tsIB }jst s B R jjs %$ t IsIs }B js js{$? Bt q$ 8}Bw}jst sD ) q$ 8}Bw$tht$ BD wd d!;M d( sRsbisI$BDd>1 _s s j {sRB I js q$ s -$R Zts I$P t{$s 8$t? ZR{Zjs t s8ABR $ 8}BRU t d E( iBA z _BZtI k RZR R ZI$st R p B V i A,s k F N 7t$I jj %s Bt s {sAB Zt -} $8 t B t js =t$% R$IsI I <s %s I }s s 8 I$ j P { B I js s% IsI R t j 4Z`B I j $ 8}B 7ZR RZj sIBR {Bt{Z Ist R t{$sj8 t {Bt jsR } I${{$Bt R % $IsR }B js js $%$IsI t sj _s s j 7Bj j {B{$ t I $ 8}BR R I (, M { {stB s js Zt$IsI VR? R JZ$ t {s8}BR s%$ s B $BR 8Z{YB 8? sR $t tRBR }s s } BIZ{$ P { BR tB sAj R et R R t $IB }s { $t{ ? Aj JZ } j? {ZjsR {B8B 7 s q , yz $R$? BtU Rsj%s js q$ s >7 s q , yzU qY zBks <B8 d MEH B }$RBI$BR I js R $ {j? sR${s {B8B "qB8B Bb $R O R Isk" >d E H Z $j${ t j 7Bj {B8B {s s}Zj s s%$ s B $s }s s %$s`s t j $ 8}B !A` BR {Bjs}RsIBR {B8B jsR R jjsR I t Z Bt R } 8$ t 8BR s BR tR$Aj R I$P t{$sR _s s Zts R jjs I t Z Bt R I 1 8sRsR RBjs R k d( ,8 I sI$B j {B{$ t I $ 8}BR R IZ{ s (, E; 7? BjB Zt s Z` B t B {BtR $ Zk Zt R{ ts $B 8? sR I s8? s ${B * Y {YB sj s} B-$8s Zt jB` s Zts I$R st{$s I j { t B I j s Z` B IsIs }B i7 ) d3;M d( 1 sRs I tB8$tsIs sI$B I 7{Ybs R{Y$jI j $ 8}B }s { {Bt js R U j jB` $t%$ Zt $ 8}B $tht$ B t { Z9s I${Ys P Bt s =t sR BtsZ s JZ R } {$}$ s s RBA Zt s Z` B t B s s? IB $8}js{sAj 8 t }B RZ $t tRs s% IsI s}s { ? s h`B t js }BR${$? Bt I ht$Is }B j sI$B I 7{Ybs 9R{Y$jI IZ st Zt $ 8}B $tht$ B WZt{s {BtR Z$ ? s8BR s} {$s j 8? sR 8? t$8B s%st{ t RZ {s? Is _B{B I R}Z? R I RZ }ZAj${s{$? Bt t d dE js B ? s I js js $%$IsI t sj k RZR $8}j$T {s{$Bt R RBA js ts Z sj 9s I j R}s{$BT $ 8}B 8} 9s Bt s } t s t j R tB I js {$ t{$s h{{$? Bt s}B stIB tZ %BR s Z8 t BR {Bt JZ `ZR $h{s j %$s` t j $ 8}B qY GB jI jBb >d n(H I 7 3Bbj G $ Y I$R{Z ks Zt 8 {st$R8B I I R}js9s8$ t B 8}B sj AsRsIB t js {Z %s Z s I j R}s{$BT $ 8}B et qY q$8 FZ8} R >d ExH I _ 3 WBjst Zt {$ t ? h{B I R{ZA Zt - sK tB 8s $sj j IBA$t$Z8 JZ AB8As I sIB {Bt jBR skBR 8$ $IBR }B Zt - sK tB I$R}BR$ $%B } 8$ $t% $ js {Z %s Z s I j R}s{$BT $ 8}B gk %$s`s sj }sRsIB qs8A$? t _BZj VtI RBt Ys{ P t{$s sj {? sj{ZjB tRB $sj k s PZ 9sR tTI$8 tR$Btsj R }s s sj s js {Z %s Z s I j R}s{$BT $ 8}B t RZ js B qY N$ j BtR >d nH }Zt BR I t sIs k Rsj$Is I j s Z` B I A ? st R }jstBR I s{Z IB {Bt js $I s I JZ j R}s{$BT $ 8}B R }jstB t sZR t{$s I 8s $s * js 8$R8s 8st s js s st s I j s Z` B I A ? s {Bt t st {st $IsI I 8sRs }s s 8BI js sj sIB I {Z %s Z s et j I$R K tB I Zt s Z` B I ZRstB stR$ sAj R JZ$ sR$8$R8B JZ ? R tB R{BtIs t$t ? Zt s ts
© Los autores, 2001; © Edicions UPC, 2001.
