[GAP Forum] determining the groups isomorphic to another group

[Burkhard Höfling]

Dear Levie,

> Let
> M:=[Group([ (4,5), (2,3), (1,2)(4,5) ]), Group([ (4,5), (2,3),  
> (1,3) ]),
> Group([ (4,5), (2,5), (1,3) ]), Group([ (4,5), (2,5), (1,3)(4,5) ]),
> Group([ (4,5), (2,5), (1,3)(2,4) ]),Group([ (4,5), (2,5), (1,3) 
> (2,5) ]),
> Group((1,3,4,5),(1,6)(2,5))];
> Suppose I want to know which of the elements of G are isomorphic to  
> another group, say,
> g:=Group((1,2,3,4,5,6),(1,6)(2,5)(3,4));
> I tried doing this but indirectly:
> isom:=Filtered(M, x -> ForAll(x, z -> IsomorphismGroups(x,g)=fail));

Why don't you use

isom:=Filtered(M, x -> ForAll(x, z -> IsomorphismGroups(x,g) <> fail));

Or maybe I have misunderstood your question?

Cheers,

Burkhard.