> < ^ Date: Wed, 04 Nov 1998 23:05:44 -0600
< ^ From: Russell Blyth <blythrd@SLU.EDU >
< ^ Subject: Re: Factorization

Dear Gap Forum experts:

I have another situation in which commands that worked in Gap 3 no longer
work in Gap 4. (Again, this comes from a project being used in a first
abstract algebra course).

This works:

gap> G:=DirectProduct(DihedralGroup(8),DihedralGroup(8));
<pc group with 6 generators>
gap> C:=Centre(G);
Group([ f3, f6 ])
gap> F:=FactorGroup(G,C);
<pc group with 4 generators>

This doesn't:

gap> G:=DirectProduct(AlternatingGroup(4),DihedralGroup(4));
<group with 4 generators>
gap> C:=Centre(G);
<group with 3 generators>
gap> F:=FactorGroup(G,C);
Error no method found for operation GroupByGenerators with 2 arguments
<function>( <arguments> ) called from read-eval-loop
Entering break read-eval-print loop, you can 'quit;' to quit to outer loop,
or you can return to continue

How do I work around this?

Thanks for any help you can provide.

Russell Blyth

Russell D. Blyth                                 blythrd@slu.edu
Associate Professor                              http://sylow.slu.edu
Department of Mathematics and Computer Science   Voice: (314)977-2458
Saint Louis University                           Department: (314)977-2444
221 N. Grand Blvd.                               Fax: (314)977-3649
St. Louis, MO 63103                              Dept: http://euler.slu.edu
USA                                              Univ: http://www.slu.edu

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