Two Dimensional Event Set And Its Application In Algebraic Structures

Page 1

JournalofAlgebraicHyperstructures andLogicalAlgebras

Volume1,Number2,(2020),pp.9-21

Twodimensionaleventsetanditsapplicationinalgebraic structures

Y.B.Jun1

1DepartmentofMathematicsEducation,GyeongsangNationalUniversity,Jinju52828,Korea skywine@gmail.com

Abstract

Twodimensionaleventsetisintroduced,anditisapplied toalgebraicstructures.TwodimensionalBCK/BCI-eventful algebra,pairedB-algebraandpairedBCK/BCI-algebraare defined,andseveralpropertiesareinvestigated.Conditions fortwodimensionaleventfulalgebratobeaB-algebraand aBCK/BCI-algebraareprovided.Theprocessofinducinga pairedB-algebrausingagroupisdiscussed.UsingtwodimensionalBCI-eventfulalgebra,acommutativegroupisestablished.

ArticleInformation

CorrespondingAuthor: Y.B.Jun; Received:March2020; Accepted:Invitedpaper.

Keywords: Twodimensionalevent(set), twodimensionalBCK/BCIeventfulalgebra,pairedBalgebra,pairedBCK/BCIalgebra.

1IntroductionandPriliminaries

ThenotionofneutrosophicsetisdevelopedbySmarandache([9],[10]),andisamoregeneralplatform thatextendsthenotionsofclassicset,(intuitionistic)fuzzysetandintervalvalued(intuitionistic)fuzzy set.Smarandache[11]consideredanentry(i.e.,anumber,anidea,anobjectetc.)whichisrepresented byaknownpart(a)andanunknownpart(bT,cI,dF )where T,I,F havetheirusualneutrosophiclogic meaningsand a,b,c,d arerealorcomplexnumbers,andthenheintroducedtheconceptofneutrosophic quadruplenumbers.Neutrosophicquadruplealgebraicstructuresandhyperstructuresarediscussedin.[1] and[2].NeutrosophicquadrupleBCK/BCI-algebraisstudiedin[5]and[7].Usingneutrosophicquadruple structures,Junetal.[4]introducedthenotionofeventsbyconsideringtwofacts,andapplieditto BCK/BCI-algebras.Therearemanythingsinourdailylivesthatwehavetochoosebetweentwofacts. Forexample,shouldIreadabookornot,gotothemoviesornot,etc.Toconsiderthesetwofactors, weintroducetwo-dimensionaleventsetsandtrytoapplythemtoalgebraicstructures.Weintroducethe notionsoftwodimensionalBCK/BCI-eventfulalgebra,pairedB-algebraandpairedBCK/BCI-algebra, andinvestigateseveralproperties.Weprovidedconditionsfortwodimensionaleventfulalgebratobea B-algebraandaBCK/BCI-algebra.WediscusstheprocessofinducingapairedB-algebrausingagroup, andestablishacommutativegroupusingtwodimensionalBCI-eventfulalgebra.

https://doi.org/10.29252/HATEF.JAHLA.1.2.2

Wedescribethebasiccontentsthatwillbeneededinthispaper.Let(X, ∗, 0)beanalgebra,i.e.,let X beasetwithaspecialelement“0”andabinaryoperation“∗”,andconsiderthefollowingconditions.

(∀u ∈ X)(u ∗ u =0). (1)

(∀u ∈ X)(u ∗ 0= u). (2)

(∀u ∈ X)(0 ∗ u =0). (3)

(∀u,v,w ∈ X)((u ∗ v) ∗ w = u ∗ (w ∗ (0 ∗ v))). (4)

(∀u,v ∈ X)(u ∗ v =0,v ∗ u =0 ⇒ u = v). (5)

(∀u,v ∈ X)((u ∗ (u ∗ v)) ∗ v =0). (6) (∀u,v,w ∈ X)(((u ∗ v) ∗ (u ∗ w)) ∗ (w ∗ v)=0). (7)

Wesaythat X :=(X, ∗, 0)is

• a B-algebra (see[8])ifitsatisfies(1),(2)and(4),

• a BCI-algebra (see[6])ifitsatisfies(1),(5),(6)and(7),

• a BCK-algebra (see[3])ifitisaBCI-algebrasatisfying(3).

ABCI-algebra X :=(X, ∗, 0)issaidtobe p-semisimple (see[3])ifitsatisfies: (∀u ∈ X)(0 ∗ (0 ∗ u)= u) (8)

2Twodimensionaleventsets

Definition2.1. Let ℓ : X → Q beamappingfromaset X toaset Q.Forany a,x ∈ X,theorderedpair (x,ℓa) iscalledatwodimensionaleventon X where ℓa istheimageof a under ℓ

Thesetofalltwodimensionaleventson X isdenotedby(X,ℓX ),thatis, (X,ℓX )= {(x,ℓa) | x,a ∈ X} (9) anditiscalleda twodimensional X-eventset. Bya twodimensional X-eventfulalgebra wemeanatwo dimensional X-eventsetwithabinaryoperation&,anditisdenotedby ⟨(X,ℓX ), &⟩ Let ⟨(R,ℓR), ⊕⟩, ⟨(R,ℓR), ⊖⟩ and ⟨(R,ℓR), ⊙⟩ betwodimensional R-eventfulalgebrasinwhich“⊕”,“⊖” and“⊙”aredefinedasfollows:

(x,ℓa) ⊕ (y,ℓb)=(x + y,ℓa+b), (x,ℓa) ⊖ (y,ℓb)=(x y,ℓa b), (x,ℓa) ⊙ (y,ℓb)=(x y,ℓa b), respectively,foranytwodimensionalevents(x,ℓa)and(y,ℓb)on R.Forany t ∈ R andatwodimensional event(x,ℓa)on R,wedefine t(x,ℓa)=(tx,ℓta) (10) Inparticular,if t = 1,then 1(x,ℓa)=( x,ℓ a)and 1(x,ℓa)issimplydenotedby (x,ℓa).

Proposition2.2. Let ⟨(R,ℓR), ⊕⟩, ⟨(R,ℓR), ⊖⟩ and ⟨(R,ℓR), ⊙⟩ betwodimensional R-eventfulalgebras. Then

(i) ((x,ℓa) ⊕ (y,ℓb)) ⊕ (z,ℓc)=(x,ℓa) ⊕ ((y,ℓb) ⊕ (z,ℓc)), (ii) (x,ℓa) ⊕ (y,ℓb)=(y,ℓb) ⊕ (x,ℓa), (iii) (x,ℓa) ⊙ (y,ℓb)=(y,ℓb) ⊙ (x,ℓa),

10 Y.B.Jun

(iv) ((x,ℓa) ⊙ (y,ℓb)) ⊙ (z,ℓc)=(x,ℓa) ⊙ ((y,ℓb) ⊙ (z,ℓc)),

(v) t((x,ℓa) ⊕ (y,ℓb))= t(x,ℓa) ⊕ t(y,ℓb) forall t ∈ R,

(vi) (t + s)(x,ℓa)= t(x,ℓa) ⊕ s(x,ℓa) forall t,s ∈ R, (vii) (x,ℓa) ⊕ ( (x,ℓa))=(0,ℓ0). (viii) (x,ℓa) ⊙ (x,ℓa) 1 =(1,ℓ1) where (x,ℓa) 1 =(x 1,ℓa 1 ) foralltwodimensionalevents (x,ℓa), (y,ℓb) and (z,ℓc) on R

Proof. Straightforward.

