Dear GAP Forum,

Neil Zanella asked

Is anyone aware of any packages avaliable for GAP that deal
specifically with group rings and their units?

For dealing with group rings, there is a package written
by Philip Osterlund.
It is available from the usual GAP servers,
and can be found there as `pub/gap/deposit/gap/groupring'.

As for units of group rings,
the GAP share package SISYPHOS written by Martin Wursthorn
provides an algorithm to compute the normalized units
of the group algebras of p-groups over the field with
p elements.
More general, one can compute unit groups of quotients
of these group algebras by powers of the augmentation ideal.

SISYPHOS is a C program with an interface to GAP,
whereas the group ring programs by Philip Osterlund
are written in GAP.

Thomas