The following sections describe the np-quotient functions. PQuotient
allows to compute quotient of prime power order of finitely presented
groups. For further references see HN80 and Vau84.
There is a C standalone version of the p-quotient algorithm, the ANU p-Quotient Program, which can be called from GAP. For further information see chapter ANU Pq.
GAP 3.4.4