ByProposition 2.2,wehavethefollowingtheorem. Theorem2.3. Twodimensional R-eventfulalgebras ⟨(R,ℓR), ⊕⟩ and ⟨(R,ℓR), ⊙⟩ arecommutativegroups withidentities (0,ℓ0) and (1,ℓ1),respectively.

3Twodimensionaleventfulalgebras

Let(X, ∗, 0)beanalgebraand ⟨(X,ℓX ), ⊛⟩ beatwodimensional X-eventfulalgebrainwhich“⊛”isdefined by (x,ℓa) ⊛ (y,ℓb)=(x ∗ y,ℓa∗b) respectively,forall x,y,a,b ∈ X.Inatwodimensional X-eventfulalgebra ⟨(X,ℓX ), ⊛⟩,theorder“≪”is definedasfollows:

(x,ℓa) ≪ (y,ℓb) ⇔ x ≤ y and a ≤ b forall x,y,a,b ∈ X where x ≤ y means x ∗ y =0and a ≤ b means a ∗ b =0. Theorem3.1. If (X, ∗, 0) isaB-algebra,thenthetwodimensional X-eventfulalgebra ⟨(X,ℓX ), ⊛⟩ isa B-algebrawiththespecialelement (0,ℓ0).

Proof. Forany(x,ℓa), (y,ℓb), (z,ℓc) ∈ (X,ℓX ),wehave (x,ℓa) ⊛ (x,ℓa)=(x ∗ x,ℓa∗a)=(0,ℓ0),(x,ℓa) ⊛ (0,ℓ0)=(x ∗ 0,ℓa∗0)=(x,ℓa), and ((x,ℓa) ⊛ (y,ℓb)) ⊛ (z,ℓc)=(x ∗ y,ℓa∗b) ⊛ (z,ℓc) =((x ∗ y) ∗ z,ℓ(a∗b)∗c) =(x ∗ (z ∗ (0 ∗ y)),ℓa∗(c∗(0∗b))) =(x,ℓa) ⊛ (z ∗ (0 ∗ y),ℓc∗(0∗b)) =(x,ℓa) ⊛ ((z,ℓc) ⊛ (0 ∗ y,ℓ0∗b)) =(x,ℓa) ⊛ ((z,ℓc) ⊛ ((0,ℓ0) ⊛ (y,ℓb))) by(1),(2)and(4),respectively.Therefore ⟨(X,ℓX ), ⊛⟩ isaB-algebrawiththespecialelement(0,ℓ0).

Wesaythat ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩ isa pairedB-algebra Example3.2. Let X = {0,a,b} beasetwiththebinaryoperation“∗”asinTable 1 For Q = {0, 1 2 , 1},defineamapping ℓ asfollows:

ℓ : X → Q,x →    0if x =0, 1 2 if x = a, 1if x = b.

Twodimensionaleventsetanditsapplicationinalgebraicstructures 11

Table1: Cayleytableforthebinaryoperation“∗”

∗ 0 a b 0 0 b a a a 0 b b b a 0 Then (X,ℓX )= {(0,ℓ0), (0,ℓa), (0,ℓb), (a,ℓ0), (a,ℓa), (a,ℓb), (b,ℓ0), (b,ℓa), (b,ℓb)} = {(0, 0), (0, 1 2 ), (0, 1), (a, 0), (a, 1 2 ), (a, 1), (b, 0), (b, 1 2 ), (b, 1)} andtheoperation ⊛ isgivenbyTable 2.Itisroutinetoverifythat ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩ isapairedB-algebra.

Table2: Cayleytableforthebinaryoperation“∗”

⊛ (0,ℓ0)(0,ℓa)(0,ℓb)(a,ℓ0)(a,ℓa)(a,ℓb)(b,ℓ0)(b,ℓa)(b,ℓb) (0,ℓ0)(0, 0)(0, 1)(0, 1 2 )(b, 0)(b, 1)(b, 1 2 )(a, 0)(a, 1)(a, 1 2 ) (0,ℓa)(0, 1 2 )(0, 0)(0, 1)(b, 1 2 )(b, 0)(b, 1)(a, 1 2 )(a, 0)(a, 1) (0,ℓb)(0, 1)(0, 1 2 )(0, 0)(b, 1)(b, 1 2 )(b, 0)(a, 1)(a, 1 2 )(a, 0) (a,ℓ0)(a, 0)(a, 1)(a, 1 2 )(0, 0)(0, 1)(0, 1 2 )(b, 0)(b, 1)(b, 1 2 ) (a,ℓa)(a, 1 2 )(a, 0)(a, 1)(0, 1 2 )(0, 0)(0, 1)(b, 1 2 )(b, 0)(b, 1) (a,ℓb)(a, 1)(a, 1 2 )(a, 0)(0, 1)(0, 1 2 )(0, 0)(b, 1)(b, 1 2 )(b, 0) (b,ℓ0)(b, 0)(b, 1)(b, 1 2 )(a, 0)(a, 1)(a, 1 2 )(0, 0)(0, 1)(0, 1 2 ) (b,ℓa)(b, 1 2 )(b, 0)(b, 1)(a, 1 2 )(a, 0)(a, 1)(0, 1 2 )(0, 0)(0, 1) (b,ℓb)(b, 1)(b, 1 2 )(b, 0)(a, 1)(a, 1 2 )(a, 0)(0, 1)(0, 1 2 )(0, 0)

Proposition3.3. If ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩ isapairedB-algebra,then

