[GAP Forum] Matrix group

[Petra Holmes]

Nicola,

On Fri, 13 Aug 2004, Nicola SOTTOCORNOLA wrote:

> This group has a normal subgroup H of size 16.
> 
> H:=MaximalNormalSubgroups(G);                                                       
> [ <group of 5x5 matrices of size 16 in characteristic 0> ]
> 
The output from this looks like a list of length 1, where the element H[1]
group.

> I'd like to study the structure of H. Why I obtain the following error msg?
> 
> gap> P := PresentationViaCosetTable(H);;
> Error, first argument must be a group called from
> <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
> brk> 
> 
You have given it a list, not a group.  Try
P:=PresentationViaCosetTable(H[1]);

Beth