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BASIC ALGEBRAS

 
Acknowledgements
 
Introduction
 
Basic Algebras
      Creation
      Access Functions
      Elementary Operations
 
Modules over Basic Algebras
      Indecomposable Projective Modules
      Creation
      Access Functions
      Predicates
      Elementary Operations
 
Homomorphisms
      Creation
      Access Functions
      Projective Covers
 
Opposite Algebras
      Creation
      Injective Modules
 
Cohomology
 
Group Algebras of p-groups
      Access Functions
      Projective Resolutions
      Cohomology Generators
      Cohomology Rings
      Restrictions and Inflations
 
A-infinity Algebra Structures on Group Cohomology
      Homological Algebra Toolkit
 
Bibliography







DETAILS

 
Introduction

 
Basic Algebras

      Creation
            BasicAlgebra(Q) : SeqEnum[Tup] -> AlgBas
            BasicAlgebra(G, k) : GrpPerm, FldFin -> AlgBas
            BasicAlgebra(F,R,s,P): AlgFr, SeqEnum, RngIntElt, SeqEnum -> AlgBas
            BasicAlgebra(F,R) : AlgFr, SeqEnum -> AlgBas
            TensorProduct(A, B) : AlgBas, AlgBas-> AlgBas

      Access Functions
            NumberOfProjectives(B) : AlgBas -> RngIntElt
            B . i : AlgBas, RngIntElt -> AlgBasElt
            BaseRing(B) : AlgBas -> Rng
            VectorSpace(B) : AlgBas -> ModTupFld
            Dimension(B) : AlgBas -> RngIntElt
            Basis(B) : AlgBas -> SeqEnum
            Generators(B) : AlgBas -> SeqEnum
            IdempotentGenerators(B) : AlgBas -> SeqEnum
            IdempotentPositions(B) : AlgBas -> SeqEnum
            NonIdempotentGenerators(B) : AlgBas -> SeqEnum
            Random(B) : AlgBas -> AlgBasElt
            NumberOfGenerators(B) : AlgBas -> RngIntElt
            DimensionsOfProjectiveModules(B) : AlgBas -> SeqEnum
            DimensionsOfInjectiveModules(B) : AlgBas -> SeqEnum

      Elementary Operations
            a + b : AlgBasElt, AlgBasElt -> AlgBasElt
            a * b : AlgBasElt, AlgBasElt -> AlgBasElt
            a ^ n : AlgBasElt, RngIntElt -> AlgBasElt
            Example AlgBas_BasicAlgebras (H88E1)
            Example AlgBas_BasicAlgebras-2 (H88E2)
            Example AlgBas_BasicAlgebras-3 (H88E3)

 
Modules over Basic Algebras

      Indecomposable Projective Modules
            ProjectiveModule(B, i) : AlgBas, RngIntElt -> ModRng
            PathTree(B, i) : AlgBas, RngIntElt -> ModRng
            ActionGenerator(B, i) : AlgBas, RngIntElt -> SeqEnum
            IdempotentActionGenerators(B, i) : AlgBas, RngIntElt -> SeqEnum
            NonIdempotentActionGenerators(B, i) : AlgBas, RngIntElt -> SeqEnum
            Injection(B, i, v) : AlgBas, RngIntElt, ModRngElt -> AlgBasElt

      Creation
            AModule(B, Q) : AlgBas, SeqEnum[AlgMatElt] -> ModRng
            ProjectiveModule(B, S) : AlgBas, SeqEnum[RngIntElt] -> ModAlg, SeqEnum, SeqEnum
            IrreducibleModule(B, i) : AlgBas, RngIntElt -> ModAlg
            ZeroModule(B) : AlgBas -> ModAlg
            RightRegularModule(B) : AlgBas -> ModAlg
            RegularRepresentation(v) : AlgBasElt -> AlgMatElt
            JacobsonRadical(M) : ModAlg -> ModAlg
            Socle(M) : ModAlg -> ModAlg

      Access Functions
            Algebra(M) : ModAlg -> AlgBas
            Dimension(M) : ModAlg -> RngIntElt
            Action(M) : ModAlg -> AlgMat

      Predicates
            IsSemisimple(M) : ModAlg -> BoolElt, SeqEnum
            IsProjective(M) : ModAlg -> BoolElt, SeqEnum
            IsInjective(M) : ModAlg -> BoolElt, SeqEnum

      Elementary Operations
            m * b : ModAlgElt, AlgBasElt -> ModAlgElt
            Example AlgBas_AModules (H88E4)
            Example AlgBas_AModules-2 (H88E5)

 
Homomorphisms

      Creation
            AHom(M, N) : ModAlg, ModAlg -> ModMatFld
            PHom(M,N) : ModAlg, ModAlg -> ModMatFld
            ZeroMap(M, N) : ModAlg, ModAlg -> ModMatFld
            LiftHomomorphism(x, n) : ModAlgElt, RngIntElt -> ModMatFldElt
            LiftHomomorphism(X, N) : SeqEnum[ModAlgElt], SeqEnum[RngIntElt] -> ModMatFldElt
            Pushout(M, f1, N1, f2, N2) : ModAlg, ModMatFldElt, ModAlg, ModMatFldElt, ModAlg -> ModAlg, ModMatFldElt, ModMatFldElt
            Pullback(f1, M1, f2, M2, N) : ModAlg, ModMatFldElt, ModAlg, ModMatFldElt, ModAlg -> ModAlg, ModMatFldElt, ModMatFldElt

      Access Functions
            IsModuleHomomorphism(f) : ModMatFldElt -> BoolElt
            Domain(f) : ModMatFldElt -> ModAlg
            Codomain(f) : ModMatFldElt -> ModAlg
            Kernel(f) : ModMatFldElt -> ModAlg,ModMatFldElt
            Cokernel(f) : ModMatFldElt -> ModAlg,ModMatFldElt

