[GAP Forum] polycyclic representation

[Bill Allombert]

On Tue, Sep 18, 2018 at 02:00:14PM +0000, Joshua Edward Hunt wrote:
> Dear Bill & Forum,
> 
> I suspect the issue here is that GAP defines Comm to be a^-1*b^-1*a*b,
> not a*b*a^-1*b^-1. At least, if you use the definition for Comm that
> you gave in your Magma code, then GAP identifies H as (16,7). I would
> assume it's the same issue in your other example.

Ah thanks! Indeed it works correctly in all my tests after fixing this...
I would never have guessed...

Cheers,
Bill.