(i) (x,ℓa) ⊛ (y,ℓb)=(x,ℓa) ⊛ ((0,ℓ0) ⊛ ((0,ℓ0) ⊛ (y,ℓb))), (ii) ((x,ℓa) ⊛ (y,ℓb)) ⊛ ((0,ℓ0) ⊛ (y,ℓb))=(x,ℓa), (iii) (x,ℓa) ⊛ (z,ℓc)=(y,ℓb) ⊛ (z,ℓc) implies (x,ℓa)=(y,ℓb), (iv) (x,ℓa) ⊛ ((y,ℓb) ⊛ (z,ℓc))=((x,ℓa) ⊛ ((0,ℓ0) ⊛ (z,ℓc))) ⊛ (y,ℓb), (v) (x,ℓa) ⊛ (y,ℓb)=(0,ℓ0) implies (x,ℓa)=(y,ℓb), (vi) (0,ℓ0) ⊛ (x,ℓa)=(0,ℓ0) ⊛ (y,ℓb) implies (x,ℓa)=(y,ℓb), (vii) (0,ℓ0) ⊛ ((0,ℓ0) ⊛ (x,ℓa))=(x,ℓa) forall x,y,z,a,b,c ∈ X Proof. Let x,y,z,a,b,c ∈ X.Then (x,ℓa) ⊛ (y,ℓb)=(x ∗ y,ℓa∗b)=((x ∗ y) ∗ 0,ℓ(a∗b)∗0) =(x ∗ (0 ∗ (0 ∗ y)),ℓa∗(0∗(0∗b))) =(x,ℓa) ⊛ (0 ∗ (0 ∗ y),ℓ0∗(0∗b)) =(x,ℓa) ⊛ ((0,ℓ0) ⊛ ((0,ℓ0) ⊛ (y,ℓb)))

12 Y.B.Jun

whichproves(i).

(ii)Wehave

((x,ℓa) ⊛ (y,ℓb)) ⊛ ((0,ℓ0) ⊛ (y,ℓb))=(x ∗ y,ℓa∗b) ⊛ (0 ∗ y,ℓ0∗b) =((x ∗ y) ∗ (0 ∗ y),ℓ(a∗b)∗(0∗b)) =(x ∗ ((0 ∗ y) ∗ (0 ∗ y)),ℓa∗((0∗b)∗(0∗b))) =(x ∗ 0,ℓa∗0)=(x,ℓa)

(iii)Assumethat(x,ℓa) ⊛ (z,ℓc)=(y,ℓb) ⊛ (z,ℓc).Itfollowsfrom(ii)that (x,ℓa)=((x,ℓa) ⊛ (z,ℓc)) ⊛ ((0,ℓ0) ⊛ (z,ℓc)) =((y,ℓb) ⊛ (z,ℓc)) ⊛ ((0,ℓ0) ⊛ (z,ℓc)) =(y,ℓb).

(iv)Using(i),wehave ((x,ℓa) ⊛ ((0,ℓ0) ⊛ (z,ℓc))) ⊛ (y,ℓb) =(x,ℓa) ⊛ ((y,ℓb) ⊛ ((0,ℓ0) ⊛ ((0,ℓ0) ⊛ (z,ℓc)))) =(x,ℓa) ⊛ ((y,ℓb) ⊛ (z,ℓc))

(v)Supposethat(x,ℓa) ⊛ (y,ℓb)=(0,ℓ0).Then(x,ℓa) ⊛ (y,ℓb)=(y,ℓb) ⊛ (y,ℓb),andso(x,ℓa)=(y,ℓb) by(iii).

(vi)Assumethat(0,ℓ0) ⊛ (x,ℓa)=(0,ℓ0) ⊛ (y,ℓb).Then (0,ℓ0)=(x,ℓa) ⊛ (x,ℓa)=(x,ℓa) ⊛ ((0,ℓ0) ⊛ ((0,ℓ0) ⊛ (x,ℓa))) =(x,ℓa) ⊛ ((0,ℓ0) ⊛ ((0,ℓ0) ⊛ (y,ℓb))) =(x,ℓa) ⊛ (y,ℓb) andso(x,ℓa)=(y,ℓb)by(v). (vii)Wehave (0,ℓ0) ⊛ (x,ℓa)=((0,ℓ0) ⊛ (x,ℓa)) ⊛ (0,ℓ0) =((0 ∗ x) ∗ 0,ℓ(0∗a)∗0) =(0 ∗ (0 ∗ (0 ∗ x)),ℓ0∗(0∗(0∗a))) =(0,ℓ0) ⊛ ((0,ℓ0) ⊛ ((0,ℓ0) ⊛ (x,ℓa))) andso(0,ℓ0) ⊛ ((0,ℓ0) ⊛ (x,ℓa))=(x,ℓa)by(vi).

Weprovideconditionsfortwodimensional X-eventfulalgebratobeaB-algebra. Theorem3.4. Foranalgebra (X, ∗, 0),thetwodimensional X-eventfulalgebra ⟨(X,ℓX ), ⊛⟩ isaB-algebra withthespecialelement (0,ℓ0) ifandonlyifitsatisfies Proposition 3.3(vii) and (x,ℓa) ⊛ (x,ℓa)=(0,ℓ0), (11) ((x,ℓa) ⊛ (z,ℓc)) ⊛ ((y,ℓb) ⊛ (z,ℓc))=(x,ℓa) ⊛ (y,ℓb) (12) forall (x,ℓa), (y,ℓb), (z,ℓc) ∈ (X,ℓX ) Proof. Assumethatthetwodimensional X-eventfulalgebra ⟨(X,ℓX ), ⊛⟩ isaB-algebrawiththespecial element(0,ℓ0).TheconditionProposition 3.3(vii)isbyProposition 3.3.Itisclearthat(11)istruebythe definitionofB-algebra.Also,wehave ((x,ℓa) ⊛ (z,ℓc)) ⊛ ((y,ℓb) ⊛ (z,ℓc))=(x,ℓa) ⊛ (((y,ℓb) ⊛ (z,ℓc)) ⊛ ((0,ℓ0) ⊛ (z,ℓc))) =(x,ℓa) ⊛ ((y,ℓb) ⊛ (((0,ℓ0) ⊛ (z,ℓc)) ⊛ ((0,ℓ0) ⊛ (z,ℓc)))) =(x,ℓa) ⊛ ((y,ℓb) ⊛ (0,ℓ0))=(x,ℓa) ⊛ (y,ℓb)

Twodimensionaleventsetanditsapplicationinalgebraicstructures 13

forall(x,ℓa), (y,ℓb), (z,ℓc) ∈ (X,ℓX ). Conversely,supposethat ⟨(X,ℓX ), ⊛⟩ satisfiesthreeconditions(11),(12)andProposition 3.3(vii).Then (x,ℓa)=(0,ℓ0) ⊛ ((0,ℓ0) ⊛ (x,ℓa)) =((x,ℓa) ⊛ (x,ℓa)) ⊛ ((0,ℓ0) ⊛ (x,ℓa)) =(x,ℓa) ⊛ (0,ℓ0) and ((x,ℓa) ⊛ (y,ℓb)) ⊛ ((0,ℓ0) ⊛ (y,ℓb))=(x,ℓa) (13)

Combining(12)with(13)induces (x,ℓa) ⊛ ((z,ℓc) ⊛ ((0,ℓ0) ⊛ (y,ℓb))) =(((x,ℓa) ⊛ (y,ℓb)) ∗ ((0,ℓ0) ⊛ (y,ℓb))) ⊛ ((z,ℓc) ⊛ ((0,ℓ0) ⊛ (y,ℓb))) =((x,ℓa) ⊛ (y,ℓb)) ⊛ (z,ℓc) forall(x,ℓa), (y,ℓb), (z,ℓc) ∈ (X,ℓX ).Therefore ⟨(X,ℓX ), ⊛⟩ isaB-algebrawiththespecialelement (0,ℓ0).