      Projective Covers
            ProjectiveCover(M) : ModAlg -> ModAlg, ModMatFldElt, SeqEnum[ModMatFldElt], SeqEnum[ModMatFldElt], SeqEnum[RngIntElt]
            ProjectiveResolution(M, n) : ModAlg, RngIntElt -> ModCpx, ModMatFldElt
            CompactProjectiveResolution(M, n) : ModAlg, RngIntElt -> Rec
            SyzygyModule(M, n) : ModAlg, RngIntElt -> ModAlg
            SimpleHomologyDimensions(M) : ModAlg -> SeqEnum
            Example AlgBas_Homomorphisms (H88E6)
            Example AlgBas_Homomorphisms-2 (H88E7)

 
Opposite Algebras

      Creation
            OppositeAlgebra(B) : AlgBas -> AlgBas
            Dual(M) : ModAlg -> ModAlg
            BaseChangeMatrix(A) : AlgBas -> ModAlg

      Injective Modules
            InjectiveModule(B, i) : AlgBas, RngIntElt -> ModAlg
            InjectiveHull(M) : ModAlg -> ModAlg, ModMatFldElt, SeqEnum[ModMatFldElt], SeqEnum[ModMatFldElt], SeqEnum[RngIntElt]
            InjectiveResolution(M, n) : ModAlg, RngIntElt -> ModCpx, ModMatFldElt
            CompactInjectiveResolution(M, n) : ModAlg, RngIntElt -> Rec
            InjectiveSyzygyModule(M, n) : ModAlg, RngIntElt -> ModAlg
            SimpleCohomologyDimensions(M) : ModAlg -> SeqEnum
            Example AlgBas_Opposite (H88E8)

 
Cohomology
      CohomologyRingGenerators(P) : Rec -> Rec
      CohomologyRightModuleGenerators(P, Q, CQ) : Rec, Rec, Rec -> Rec
      CohomologyLeftModuleGenerators(P, CP, Q) : Tup, Tup, Tup -> Tup
      DegreesOfCohomologyGenerators(C) : Rec -> SeqEnum
      CohomologyGeneratorToChainMap(P,Q,C,n) : ModCpx, ModCpx, Rec, RngIntElt -> MapChn
      CohomologyGeneratorToChainMap(P, C, n) : ModCpx, Tup, RngIntElt -> MapChn
      Example AlgBas_Cohomology-2 (H88E9)

 
Group Algebras of p-groups

      Access Functions
            Group(A) :AlgBasGrpP -> Grp
            PCGroup(A) :AlgBasGrpP -> Grp
            PCMap(A) : AlgBasGrpP -> Map
            AModule(M) : ModGrp -> ModAlg
            GModule(M) : AlgBasGrpP -> ModGrp, ModGrp
            GModule(M) : ModAlgBas -> ModGrp

      Projective Resolutions
            ResolutionData(A) : AlgBasGrpP -> Rec
            CompactProjectiveResolutionPGroup(M, n) : ModAlgBas, RngIntElt -> Rec
            ProjectiveResolutionPGroup(PR) : Rec -> ModCpx
            ProjectiveResolution(M, n) : ModAlgBas, RngIntElt -> ModCpx, ModMatFldElt
            ProjectiveResolution(PR) : Rec -> ModCpx, ModMatFldElt

      Cohomology Generators
            AllCompactChainMaps(PR) : Rec -> Rec
            CohomologyElementToChainMap(P, d, n) : ModCpx ,RngIntElt, RngIntElt -> MapChn
            CohomologyElementToCompactChainMap(PR, d, n): Rec, RngIntElt, RngIntElt -> ModMatFldElt

      Cohomology Rings
            CohomologyRing(k, n) : ModAlgBas, RngIntElt -> Rec
            MinimalRelations(R) : Rec -> SeqEnum

      Restrictions and Inflations
            RestrictionData(A,B) : AlgBasGrpP, AlgBasGrpP -> ModMatFldElt, ModMatFldElt, SeqEnum
            RestrictResolution(PR, RD) : Rec, Rec -> ModCpx
            RestrictionChainMap(P1,P2) : Rec, Rec -> MapChn
            RestrictionOfGenerators(PR1, PR2, AC1, AC2, REL2) : Rec, Rec, Rec, Rec, Rec -> SeqEnum
            InflationMap(PR2, PR1, AC2, AC1, REL1, theta) : Rec, Rec, Rec, Rec, Rec -> SeqEnum
            Example AlgBas_CohomologyRing (H88E10)

 
A-infinity Algebra Structures on Group Cohomology
      AInfinityRecord(G,n) : Grp, RngIntElt -> Rec
      MasseyProduct(Aoo,terms) : Rec, SeqEnum[RngElt] -> RngElt
      HighMap(Aoo,terms) : Rec, SeqEnum[RngElt] -> MapChn
      Example AlgBas_A-infinity mod 2 (H88E11)
      Example AlgBas_A-infinity mod 3 (H88E12)

      Homological Algebra Toolkit
            ActionMatrix(A,x) : AlgBas, Mtrx -> ModMatFldElt
            CohomologyRingQuotient(CR) : Rec -> Rng,Map
            LiftToChainmap(P,f,d) : ModCpx, Mtrx, RngIntElt -> MapChn
            NullHomotopy(f) : MapChn -> MapChn
            IsNullHomotopy(f,H) : MapChn, MapChn -> BoolElt
            ChainmapToCohomology(f,CR) : MapChn, Rec -> RngElt
            CohomologyToChainmap(xi,CR,P) : RngElt, Rec, ModCpx -> MapChn

 
Bibliography

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