Module homomorphism records have at least the following components.
isGeneralMapping :true,
isMapping :true,
isHomomorphism:true,
domain :Mappings,
source :
range :
preImage :
basisImage :
preimagesBasis :basisImage
operations :If the source is a (factor of a) free module then there are also the components
genimages :
alghom :If the source is a (factor of a) row module then there are also the components
basisSource :
imagesBasis :basisSource.
GAP 3.4.4