Dear Gap Forum,

Igor Schein wrote:

Thanks a lot, that's exactly what I needed. Now I can answer my original
question:

gap> IsomorphicSubgroups(SmallGroup(32,29),SmallGroup(8,4));
[ [ f1, f2 ] -> [ f1, f2 ], [ f1, f2 ] -> [ f1*f5, f1*f2 ] ]

So SmallGroup(32,29) indeed contains a quaterunion subgroup.

As the person who wrote this function, let me just add that
`IsomorphicSubgroups' tries to find possible images of a generating set. If
the group you want to embed has many generators (for example if it is
elementary abelian) this is likely to become slow and a method more along
thelines of Joachim Neub"users first suggestion will be better.

I don't understand this though:

\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
gap> IsomorphicSubgroups(SmallGroup(32,29),SmallGroup(4,1));
List Element: <list>[1] must have an assigned value at
return i[1];

Why error?

I was not able to reproduce the problem in 4r2fix8, but if I remember
correctly we had such a problem (with cyclic groups?) a while ago which
got corrected in a bugfix. Could you check whether you have up to fix 8
installed? (If yes, and the problem still arises, please esend us a mail at
gap-trouble@dcs.st-and.ac.uk and we will investigate.)

Best regards,

Alexander Hulpke

-- Colorado State University, Department of Mathematics,
Weber Building, Fort Collins, CO 80523, USA
email: hulpke@math.colostate.edu, Phone: ++1-970-4914288
http://www.math.colostate.edu/~hulpke

Miles-Receive-Header: reply