Theorem3.5. Foranalgebra (X, ∗, 0),thetwodimensional X-eventfulalgebra ⟨(X,ℓX ), ⊛⟩ isaB-algebra withthespecialelement (0,ℓ0) ifandonlyifitsatisfies (11) and (x,ℓa) ⊛ ((((0,ℓ0) ⊛ (y,ℓb)) ⊛ (z,ℓc)) ⊛ (((0,ℓ0) ⊛ (x,ℓa)) ⊛ (z,ℓc)))=(y,ℓb) (14) forall (x,ℓa), (y,ℓb), (z,ℓc) ∈ (X,ℓX )

Proof. Assumethatthetwodimensional X-eventfulalgebra ⟨(X,ℓX ), ⊛⟩ isaB-algebrawiththespecial element(0,ℓ0).Then(11)isvalidinTheorem 3.4.Using(12),weget (((0,ℓ0) ⊛ (y,ℓb)) ⊛ (z,ℓc)) ⊛ (((0,ℓ0) ⊛ (x,ℓa)) ⊛ (z,ℓc)) =((0,ℓ0) ⊛ (y,ℓb)) ⊛ ((0,ℓ0) ⊛ (x,ℓa)). (15)

Itfollowsthat (x,ℓa) ⊛ ((((0,ℓ0) ⊛ (y,ℓb)) ⊛ (z,ℓc)) ⊛ (((0,ℓ0) ⊛ (x,ℓa)) ⊛ (z,ℓc))) =(x,ℓa) ⊛ (((0,ℓ0) ⊛ (y,ℓb)) ⊛ ((0,ℓ0) ⊛ (x,ℓa))) =((x,ℓa) ⊛ (x,ℓa)) ⊛ ((0,ℓ0) ⊛ (y,ℓb)) =(0,ℓ0) ⊛ ((0,ℓ0) ⊛ (y,ℓb)) =(y,ℓb) whichproves(14). Conversely,supposethat ⟨(X,ℓX ), ⊛⟩ satisfies(11)and(14).Ifwesubstitute(y,ℓb)for(x,ℓa)in(14) anduse(11),then (x,ℓa)=(x,ℓa) ⊛ ((((0,ℓ0) ⊛ (x,ℓa)) ⊛ (z,ℓc)) ⊛ (((0,ℓ0) ⊛ (x,ℓa)) ⊛ (z,ℓc))) =(x,ℓa) ⊛ (0,ℓ0) (16) Ifweput(x,ℓa)=(0,ℓ0)=(z,ℓc)and(y,ℓa)=(x,ℓa)in(14),then (x,ℓa)=(0,ℓ0) ⊛ ((((0,ℓ0) ⊛ (x,ℓa)) ⊛ (0,ℓ0)) ⊛ (((0,ℓ0) ⊛ (0,ℓ0)) ⊛ (0,ℓ0))) =(0,ℓ0) ⊛ ((0,ℓ0) ⊛ (x,ℓa)) (17) by(16).Assumethat(0,ℓ0) ⊛ (x,ℓa)=(0,ℓ0) ⊛ (y,ℓb).Then (x,ℓa)=(0,ℓ0) ⊛ ((0,ℓ0) ⊛ (x,ℓa))=(0,ℓ0) ⊛ ((0,ℓ0) ⊛ (y,ℓb))=(y,ℓb)

14 Y.B.Jun

by(17)whichproves

(0,ℓ0) ⊛ (x,ℓa)=(0,ℓ0) ⊛ (y,ℓb) ⇒ (x,ℓa)=(y,ℓb). (18)

Putting(x,ℓa)=(0,ℓ0),(y,ℓb)=(0,ℓ0) ⊛ (y′,ℓb′ )and(z,ℓc)=(z′,ℓc′ )in(14)induces (0,ℓ0) ⊛ (y ′,ℓb′ )=(0,ℓ0) ⊛ ((((0,ℓ0) ⊛ ((0,ℓ0) ⊛ (y ′,ℓb′ )) ⊛ (z ′,ℓc′ ))⊛ (((0,ℓ0) ⊛ (0,ℓ0)) ⊛ (z ′,ℓc′ ))) =(0,ℓ0) ⊛ (((y ′,ℓb′ ) ⊛ (z ′,ℓc′ )) ⊛ ((0,ℓ0) ⊛ (z ′,ℓc′ )))

Itfollowsfrom(18)that (y ′,ℓb′ )=(((y ′,ℓb′ ) ⊛ (z ′,ℓc′ )) ⊛ ((0,ℓ0) ⊛ (z ′,ℓc′ ))) (19)

Ifwesubstitute(x,ℓa),(y,ℓb)and(z,ℓc)for(x′,ℓa′ ),(0,ℓ0) ⊛ ((z′,ℓc′ ) ⊛ (x′,ℓa′ ))and(0,ℓ0),respectively, in(14),then (0,ℓ0) ⊛ ((z ′,ℓc′ ) ⊛ (x ′,ℓa′ )) =(x ′,ℓa′ ) ⊛ ((((0,ℓ0) ⊛ ((0,ℓ0) ⊛ ((z ′,ℓc′ ) ⊛ (x ′,ℓa′ )))) ⊛ (0,ℓ0)) ⊛ (((0,ℓ0) ⊛ (x ′,ℓa′ )) ⊛ (0,ℓ0))) =(x ′,ℓa′ ) ⊛ (((z ′,ℓc′ ) ⊛ (x ′,ℓa′ )) ⊛ ((0,ℓ0) ⊛ (x ′,ℓa′ ))) =((x ′,ℓa′ ) ⊛ (z ′,ℓc′ ))

(20) In(14),taking(x,ℓa)=(y′,ℓb′ ) ⊛ (w,ℓd),(y,ℓb)=(y′,ℓb′ ) ⊛ (z′,ℓc′ )and(z,ℓc)=(0,ℓ0) ⊛ (y′,ℓb′ )imply that (y ′,ℓb′ ) ⊛ (z ′,ℓc′ )=((y ′,ℓb′ ) ⊛ (w,ℓd)) ⊛ [(((0,ℓ0) ⊛ ((y ′,ℓb′ ) ⊛ (z ′,ℓc′ ))) ⊛ ((0,ℓ0) ⊛ (y ′,ℓb′ ))) ⊛ (((0,ℓ0) ⊛ ((y ′,ℓb′ ) ⊛ (w,ℓd))) ⊛ ((0,ℓ0) ⊛ (y ′,ℓb′ )))] (21)

