[GAP Forum] Finding free presentation of a group

Alexander Hulpke hulpke at math.colostate.edu
Thu Oct 17 22:59:22 BST 2013


Dear Forum,

On Oct 12, 2013, at 10/12/13 3:44, Takjk Taj <mathpn59 at yahoo.com> wrote:

> Dear Gap forum,
> 
> For a finite group G, let G\cong F/R for a free group F. If N is a normal subgroup of G. How we can find the normal subgroup S of F by GAP such that N\cong S/R?

If phi is a homomorphism from F to G   (likely constructed as
GroupHomomorphismByImages on the generators), take
PreImage(Phi,N)

Regards,

   Alexander Hulpke





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