[GAP Forum] Re: Semigroups question (fwd)

[James Mitchell]

---------- Forwarded message ----------
Date: Fri, 11 Mar 2005 00:32:58 +0000 (GMT)
From: James Mitchell <jamesm at mcs.st-andrews.ac.uk>
To: mjoao at classic.univ-ab.pt
Subject: Re: Semigroups question
Dear Joao,

[...] 
The answer is: yes you could calculate this automorphism 
group, but as far as I know there is no clever way of doing it. You would 
simply have to make all the mappings from the direct product to itself and 
then check which are automorphisms and which are not. If the direct 
product has even a very small size, then this could be an unfeasibly large 
calculation. 

Does this answer your question?

Best,

James

> >Date: Fri, 25 Feb 2005 14:35:54 +0000 (WET)
> >From: Joao Araujo <mjoao at classic.univ-ab.pt>
> >To: forum at gap-system.org
> >Subject: [GAP Forum] Direct product of semigroups
> >
> >
> >I would like to compute the automorphism group of a direct product of
> >(two) semigroups. Is it possible to do that with GAP?
> >
> >I thank in advance any help.
> >
> >Joao
>