> < ^ Date: Mon, 01 Mar 1993 11:57:14 +0100
> < ^ From: Martin Schoenert <martin.schoenert@math.rwth-aachen.de >
< ^ Subject: Re: [problems with symmetric groups]

In his e-mail message of 1993/02/26, Bruce Kaskel writes:
Could someone possibly tell me what I am doing wrong here?

gap> s4 := SymmmetricGroup( 4 );;
gap> cc := ConjugacyClassesSubgroups( s4 );;
gap> cc2 := cc[2];;
gap> r := Representative( cc2 );;
gap> g := Group( r );
Group( (3,4) )
gap> 2syl := SylowSubgroup( g, 2 );
Error, Record: element 'orbit' must have an assigned value at
...

This is a bug in GAP 3.1 (patchlevel 0). It is fixed in the first
upgrade to V3R1P1 and in GAP 3.2. The problem was that
'PermGroupOps.SylowSubgroup' assumed that once the size of a permutation
group is known (and it is known for 'g', since it was known for 'r'),
also a stabilizer chain is known (but 'g' has no stabilizer chain,
because this is not copied by 'Group').

Martin.

-- .- .-. - .. -.  .-.. --- ...- . ...  .- -. -. .. -.- .-
Martin Sch"onert,   Martin.Schoenert@Math.RWTH-Aachen.DE,  +49 241 804551
Lehrstuhl D f"ur Mathematik, Templergraben 64, RWTH, D 51 Aachen, Germany

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