Chris Wensley

It seems that this is an issue I could have a go at: fairly tedious, but not particularly tricky. The following steps appear to be required: (1) Convert PreImagesRepresentative to...

Just as we have an error in the example above: gap> PreImagesRepresentative( f, x ); (1,2)(3,4) so a similar error occurs with PreImages: gap> PreImages(f,x); RightCoset(Group(()),(1,2)(3,4))

Sorry, but I do not understand this at all: (a) I can see no problematic link in the Utils manual; (b) my development version is not at the moment in...

PR #5073 attempts to address this issue, and has been sitting awaiting a review for some weeks while so much else has been happening (GAPDays, 4.12.1, etc.). But who would...

Earlier in this issue @hulpke suggested that the same concerns might apply to ImagesRepresentative (and Images, ImagesElm, ImagesSet). If it was thought worthwhile, I'd be willing to start a new...

There were 3 files where it appeared that after a call to PreImagesRepresentativeNC a test for the return of fail followed immediately: alghom.gi, ghomperm.gi, mapphomo.gi.

I am very perplexed by some methods in mapprep.gi which are full of tests for "im = fail". Should these be methods for the non-NC PreImagesRepresentative?

@fingolfin Sorry if I'm slow on the uptake, but I do not understand what will be broken. As it stands at present PreImagesRepresentative just calls PreImagesRepresentativeNC (without any test). So,...

PreImages produces the same error as PreImagesRepresentative, so the same procedure applies.

Further details of the use by packages of one or more of PreImages, PreImagesElm, PreImagesSet and PreImagesRepresentative. In the following list 'I' indicates that an InstallMethod for one of these...