A GAP 4 package for
Computing with Radicals, Injectors
Schunck classes and Projectors
of finite soluble groups

Author:

Burkhard Höfling, e-mail: firstinitial.lastname@tu-bs.de replacing ö by oe

Language:

GAP (requires at least Version 4.5)

Operating System:

any

Current version:

1.4.6

Download:

crisp-1.4.6.tar.bz2 in .tar.bz2 format
Other formats available from the CRISP page on the main GAP server.

Home page:

http://www.icm.tu-bs.de/~bhoeflin/crisp/index.html

CRISP manual

Available in HTML format Adobe Acrobat PDF format

Development version

Accessible via GitHub repository

Bugs and suggestions

GitHub issue tracker or by e-mail to the author.

Description

The GAP package CRISP provides algorithms for computing subgroups of finite soluble groups related to group classes. In particular, it allows to compute 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 Xmust 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.