[GAP Forum] Order and Size

[Alexander Hulpke]

Dear Forum,

On Jan 29, 2014, at 1/29/14 8:27, Benjamin Sambale <benjamin.sambale at gmail.com> wrote:

> Dear GAP users,
> 
> I'm using GAP 4.7.2 and just ran into the following strange behavior:
> 
> G:=AbelianGroup([4,4,4]);;
> A:=AutomorphismGroup(G);;
> x:=First(A,a->Order(a)<>Size(Group(a)));
> [ f1*f2*f3, f5, f1*f2*f6 ] -> [ f1, f1*f2*f4*f5*f6, f2*f3*f6 ]

Thank you for the report.
This is a small oversight in the new method for element order for automorphisms. It only arises if an automorphism phi has a power phi^n that will be given on a longer generating set. (Automorphisms of abelian groups are the prime case of this I think.)

This will be corrected in the next release.

Regards,

  Alexander Hulpke