Using(19)and(20),weget ((0,ℓ0) ⊛ ((y ′,ℓb′ ) ⊛ (z ′,ℓc′ ))) ⊛ ((0,ℓ0) ⊛ (y ′,ℓb′ )) =((z ′,ℓc′ ) ⊛ (y ′,ℓb′ )) ⊛ ((0,ℓ0) ⊛ (y ′,ℓb′ ))=(z ′,ℓc′ ). (22) Similarly,wehave ((0,ℓ0) ⊛ ((y ′,ℓb′ ) ⊛ (w,ℓd))) ⊛ ((0,ℓ0) ⊛ (y ′,ℓb′ ))=(w,ℓd). (23)

Combining(21),(22)and(23)induces (y ′,ℓb′ ) ⊛ (z ′,ℓc′ )=((y ′,ℓb′ ) ⊛ (w,ℓd)) ⊛ ((z ′,ℓc′ ) ⊛ (w,ℓd)). Therefore ⟨(X,ℓX ), ⊛⟩ isaB-algebrawiththespecialelement(0,ℓ0)byTheorem 3.4. ThefollowingtheoremshowstheprocessofinducingapairedB-algebrausingagroup. Theorem3.6. If (X, ◦, 0) isagroup,thenthetwodimensional X-eventfulalgebra ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩ is apairedB-algebrawhere

⊛ :(X,ℓX ) × (X,ℓX ) → (X,ℓX ), ((x,ℓa), (y,ℓb)) → (x ◦ y 1,ℓa◦b 1 ) =(x ∗ y,ℓa∗b) Proof. Let(x,ℓa), (y,ℓb), (z,ℓc) ∈ (X,ℓX ).Then(x,ℓa) ⊛ (x,ℓa)= (x ◦ x 1,ℓa◦a 1 ) =(0,ℓ0)and(x,ℓa) ⊛ (0,ℓ0)= (x ◦ 0 1,ℓa◦0 1 ) =(x ◦ 0,ℓa◦0)=(x,ℓa).Also ((x,ℓa) ⊛ (y,ℓb)) ⊛ (z,ℓc)= (x ◦ y 1,ℓa◦b 1 ) ⊛ (z,ℓc) = ((x ◦ y 1) ◦ z 1,ℓ(a◦b 1)◦c 1 ) = (x ◦ (z ◦ y) 1,ℓa◦(c◦b) 1 )

Twodimensionaleventsetanditsapplicationinalgebraicstructures 15

and

(x,ℓa) ⊛ ((z,ℓc) ⊛ ((0,ℓ0) ⊛ (y,ℓb)))=(x,ℓa) ⊛ ((z,ℓc) ⊛ (0 ◦ y 1,ℓ0◦b 1 ))

=(x,ℓa) ⊛ ((z,ℓc) ⊛ (y 1,ℓb 1 )) =(x,ℓa) ⊛ (z ◦ (y 1) 1,ℓc◦(b 1) 1 )

=(x,ℓa) ⊛ (z ◦ y,ℓc◦b)= (x ◦ (z ◦ y) 1,ℓa◦(c◦b) 1 ) .

Hence((x,ℓa) ⊛ (y,ℓb)) ⊛ (z,ℓc)=(x,ℓa) ⊛ ((z,ℓc) ⊛ ((0,ℓ0) ⊛ (y,ℓb))).Therefore ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩ isa pairedB-algebra.

Let X :=(X, ∗, 0)beanalgebra.Inatwodimensional X-eventfulalgebra ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩,we considerthefollowingassertions.

(((x,ℓa) ⊛ (y,ℓb)) ⊛ ((x,ℓa) ⊛ (z,ℓc))) ⊛ ((z,ℓc) ⊛ (y,ℓb))=(0,ℓ0), (24) ((x,ℓa) ⊛ ((x,ℓa) ⊛ (y,ℓb))) ⊛ (y,ℓb)=(0,ℓ0), (25) (0,ℓ0) ⊛ (x,ℓa)=(0,ℓ0), (26) (x,ℓa) ⊛ (y,ℓb)=(0,ℓ0), (y,ℓb) ⊛ (x,ℓa)=(0,ℓ0) ⇒ (x,ℓa)=(y,ℓb) (27) forall x,y,z,a,b,c ∈ X

Definition3.7. Givenanalgebra X :=(X, ∗, 0),let ⟨(X,ℓX ), ⊛⟩ beatwodimensional X-eventfulalgebra withaspecialelement (0,ℓ0).Ifitsatisfies (11), (24) and (25),wesaythat ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩ isatwo dimensionalBCI-eventfulalgebra.IfatwodimensionalBCI-eventfulalgebra ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩ satisfies thecondition (26),itiscalledatwodimensionalBCK-eventfulalgebra.

Example3.8. (1)Consideranalgebra X :=(X, ∗, 0) where X = {0,a} andthebinaryoperation“∗”is givenbyTable 3.Givenaset Q = {α,β},defineamapping ℓ asfollows:

Table3: Cayleytableforthebinaryoperation“∗” ∗ 0 a 0 0 0 a a 0 ℓ : X → Q,x → { α if x =0, β if x = a.

Then (X,ℓX )= {(0,ℓ0), (0,ℓa), (a,ℓ0), (a,ℓa)} = {(0,α), (0,β), (a,α), (a,β)} andtheoperation ⊛ isgiven byTable 4.Itisroutinetoverifythat ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩ isatwodimensionalBCK-eventfulalgebra.

Table4: Cayleytableforthebinaryoperation“∗”

⊛ (0,ℓ0)(0,ℓa)(a,ℓ0)(a,ℓa) (0,ℓ0)(0,α)(0,α)(0,α)(0,α) (0,ℓa)(0,β)(0,α)(0,β)(0,α) (a,ℓ0)(a,α)(a,α)(0,α)(0,α) (a,ℓa)(a,β)(a,α)(0,β)(0,α)

(2)ThepairedB-algebra ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩ inExample 3.2 istwodimensionalBCI-eventfulalgebra. Ingeneral,twodimensionalBCK/BCI-eventfulalgebra ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩ doesnotsatisfythecondition (27)asseeninthefollowingexamples.

