[GAP Forum] weird bug with wreath products

[Alexander Hulpke]

Dear GAP- Forum,

On Jan 12, 2006, at 11:24 , Laurent Bartholdi wrote:

>
> it seems to me that there's a problem with wreath products:
>
> GAP4, Version: 4.4.5 of 13-May-05, i686-pc-linux-gnu-gcc
> gap> G := WreathProduct(CyclicGroup(3),Group((1,2,3),(4,5,6)));
> <group of size 6561 with 3 generators>
> gap> Gc := Image(IsomorphismPcGroup(G));
> Group([ f1, f2, f3, f4, f5 ])
> gap> Size(Gc);
> 243

Thank you for reporting this bug. The problem arises if the group H  
in G\wr H is not acting transitively. In this case GAP might miss  
some generators for the base of the product.

This will be corrected in the next bugfix, please write me privately  
if you want a workaround now.

Best wishes and many thanks!

     Alexander Hulpke

-- Colorado State University, Department of Mathematics,
Weber Building, 1874 Campus Delivery, Fort Collins, CO 80523-1874, USA
email: hulpke at math.colostate.edu, Phone: ++1-970-4914288
http://www.math.colostate.edu/~hulpke