diff --git a/doc/algebra.xml b/doc/algebra.xml index 60293b0..a9349e2 100644 --- a/doc/algebra.xml +++ b/doc/algebra.xml @@ -2,7 +2,7 @@ - + @@ -19,7 +19,8 @@ All the algebras considered in this package will be associative and commutative. Scalars belong to a commutative ring k with 1 \neq 0.

-Why not a field? A group ring over the integers is not an algebra. +(Why not a field? +A group ring over the integers is not an algebra. [CDW])

diff --git a/lib/algebra.gd b/lib/algebra.gd index e5fef56..0b7ee31 100644 --- a/lib/algebra.gd +++ b/lib/algebra.gd @@ -28,13 +28,6 @@ DeclareOperation( "InclusionMappingAlgebra", [ IsAlgebra, IsAlgebra ] ); DeclareOperation( "RestrictionMappingAlgebra", [ IsAlgebraHomomorphism, IsAlgebra, IsAlgebra ] ); -## remove this "not IsBound(...)" hack as soon as the declarations -## have been moved to the main GAP library -if not IsBound( AlgebraHomomorphismByFunction ) then - DeclareOperation( "AlgebraHomomorphismByFunction", - [ IsAlgebra, IsAlgebra, IsFunction ] ); -fi; - DeclareOperation( "ModuleHomomorphism", [ IsAlgebra, IsRing ] ); @@ -47,8 +40,6 @@ DeclareOperation( "AllIdempotentAlgebraHomomorphisms", ############################## algebra actions #################### -DeclareGlobalFunction( "ElementsLeftActing" ); - DeclareProperty( "IsAlgebraAction", IsMapping ); DeclareGlobalFunction( "AlgebraAction" ); diff --git a/lib/algebra.gi b/lib/algebra.gi index e61f2b0..574035c 100644 --- a/lib/algebra.gi +++ b/lib/algebra.gi @@ -517,28 +517,6 @@ end ); ############################## algebra actions ############################ -############################################################################# -## -#F ElementsLeftActing( ) -## -InstallGlobalFunction( ElementsLeftActing, -function (ac) - local AB,B,list,uzAB,uzA,uzB,k,i,elB; - AB := Source(ac); - B := Range(ac); - elB := Elements(B); - list := []; - uzAB := Length(AB); - uzB := Length(elB); - uzA := uzAB/uzB; - k := 1; - for i in [1..uzA] do - Add(list,AB[k][1]); - k := k+uzB; - od; - return Set(list); -end ); - ############################################################################# ## #F IsAlgebraAction( ) @@ -569,7 +547,7 @@ end ); ############################################################################# ## -#F AlgebraAction( , ) crossed module from given boundary & action +#F AlgebraAction( ) crossed module from given boundary & action ## InstallGlobalFunction( AlgebraAction, function( arg ) @@ -593,7 +571,7 @@ function( arg ) return AlgebraActionByModule( arg[1],arg[2] ); fi; # alternatives not allowed - Error( "usage: AlgebraAcrion( A, I, B ); or various options" ); + Error( "usage: AlgebraAction( A, I, B ); or various options" ); end ); #############################################################################