n1(
* $t Bt s e$tR $t
YB $9Bt I RZ{ RBR t RZ $t $B JZ j$8$ j s{{ RB s $Bt R I tB B tB _B JZ 5JZ? Z $j$IsI tI ? s Zt s Z` B I ZRstB I j JZ tB }ZI$ s %Bj% R 2 * j 8$R8B 8BIB I A } 8$ $ j {? B8BIB s{{ RB s jBR %$s` BR k %$ s jsR $ ? st${sR 8s sR s%$ s B $sR JZ ? R BR }BI ? st -} $8 t s s RZ }sRB =t sR} { B R t{$sj t j I$R K tB I Zt s Z` B I ZRstB R RZ R sA$j$IsI i RZj s {B8}j `B s% t Z s j Y$}B ? ${B I R $tB I $tPB ZtsIBR %$s` BR JZ 8ZjstIB s jBR $}Zjst R I js ts% P t $ I "ej } {$B" >qY _ $t{ d M H ZtB I jBR }$RBI$BR I 7 s q ,U js tZ %s t s{$? Bt I Rs}s {$ st I tZ R B Zt$% RB sj I R R sA$j$9s R j s Z` B I ZRstB }B j JZ stR$ st Vj $ Zsj JZ j h{ ${$B ? Zt j R}s{$BT 8}B sj $8s $tsIB }B jBR Z$Bt$R sR I 7 s q , jBR s Z` BR I ZRstB JZ } I${ js P? R${s RBt $t R sAj R 5]? B8B }BI ? s $8} I$ R j {Bjs}RB I Zt s Z` B I ZRstB2 Ns RBjZ{$? Bt s}B sIs }B qYB t k B $R s R s $tJZ$ T st } Zt s {BtIZ{ s $t%B{s js -$R t{$s I 8s $s {Bt Zts I$R $AZ{$? Bt I 8sRsT t ? s t s $%s 8s $s JZ %$Bjs js jjs8sIs {BtI${$? Bt I t ? s I? A$j R ? Zt js {Z? sj BIB {Z }B s{ s s{ $%B I js 8s $sj -$R t t j Zt$% RB }BR 8sRs }BR$ $%s wI s{Z IB {Bt j {s ? PZ 9s s%$ s B $sD ej ZRB I R s 8s $s -? B ${s {BtR $ Zk ZtB I jBR JZ$R$ BR 8? sR R % BR I j 8BI jB I B $R k qYB t qBIsR jsR RBjZ{$Bt R st $B R s jsR {Zs{$Bt R I e$tR $t w j 8BI jB I p[ BI j jBR s Z` BR t BR I B jBR {$j$tI BR I q$}j D RZ t I I$R $AZ{$Bt R I 8s $s {j? sR${s IB sIsR I Zts I$R $AZ{$? Bt I 8sRsT t ? s }BR$ $%s 7$t 8As B js B8 ? s I Zt s Z` B I ZRstB tB 8 I jsR {Zs{$Bt R I e$tR $t As`B js Y$}? B R$R I 8s $s {j? sR${s 5*? BtI }Z I t{Bt s R Zts PZ t I 8s $s -? B ${s IB sIs I Zts I$R $AZ{$? Bt I 8sRsT t ? s t s $%s2 y8s $ts Zts $? Bt $t -}jB sIs I j {BR8BR ABRst I R $}B I 8s $sj t j 7$R 8s 7Bjs }s { sj s8 t $8} BAsAj `B R } R} { $%sR jsR BP { t jBR R$R 8sR JZ $t%BjZ{ st 4Z{ Zs{$Bt R {Z? st ${sR * s{Z IB {Bt j } $t{$}$B I $t{ $IZ8A I < $R tA ZtB I jBR }$js R t JZ R RZR t s js 8 {? st${s {Z? st ${s jBR BA` BR 8${ BR{? B}${BR R ? st IB8$tsIBR }B Zts $8} {$R$? Bt $tY t s js 8 I$Is R$8Zj ? st s I }s R I } B}$ IsI R BAR %sAj R {B8B }BR${$? Bt k % jB{$IsI * s{Z IB {Bt I${YB } $t{$}$B jsR } B}$ IsI R I jBR BA` BR 8${ BR{? B}${BR R$ 8} 4Z{ ? Zst Os t d ;M j P? R${B YBjstI? R < tI $, ]sR$8$ {Bt{$A$? B Zt -} $8 t B }s s 8 I$ jsR 4Z{ Zs{$Bt R {Z? st ${sR I j %s{? B JZ } I${ js B ? s {Z? st ${s ]sR$8$ } B}ZRB JZ IBR }js{sR 8 ? sj${sR }jstBT}s sj jsR {s sIsR k R$ ZsIsR s {B s I$R st{$s I A ? st ` { R PZ 9sR j? { ${sR et sZR t{$s I {s s tB I A ? st 8BR s $t s{{$? Bt j? { ${s sj Zts 7$t 8As B {BtR$I stIB jsR 4Z{ Zs{$Bt R {Z? st ${sR I j %s{? B s? Zt t sZR t{$s I {s s s8AsR }js{sR I A ? st ` { R Zts PZ 9s 8Z Zs JZ sZtJZ } JZ K ts }BI ? s 8 I$ R NBR RZj sIBR -} $8 t sj R I A$IBR s ]sR$8$ PZ 9st js R$R I JZ I${YsR 4Z{ Zs{$Bt R I j %s{? B }BI ? st $t } s R {B8B I A$IsR s Zts I$R $AZ{$? Bt I 8sRs t s $%s =t jZ s I j JZ }BI ? s - s R 8s $s -? B ${s R Zt s Z` B t B et RZR } B-$8$IsI R R I A t } BIZ{$ {Bt $tZsR PB 8s{$Bt R k st$JZ$js{$Bt R I }s R }s ? {ZjsTst $}s ? {Zjs JZ 8 t I j %s{? B {Bt Zts t ? s 8 I$s tZjs eR RZj sIB JZ$ JZ ZtB I jBR {B8}Bt t R I j }s }BR s t ? sT8sRs }BR$ $%s 8$ t sR JZ j B B }BR s t ? sT8sRs t s $%s 7Z}Bt s8BR JZ j 8$ 8A B {Bt t ? s }BR$ $%s R s s}sIB }B jsR I R s%$ s B $sR I j s Z` B t B * RI j - $B j P { B t B R ? s js 8$R$? Bt I Zts }s ? {Zjs } B{ I t I j s Z` B t B ej P? R${B 7 }Y t G <sb,$t I R$ t? B I${YB P t? B8 tB {B8B js %s}B s{$? Bt I j s Z` B t B _BI ? s8BR {Bt{ A$ sj ? Zt sR Z B 8 {st$R8B }s s s s}s js {B8}Bt t t s $%s I j }s q tI ? s8BR I R s 8st s Zts PZ t ts Z sj I 8s $s -? B ${s WB BAR st j 8s $sj I A Rs $RPs{ B sR {BtI${$Bt R {B8B Zts $ $I 9
© Los autores, 2001; © Edicions UPC, 2001.
E pZ? s }s s %$s` BR I j $ 8}B
n1d
3$ E dd i } R t s{$? Bt RJZ 8? s ${s I j ? Zt j R}s{$BT 8}B sj {Bt{ A$IB }B $} qYB t k ${Ys j B $R ZjB t d ED k ZRsIB }B ]s j 7s st t RZ tB% js ]Bt s{ B >]Bt s{ d MxH wsIs} sIs sj {$t {Bt j 8$R8B ? }s s RB s j j? 8$ $8}Z R B }B js % jB{$IsI I js jZ9 t j %$s` I Zts ts% R YsR s js I$R st R jjs z s t js {BtR js{$? Bt I js N$ s - 8s }s s $8} I$ j {Bjs}RB I js s st s qYB t k B $R Yst R $8sIB js tR$? Bt Bt 8? t$8s I j 8s $sj t ZtsR d(@N % { R js I tR$IsI I j 8s $sj Z $j$9sIB t js {BtR Z{{$? =t } BAj 8s s% IsIB JZ js 8skB ? s I jBR 8s $sj R {BtB{$IBR } R t st tR$Bt R I Z} Z s }B{B 8skB R JZ RZ I tR$IsI ! BR 8BI jBR I s Z` B I ZRstB Yst %$R B js jZ9 I RI js s}s ${$? Bt I j sAs`B I B $R k qYB t s z$RR I js =t$% R$IsI I GsRY$t Bt t 7 NBZ$R Ys {BtR Z$IB IZ{$ js {st $IsI I 8s $s -? B ${s JZ $Is }B j 8BI jB I qYB t T B $R $t BIZ{$ tIB Zt 8BI jB I s Z` B I ZRstB tB RP? ${B Zts R} {$ I ABA$ts I Y$jB {Zks s st s R ? s {BtT R $ Z$Is }B }s I R {Bt s ?t ZjBR { BR JZ } 8$ t sZ8 t s js R sA$j$IsI I js R Z{ Z s VR$8$R8B j 8BI jB I z$RR {BtR$ Z IZ{$ j sj{st{ I jsR PZ 9sR I 8s s t j $t $B I j s Z` B =t Y$}B ? ${B %$s` B JZ R s{ {s s s Zt s Z` B I ZRstB {B8B j {Bt{ A$IB }B z$RR }BI ? s s ${Zjs P sR R R 8 `st R s jsR } BtZt{$sIsR }B j sR BtsZ s *s%$I Bb8st JZ$ t t j 8? R ${B htsj I js tB% js 1((d Zts BI$R s I j R}s{$B >1((dU V 7}s{ !IkRR k d EMH I V YZ ] ]js , R % s sR sIB sj B B - 8B I js psjs-$s s s%? R I Zts }Z s R js U "gej BA` B R YZ {B k R$ Z k R$ Z k BY *$BR 8? B R ? s jj tB I R jjsR " sh 8s st js {Bt 8}js{$? Bt I Zt } $R8s { st Zjs j$RB k I stI R I$8 tR$Bt R _B{B I R}Z? R Bb8st R } {$}$ s }B j BR{Z B ? Zt j {sk tIB Ys{$s sJZ jjsR R jjsR $8}BR$Aj R 8$ t sR 8 8B s %$ `sR B ? sR RBA j Y$} R}s{$B k RBA {BtIZ{ BR $I$8 tR$Btsj R
© Los autores, 2001; © Edicions UPC, 2001.
n11
* $t Bt s e$tR $t
WB R {BtB{ BIs%? s Zts B ? s I ht$ $%s JZ Zt$hJZ js s% IsI k j $tB I js P? R${s {Z? st ${s t js R{sjs I js jBt $ ZI I _jst{, d( nn {8 IBtI {B8B RBR $ t j } $t{$}$B I $t{ $IZ8A I < $R tA j R}s{$BT $ 8}B I A ? s }s { AB BRB V I${Ys R{sjs j Zt$% RB R s ? s PB 8sIB }B Zts R}Z8s R}s{$BT 8}B sj Zt 8s I B8 ? s Z AZj t s {Bt 8? Zj $}j R {Bt -$Bt R {Bt s Z` BR I ZRstB 8${ BR{? B}${BR JZ }BI ? st }B t{$sj8 t 8st$}Zjs R k s stIs R _ R s jsR } B8 IB sR } R} { $%sR JZ BP { js PB 8Zjs{$? Bt I jBR s Z` BR I ZRstB jBR I P tRB R s{? $8BR I j %$s` t j $ 8}B tB Yst t{Bt sIB BIs%? s Zts B ? s sZ B{BtR$R t s js JZ sP s R {$ s8 t WB -$R t } Z AsR -} $8 t sj R I js -$R t{$s I s Z` BR I ZRstB t$ R$JZ$ s I jsR %s $ IsI R 8${ BR{? B}${sR 8 t R I js Z AZj t s R}Z8s R}s{$BT 8}B sj NsR }BR$A$j$IsI R I 8st$}Zjs{$? Bt I Zt s Z` B I ZRstB R{s}st s8A$? t I BIs - s}Bjs{$? Bt {tBj? B ${s W$ R$JZ$ s }BI 8BR {Zst $h{s j $ 8B I } BIZ{{$? Bt I 8s $s -? B ${s $tI$R} tRsAj }s s RZ R sA$j$IsI qs8}B{B B BR 8BI jBR I 8? sJZ$ts I j $ 8}B {B8B j 8BI jB I pB AsRsIB t j I R}js9sT 8$ t B I IBR {Z IsR {? BR8${sR t R t $IB {Bt s $B1x B j 8BI jB I AZ AZ`s I VYs BtB% AsRsIB t js sj s{$? Bt I j {s8}B s%$ s B $B sj {Bt s B I$js s Zts RP s }s { t s}B s tZ %s jZ9 s jBR } BAj 8sR $tY t R sj R B I 8BI jBR } B}Z R BR Ns js $%$IsI t sj t {Zst B $t{B8}s $Aj {Bt js 8 {? st${s {Z? st ${s {BtR $ Zk Zts B ? s $t{B8}j s 7 Ys s Z8 t sIB JZ js 8 s -$R t{$s I R$t Zjs $IsI R {B8B t j $t $B I Zt s Z` B t B B js PB 8Zjs{$? Bt I RBjZ{$Bt R JZ }s { t } 8$ $ j %$s` t j $ 8}B {BtR $ Zk t 8Z R sR I js } B}$s j$8$ s{$? Bt I js B ? s et }sjsA sR I j P? R${B Vjst N$ Y 8stU "i RZj s $8}BR$Aj t{Bt s RBjZ{$Bt R {Bt{ sR s jsR {Zs{$Bt R I e$tR $t JZ } 8$ st j %$s` t j $ 8}B k s js % 9 R {B8}B t A$ t t B BR sR} { BR qBIsR jsR } B}Z R sR B A$ t JZ$ t Zts {Bth Z s{$? Bt I 8s $s $ts{ } sAj B }BR t {B8B 8? t$8B Zt }Zt B }s ${Zjs 8 t tsZR sT AZtIB t j R}s{$B jjs8sIB R$t Zjs $IsI JZ ks{ PZ s I j IB8$t$B I %sj$I 9 I js B ? s eR {sR$ {B8B R$ js js $%$IsI t sj {ZstIB R s sR sIs Ys{$s RsR {$ {ZtR st{$sR t jsR JZ BIs js P? R${s R $tI R s $t{Y sR $8}jB s s sZ-$j$B" NBR $t t BR I PB 8Zjs Zts B ? s {Z? st ${s I js s% IsI R$ Z t {BtIZ{$ tIB s RBjZ{$Bt R JZ {B8}B st js -$R t{$s I AZ{j R 8}B sj R WB }s { t -$R $ s Z8 t BR P? R${BR I ht$T $%BR JZ %sj$I t B PZ t js %$sA$j$IsI I j %$s` t j $ 8}B _ R s JZ j R t $IB {B8? Zt RZj s R $s8 t {BtP Bt sIB j %$s` }B j $ 8}B t P? R${s {BtR $ Zk BIs%? s Zts } Zt s sA$ s * A 8BR R } ZI t R sj R} { B k tB I `s tBR s sR s }B j t{st B I Zt B st t sIB _BI ? s8BR $t{Z $ t B}$t$Bt R st I ht$ $%sR {B8B jsR % $IsR t js I$ B $sj JZ s{B8}sK tsAs Zt s ? {ZjB I iBA N 3B bs I $ ZjsIB ]? B8B {BtR Z$ Zts 8? sJZ$ts I j $ 8}B >d M(HU "]BtB{ 8BR ks js B ? s NB Z ?t${B JZ Ys{ Psj s R Zt }B{B I $t t$ ? s s%stT 9sIs" Ns R}Z R s I ht$ $%s sj t$ 8s I j %$s` t j $ 8}B I A ? s s Zs Is }BR$Aj 8 t YsR s j I Rs BjjB I Zts B ? s {Z? st ${s I js s% IsI <sR s t Bt{ R "js s k } ? BR} s %$Is " NsR {Z IsR {? BR8${sR {BtR $ Zk t BA` BR ? B ${BR { sIBR IZ st Zts stR${$? Bt I PsR JZ I A$? B t jZ s t j Zt$% RB } $8$ $%B _B {BtR Z{{$? Bt tB -$R t P s 8 t BR I {Z IsR {? BR8${sRU B A$ t {BtR $ Zk t AZ{j R { sIBR B R 8st$h R st t PB 8s I hjs8 t BR R$8}j R k 8Zk js BR et R R t $IB jBR R R A$I$8 tR$Btsj R I "qY NBRR" >d (H }$RBI$B I js R $ I j %$R$? Bt 7 s q ,U js tZ %s t s{$? Bt JZ YsA$ st Zt P s 8 t B I {Z Is {? BR8${s }s { t {s { I BIB R t $IB 1x
© Los autores, 2001; © Edicions UPC, 2001.
“Que la fuerza te acompañe” (La Guerra de las Galaxias, 1979)
fuerza = masa × aceleración (Isaac Newton, 1686)