
gap/pcpgrp:

higher level functions for pcp groups:

grpint.gi     -- intersection with normal subgroup
grpinva.gi    -- invariant subspaces
torsion.gi    -- finite subgroups (TorsionSubgroup / FiniteSubgroups)
maxsub.gi     -- maximal subgroups
findex.gi     -- subgroups of finite index  (LowIndex)
nindex.gi     -- normal subgroups of finite index
nilpot.gi     -- centralizers in nilpotent groups