16 Y.B.Jun

Table5: Cayleytableforthebinaryoperation“∗”

∗ 0 a b c 0 0 0 c b a a 0 c b b b b 0 c c c c b 0

Example3.9. Consideranalgebra X =(X, ∗, 0) where X = {0,a,b,c} andthebinaryoperation“∗”is givenbyTable 5 Givenaset Q = {0 2, 0 5, 0 7},defineamapping ℓ asfollows: ℓ : X → Q,x → { 0 2if x ∈{0,a} 0 7if x ∈{b,c}

Thenthetwodimensional X-eventsetisgivenasfollows: (X,ℓX )= {(0, 0 2), (0, 0 7), (a, 0 2), (a, 0 7), (b, 0 2), (b, 0 7), (c, 0 2), (c, 0 7)}

anditisroutinetocheckthat ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩ isatwodimensionalBCI-eventfulalgebra.Butitisnot atwodimensionalBCK-eventfulalgebrasince (0,ℓ0) ⊛ (b,ℓc)=(c,ℓb) =(0,ℓ0).Notethat (0,ℓ0) ⊛ (0,ℓb)= (0,ℓc)=(0, 0 7) and (0,ℓb) ⊛ (0,ℓ0)=(0,ℓb)=(0, 0 7),but (0,ℓ0) =(0,ℓb).Hence ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩ does notsatisfythecondition (27)

Lemma3.10. If X :=(X, ∗, 0) isaBCK/BCI-algebra,then ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩ isatwodimensional BCK/BCI-eventfulalgebra.

Proof. Straightforward.

Bya pairedBCK/BCI-algebra wemeanatwodimensionalBCK/BCI-eventfulalgebra ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩ whichsatisfiesthecondition(27).

Example3.11. (1)ConsideraBCK-algebra X =(X, ∗, 0) where X = {0,a,b,c} andthebinaryoperation “∗”isgivenbyTable 6

Table6: Cayleytableforthebinaryoperation“∗” ∗ 0 a b c 0 0 0 0 0 a a 0 a a b b b 0 b c c c c 0

Givenanonemptyset Q,defineamapping ℓ asfollows: ℓ : X → Q,x → u.

Then (X,ℓX )= {(0,u), (a,u), (b,u), (c,u)},anditisclearthat ⟨(X,ℓX ), ⊛, (0,u)⟩ isatwodimensional BCK-eventfulalgebrabyLemma 3.10.Itisroutinetoverifythat ⟨(X,ℓX ), ⊛, (0,u)⟩ satisfiesthecondition (27).HenceitisapairedBCK-algebra. (2)Considerthealgebra X =(X, ∗, 0) inExample 3.9 andlet ℓ beamappingfrom X toanonempty set Q givenby ℓ(x)= v ∈ Q forall x ∈ X.Then (X,ℓX )= {(0,v), (a,v), (b,v), (c,v)},werecallthat X =(X, ∗, 0) isaBCI-algebra,andthus ⟨(X,ℓX ), ⊛, (0,v)⟩ isatwodimensionalBCI-eventfulalgebraby Lemma 3.10.Itisroutinetoverifythat ⟨(X,ℓX ), ⊛, (0,u)⟩ satisfiesthecondition (27).Henceitisapaired BCI-algebra.

Twodimensionaleventsetanditsapplicationinalgebraicstructures 17

WeconsiderageneralizationofExample 3.11.

Theorem3.12. Let X =(X, ∗, 0) beaBCK/BCI-algebra.Givenanonemptyset Q,let ℓ : X → Q bea constantmapping,say ℓ(x)= q forall x ∈ X.Then ⟨(X,ℓX ), ⊛, (0,q)⟩ isapairedBCK/BCI-algebra.

Proof. UsingLemma 3.10,weknowthat ⟨(X,ℓX ), ⊛, (0,q)⟩ isatwodimensionalBCK/BCI-eventfulalgebra. Let x,y,a,b ∈ X besuchthat(x,ℓa) ⊛ (y,ℓb)=(0,q)and(y,ℓb) ⊛ (x,ℓa)=(0,q).Then(0,q)=(x,ℓa) ⊛ (y,ℓb)=(x ∗ y,ℓa∗b)=(x ∗ y,q)and(0,q)=(y,ℓb) ⊛ (x,ℓa)=(y ∗ x,ℓb∗a)=(y ∗ x,q).Itfollowsthat x ∗ y =0and y ∗ x =0.Hence x = y,andso(x,ℓa)=(x,q)=(y,q)=(y,ℓb).Thisshowsthat ⟨(X,ℓX ), ⊛, (0,u)⟩ satisfiesthecondition(27).ThereforeitisapairedBCK/BCI-algebra.

Theorem 3.12 showsthatitcaninducemanyotherBCK/BCI-algebrasfromgivenaBCK/BCI-algebra. TheseinducedBCK/BCI-algebrasareisomorphiceachother.ThusaBCK/BCI-algebrainduceaunique pairedBCK/BCI-algebrauptoisomorphism.

Theorem3.13. Let X =(X, ∗, 0) beaBCK/BCI-algebra.Givenanonemptyset Q,ifamapping ℓ : X → Q isono-to-one,then ⟨(X,ℓX ), ⊛, (0,ℓ0))⟩ isapairedBCK/BCI-algebra.

Proof. UsingLemma 3.10,weknowthat ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩ isatwodimensionalBCK/BCI-eventful algebra.Let x,y,a,b ∈ X besuchthat(x,ℓa) ⊛ (y,ℓb)=(0,ℓ0)and(y,ℓb) ⊛ (x,ℓa)=(0,ℓ0).Then (0,ℓ0)=(x,ℓa) ⊛ (y,ℓb)=(x ∗ y,ℓa∗b)and(0,ℓ0)=(y,ℓb) ⊛ (x,ℓa)=(y ∗ x,ℓb∗a).Itfollowsthat x ∗ y =0, y ∗ x =0, ℓa∗b = ℓ0 and ℓb∗a = ℓ0.Since ℓ isone-to-one,wehave a ∗ b =0and b ∗ a =0.Itfollowsthat x = y and a = b.Hence(x,ℓa)=(y,ℓb).Thisshowsthat ⟨(X,ℓX ), ⊛, (0,ℓ0⟩ satisfiesthecondition(27). ThereforeitisapairedBCK/BCI-algebra.

Theorem3.14. Let X =(X, ∗, 0) beaBCK/BCI-algebra.Givenanonemptyset Q,ifamapping ℓ : X → Q satisfies ℓ 1(ℓ0)= {0},then ⟨(X,ℓX ), ⊛, (0,ℓ0))⟩ isapairedBCK/BCI-algebra.

Proof. UsingLemma 3.10,weknowthat ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩ isatwodimensionalBCK/BCI-eventful algebra.Let x,y,a,b ∈ X besuchthat(x,ℓa) ⊛ (y,ℓb)=(0,ℓ0)and(y,ℓb) ⊛ (x,ℓa)=(0,ℓ0).Then (0,ℓ0)=(x,ℓa) ⊛ (y,ℓb)=(x ∗ y,ℓa∗b)and(0,ℓ0)=(y,ℓb) ⊛ (x,ℓa)=(y ∗ x,ℓb∗a).Itfollowsthat x ∗ y =0, y ∗ x =0, ℓa∗b = ℓ0 and ℓb∗a = ℓ0.Hence a ∗ b ∈ ℓ 1(ℓ0)= {0} and b ∗ a ∈ ℓ 1(ℓ0)= {0} whichshowsthat a ∗ b =0and b ∗ a =0.Itfollowsthat x = y and a = b.Hence(x,ℓa)=(y,ℓb).Thisshowsthat ⟨(X,ℓX ), ⊛, (0,ℓ0⟩ satisfiesthecondition(27).ThereforeitisapairedBCK/BCI-algebra.

