# Semigroups

Version 3.0.5

This project is maintained by J. D. Mitchell

## Getting Semigroups

To get the latest version of the package download the archive file semigroups-x.x.x.tar.gz from the Semigroups webpage, and inside the pkg subdirectory of your GAP installation unpack semigroups-x.x.x.tar.gz, by, for example, doing:

gunzip semigroups-x.x.x.tar.gz; tar xvf semigroups-x.x.x.tar


This will create a subdirectory semigroups-x.x.x.

## Issues

For questions, remarks, suggestions, and issues please use the issue tracker.

## Installation

It is assumed that you have a working copy of GAP with version number 4.9.0 or higher. The most up-to-date version of GAP and instructions on how to install it can be obtained from the main GAP page.

The following is a summary of the steps that should lead to a successful installation of Semigroups:

• get the IO package version 4.4.4 or higher

• get the Orb package version 4.7.5 or higher. Both Orb and Semigroups perform better if Orb is compiled, so compile Orb!

• ensure that the Digraphs package version 0.7.1 or higher is available. Digraphs must be compiled before Semigroups can be loaded.

• get the genss package version 1.5 or higher

• download the package archive semigroups-x.x.x.tar.gz from the Semigroups webpage.

• unzip and untar the file semigroups-x.x.x.tar.gz, for example, using

  gunzip semigroups-x.x.x.tar.gz; tar xvf semigroups-x.x.x.tar


this should create a directory called semigroups-x.x.x.

• locate the pkg directory of your GAP directory, which contains the directories lib, doc and so on. Move the directory semigroups-x.x.x into the pkg directory.

• from version 3.0.0, it is necessary to compile the Semigroups package. To do this, inside the pkg/semigroups-x.x.x directory, type
• ./configure
• make

Further information about this step can be found in manual section entitled “Compiling the kernel module”

• start GAP in the usual way.

• type LoadPackage("semigroups");

Enjoy!