GAP package CRISP
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                       The CRISP package
                         Version CRISP_VERSION

The GAP package CRISP provides algorithms for computing subgroups of
finite soluble groups related to a group class C. In particular, it
allows to compute C-radicals and C-injectors for Fitting classes (and
Fitting sets) C, C-residuals for formations C, and C-projectors for
Schunck classes C. In order to carry out these computations, the group
class C must be represented by an algorithm which can decide 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.

This version of CRISP requires at least GAP 4.5.

In order to install CRISP, you have to get the current package archive file 


or any other package format suitable for your system.

You can download the current package archive from the packages section of

To install CRISP, move the downloaded package archive file into the 
`pkg' directory in which you plan to install CRISP. Usually, this will be 
the directory 'pkg' in the GAP directory.

Then decompress the package archive. You should now have a directory
'crisp-CRISP_VERSION' in the 'pkg' directory. That's all. By default,
CRISP is automatically loaded when you start GAP, and should be listed
among the loaded packages.

If you already have a previous version of CRISP, you can delete that

To load the CRISP package manually, type

    LoadPackage ("crisp");

at the GAP prompt. If everything is ok, this should return `true'.

The development version of CRISP is available via GitHub, at

Please do not hesitate to report any bugs or other problems/suggestions
via the GitHub issue tracker at">
or by e-mail to the author.

Burkhard Höfling