Lemma3.15 ([3]). GivenaBCI-algebra X =(X, ∗, 0),thefollowingareequivalent, (i) X is p-semisimple. (ii) x ∗ (0 ∗ y)= y ∗ (0 ∗ x) forall x,y ∈ X

Theorem3.16. ThetwodimensionalBCI-eventfulalgebra ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩ inducedbya p-semisimple BCI-algebra X =(X, ∗, 0) isacommutativegroupundertheoperation ⊙ whichisgivenby ⊙ :(X,ℓX ) × (X,ℓX ) → (X,ℓX ), ((x,ℓa), (y,ℓb)) → (x,ℓa) ⊛ ((0,ℓ0) ⊛ (y,ℓb))

Proof. ByLemma 3.10,weknowthat ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩ isatwodimensionalBCI-eventfulalgebra.Let (x,ℓa), (y,ℓb), (z,ℓc) ∈ (X,ℓX ).Then (x,ℓa) ⊙ (y,ℓb)=(x,ℓa) ⊛ ((0,ℓ0) ⊛ (y,ℓb))=(x,ℓa) ⊛ (0 ∗ y,ℓ0∗b) =(x ∗ (0 ∗ y),ℓa∗(0∗b))=(y ∗ (0 ∗ x),ℓb∗(0∗a)) =(y,ℓb) ⊛ (0 ∗ x,ℓ0∗a)=(y,ℓb) ⊛ ((0,ℓ0) ⊛ (x,ℓa)) =(y,ℓb) ⊙ (x,ℓa)

18 Y.B.Jun
(28)

byLemma 3.15,and ((y,ℓb) ⊙ (z,ℓc)) ⊙ (x,ℓa) =((y,ℓb) ⊛ ((0,ℓ0) ⊛ (z,ℓc))) ⊛ ((0,ℓ0) ⊛ (x,ℓa)) = ((y ∗ (0 ∗ z)) ∗ (0 ∗ x),ℓ(b∗(0∗c))∗(0∗a)) = ((y ∗ (0 ∗ x)) ∗ (0 ∗ z),ℓ(b∗(0∗a))∗(0∗c)) =((y,ℓb) ⊛ ((0,ℓ0) ⊛ (x,ℓa))) ⊛ ((0,ℓ0) ⊛ (z,ℓc)) =((y,ℓb) ⊙ (x,ℓa)) ⊙ (z,ℓc)

Using(28)and(29),weget

(x,ℓa) ⊙ ((y,ℓb) ⊙ (z,ℓc))=((y,ℓb) ⊙ (z,ℓc)) ⊙ (x,ℓa)=((y,ℓb) ⊙ (x,ℓa)) ⊙ (z,ℓc)=((x,ℓa) ⊙ (y,ℓb)) ⊙ (z,ℓc) Now, (0,ℓ0) ⊙ (x,ℓa)=(0,ℓ0) ⊛ ((0,ℓ0) ⊛ (x,ℓa)) =(0,ℓ0) ⊛ (0 ∗ x,ℓ0∗a) =(0 ∗ (0 ∗ x),ℓ0∗(0∗a))=(x,ℓa), whichshowsthat(0,ℓ0)istheidentityelementof(X,ℓX ).Finally,weshowthat(0,ℓ0) ⊛ (x,ℓa)isthe inverseofanyelement(x,ℓa).Infact, (x,ℓa) ⊙ ((0,ℓ0) ⊛ (x,ℓa))=(x,ℓa) ⊛ ((0,ℓ0) ⊛ ((0,ℓ0) ⊛ (x,ℓa))) = (x ∗ (0 ∗ (0 ∗ x)),ℓa∗(0∗(0∗a))) =(x ∗ x,ℓa∗a)=(0,ℓ0).

Therefore ⟨(X,ℓX ), ⊙, (0,ℓ0)⟩ isacommutativegroup.

Corollary3.17. Let X =(X, ∗, 0) beaBCI-algebrawhichsatisfiesanyoneofthefollowingassertions.

(∀x ∈ X)(0 ∗ x =0 ⇒ x =0), (30)

(∀a ∈ X)(X = {a ∗ x | x ∈ X}), (31) (∀a,x ∈ X)(a ∗ (a ∗ x)= x), (32)

(∀a,x,y,z ∈ X)((x ∗ y) ∗ (z ∗ a)=(x ∗ z) ∗ (y ∗ a)), (33)

(∀x,y ∈ X)(0 ∗ (y ∗ x)= x ∗ y), (34) (∀x,y,z ∈ X)((x ∗ y) ∗ (x ∗ z)= z ∗ y) (35)

ThenthetwodimensionalBCI-eventfulalgebra ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩ isacommutativegroupunderthe operation ⊙.

Theorem3.18. Let f : X → Y beanontohomomorphismofBCK/BCI-algebras.If ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩ satisfiesthecondition (27),then ⟨(Y,ζY ), ⊛, (0,ζ0)⟩ isapairedBCK/BCI-algebrawhere ζ isamapping from Y to Q. Proof. ByLemma 3.10,weknowthat ⟨(X,ℓX ), ⊛, (0,ℓ0)⟩ isatwodimensionalBCK/BCI-eventfulalgebra. Let(x′,ζa′ ), (y′,ζb′ ), (z′,ζc′ ) ∈ (Y,ζY ).Thenthereexist x,y,z,a,b,c ∈ X suchthat f (x)= x′,f (y)= y′ , f (z)= z′,f (a)= a′,f (b)= b′ and f (c)= c′.Hence

(((x ′,ζa′ ) ⊛ (y ′,ζb′ )) ⊛ ((x ′,ζa′ ) ⊛ (z ′,ζc′ ))) ⊛ ((z ′,ζc′ ) ⊛ (y ′,ζb′ ))

=(((f (x),ζf(a)) ⊛ (f (y),ζf(b))) ⊛ ((f (x),ζf(a)) ⊛ (f (z),ζf(c)))) ⊛ ((f (z),ζf(c)) ⊛ (f (y),ζf(b)))

=((f (x) ∗ f (y),ζf(a)∗f(b)) ⊛ (f (x) ∗ f (z),ζf(a)∗f(c))) ⊛ (f (z) ∗ f (y),ζf(c)∗f(b))

