Systems related to Group Theory

Sisyphos

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#      SISYPHOS - Computing in modular group algebras of p-groups     #
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#                           Martin Wursthorn                          #
#                Mathematisches Institut B, 3.Lehrstuhl               #
#                        Universitaet Stuttgart                       #
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Introduction

SISYPHOS is a program package developed to compute with p-groups and their modular group algebras. It originated in an implementation of an algorithm by Roggenkamp, Scott and the author to test such group algebras for isomorphisms. This algorithm has been modified and improved to be applicable to p-groups as well. The following features are incorporated in the current implementation:

features dealing with modular group algebras of p-groups:: Symbolic computations with elements,; computation of centre, centralizers, lie ideals,; computing with subspaces and ideals,; isomorphism tests for such group algebras,; computation of a polycyclic presentation of the normalized units group,
features dealing with p-groups:: (outer) automorphisms of polycyclically presented p-groups,; isomorphisms between two polycyclically presented groups or a; freely presented and a polycyclically presented group,; tests for isomorphisms between two polycyclically presented groups; or a freely presented and a polycyclically presented group,; several output formats are supported (generators, element lists, polycyclic presentations for normalized automorphism groups)

The package can be used either as a GAP shared library via a special interface that allows the program to be called from within GAP by special GAP functions (see GAP documentation) or as a standalone program with its own user interface. The first possibility only allows access to the routines dealing with p-groups, but has the advantage that the results can be processed by GAP without any conversions. The second possibility gives access to all features of SISYPHOS, but though it is still possible to have some of the routines produce output in a GAP compatible format, you will have to reformat the output in general to resue it in some other computer algebra package.

Like GAP, the standalone version of SISYPHOS is an interactive system controlled by a command language. this command language, called 'Lapidar' is rather simple and does not yet support any structures that alter the flow of control, like branching instructions and loops. This language is described in the SISYPHOS manual.

The following instructions refer to the standalone version only. If you want to install SISYPHOS as GAP shared library, follow the instructions in the GAP manual.

Implementation

SISYPHOS is written in ANSI-C and should run on every UNIX system (and some non-UNIX systems) that provides an ANSI-C compiler (e.g. GNU cc). Compilers keeping to the old C standard will not be able to compile the sources.

Getting the sources

The sources for SISYPHOS, several group libraries and additional programs are available via anonymous ftp from http://web.mathematik.uni-stuttgart.de/sisyphos/

Contact address

In any case of difficulties whether with the installation or the usage of SISYPHOS, especially if you encounter any bugs send an email to the following address pluto@machnix.mathematik.uni-stuttgart.de.

It is very helpful if you include a copy of the input that produced the bug and the (erroneous) output of SISYPHOS. Moreover any form of constructive criticism is welcome. The program in its current state is by no means finished but is developped further permanently.

Martin Wursthorn
Mathematisches Institut B
3. Lehrstuhl
Universitaet Stuttgart
70550 Stuttgart
Tel.: +49 (0)711 685 5517
Fax.: +49 (0)711 685 5322

Sisyphos has been encorporated into GAP.

Special Purpose Systems