> < ^ Date: Fri, 16 Nov 2001 09:36:54 +0100 (MEZ)
> < ^ From: Mathias Kratzer <kratzer@exp-math.uni-essen.de >
< ^ Subject: Re: presentation of a large group.. [part 2]

Dear Forum,

On Fri, 16 Nov 2001, MICHAEL HARTLEY wrote:

--> One person asked why I wanted the presentation when I already
--> had an permutation representation. The reason is that the group is
--> the group of a regular polytope, and the permutation representation
--> gives little intuitive understanding of the structure of the polytope.
--> The presentation will give that understanding.

Will it really? I'm far away from being a specialist on algorithms for
finding a set of defining relations in a given group but user
experience (and also the two examples in the GAP4-manual (section
45.1: "Creating Presentations")) make me feel pretty certain that
automatically generated presentations and "nice presentations" -- in
the sense that one can understand the group structure by looking at
the relations -- are very often two different sorts of things.

Best regards,
M. Kratzer

Dipl.-Math. Mathias Kratzer           | I_nstitute for 
E-Mail: kratzer@exp-math.uni-essen.de | E_xperimental  
Phone : +49-201-183-7680              | M_athematics     Ellernstr. 29     
Visit : IEM, Room 205                 |                  D-45326 ESSEN

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