=((f (x ∗ y),ζf(a∗b)) ⊛ (f (x ∗ z),ζf(a∗c))) ⊛ (f (z ∗ y),ζf(c∗b))

=(f (x ∗ y) ∗ f (x ∗ z),ζf(a∗b)∗f(a∗c)) ⊛ (f (z ∗ y),ζf(c∗b))

=(f (((x ∗ y) ∗ (x ∗ z)) ∗ (z ∗ y)),ζf(((a∗b)∗(a∗c))∗(c∗b)))

=(f (0),ζf(0))=(0,ζ0),

Twodimensionaleventsetanditsapplicationinalgebraicstructures 19
(29)

(((x ′,ζa′ ) ⊛ ((x ′,ζa′ ) ⊛ (y ′,ζb′ ))) ⊛ (y ′,ζb′ )) =(((f (x),ζf(a)) ⊛ ((f (x),ζf(a)) ⊛ (f (y),ζf(b)))) ⊛ (f (y),ζf(b))) =((f (x),ζf(a)) ⊛ (f (x) ∗ f (y),ζf(a)∗f(b))) ⊛ (f (x),ζf(a)) =((f (x),ζf(a)) ⊛ (f (x ∗ y),ζf(a∗b))) ⊛ (f (x),ζf(a)) =(f (x ∗ (x ∗ y)),ζf(a∗(a∗b))) ⊛ (f (x),ζf(a)) =(f ((x ∗ (x ∗ y)) ∗ y),ζf((a∗(a∗b)))∗b) =(f (0),ζf(0))=(0,ζ0), and(x′,ζa′ ) ⊛ (x′,ζa′ )=(f (x),ζf(a)) ⊛ (f (x),ζf(a))=(f (x ∗ x),ζf(a∗a))=(f (0),ζf(0))=(0,ζ0).Hence ⟨(Y,ζY ), ⊛, (0,ζ0)⟩ isatwodimensionalBCI-eventfulalgebra.Since(0,ζ0) ⊛ (x′,ζa′ )=(f (0),ζf(0)) ⊛ (f (x),ζf(a))=(f (0 ∗ x),ζf(0∗a))=(f (0),ζf(0))=(0,ζ0),weknowthat ⟨(Y,ζY ), ⊛, (0,ζ0)⟩ isatwo dimensionalBCK-eventfulalgebra.Assumethat(x′,ζa′ ) ⊛ (y′,ζb′ )=(0,ζ0)and(y′,ζb′ ) ⊛ (x′,ζa′ )=(0,ζ0). Then (0,ζ0)=(x ′,ζa′ ) ⊛ (y ′,ζb′ )=(f (x),ζf(a)) ⊛ (f (y),ζf(b))=(f (x) ∗ f (y),ζf(a)∗f(b)) and (0,ζ0)=(y ′,ζb′ ) ⊛ (x ′,ζa′ )=(f (y),ζf(b)) ⊛ (f (x),ζf(a))=(f (y) ∗ f (x),ζf(b)∗f(a)), whichimplythat f (x) ∗ f (y)=0, f (y) ∗ f (x)=0, f (a) ∗ f (b)=0and f (b) ∗ f (a)=0.Hence x′ = f (x)= f (y)= y′ and a′ = f (a)= f (b)= b′.Therefore(x′,ζa′ )=(y′,ζb′ ).Consequently, ⟨(Y,ζY ), ⊛, (0,ζ0)⟩ isa pairedBCK/BCI-algebra.

4Conclusions

Wehaveintroducedtwo-dimensionaleventsetsandhaveappliedittoalgebraicstructures.WehaveintroducedthenotionsoftwodimensionalBCK/BCI-eventfulalgebra,pairedB-algebraandpairedBCK/BCIalgebra,andhaveinvestigatedseveralproperties.Wehaveconsideredconditionsfortwodimensional eventfulalgebratobeaB-algebraandaBCK/BCI-algebra.WehavediscussedtheprocessofinducingapairedB-algebrausingagroup,andhaveestablishedacommutativegroupusingtwodimensional BCI-eventfulalgebra.WehavepresentedexamplestoshowthatatwodimensionaleventfulBCK/BCIalgebraisnotaBCK/BCI-algebra,andthenwehaveconsideredconditionsforatwodimensionaleventful BCK/BCI-algebratobeaBCK/BCI-algebra.WehavestudiedapairedBCK/BCI-algebrainrelationto theBCK/BCI-homomorphism.

References

[1] A.A.A.Agboola,B.Davvaz,F.Smarandache, Neutrosophicquadruplealgebraichyperstructures, Annals ofFuzzyMathematicsandInformatics,14(1)(2017),29–42.

[2] S.A.Akinleye,F.Smarandache,A.A.A.Agboola, Onneutrosophicquadruplealgebraicstructures, NeutrosophicSetsandSystems,12(2016),122–126.

[3] Y.Huang, BCI-algebra, SciencePress,Beijing,2006.

[4] Y.B.Jun,S.Z.Song,S.J.Kim, Eventanditsapplicationinalgebraicstructures, NewMathematicsand NaturalComputation,(inpress).

[5] Y.B.Jun,S.Z.Song,F.Smarandache,H.Bordbar, NeutrosophicquadrupleBCK/BCI-algebras, Axioms,7(2018),41.

[6] J.Meng,Y.B.Jun, BCK-algebras, KyungmoonsaCo.Seoul,Korea,1994.

20 Y.B.Jun

[7] M.MohseniTakallo,Y.B.Jun, Commutativeneutrosophicquadrupleidealsofneutrosophicquadruple BCK-algebras, JournalofAlgebraicHyperstructuresandLogicalAlgebras,1(1)(2020),95–105.

[8] J.Neggers,H.S.Kim, OnB-algebras, MatematickiVesnik,54(1-2)(2002),21–29.

[9] F.Smarandache, Neutrosophy,neutrosophicprobability,set,andlogic, ProquestInformationandLearning,AnnArbor,Michigan,USA,105p.,1998.http://fs.gallup.unm.edu/eBook-neutrosophics6.pdf(last editiononline).

[10] F.Smarandache, Aunifyingfieldinlogics:Neutrosophiclogic.Neutrosophy,neutrosophicset,neutrosophicprobability, AmericanReserchPress,Rehoboth,NM,1999.

[11] F.Smarandache, Neutrosophicquadruplenumbers,refinedneutrosophicquadruplenumbers,absorbance law,andthemultiplicationofneutrosophicquadruplenumbers, NeutrosophicSetsandSystems,10 (2015),96–98.

Twodimensionaleventsetanditsapplicationinalgebraicstructures 21

Turn static files into dynamic content formats.

Create a flipbook
Issuu converts static files into: digital portfolios, online yearbooks, online catalogs, digital photo albums and more. Sign up and create your flipbook.