CRISP (Computing with Radicals, Injectors, Schunck classes and
Projectors) provides algorithms for computing subgroups of finite
soluble groups related to group classes. In particular, it allows
computing F-radicals and F-injectors for Fitting classes (and Fitting
sets) F, F-residuals for formations F, and X-projectors for Schunck
classes X. In order to carry out these computations, the group classes
F and X must be given by an algorithm which decides membership in the
group class.
Moreover, CRISP contains algorithms for the computation of normal
subgroups invariant under a prescribed set of automorphisms and
belonging to a given group class. This includes an improved method to
compute the set of all normal subgroups of a finite soluble group, its
characteristic subgroups, and the socle and p-socles for given primes p.
