[GAP Forum] Intersection of groups

[Katie Morrison]

Hi all, I was wondering if there was a command to find the intersection of
two groups that was more efficient than just the standard Intersection
command.  I'm currently trying to intersect two matrix groups, one which has
size on the order of 10^13 and the other which has size on the order of
10^22.  I let GAP run overnight and it still had not found the intersection
of these two groups when I used the Intersection command.  I'm very
surprised though because I had performed literally the same calculation in
Magma on an earlier occasion using the command meet and the calculation
finished in under a second in Magma.  I created the groups in precisely the
same way in Magma as I did in GAP, so I'm really not sure why the
calculation ran so quickly in Magma, but seems to have failed in GAP.  If
anyone has any advice on this topic, I'd really appreciate it.  Thanks for
the help.

Katie