Identities among relations

Version 2.43
Released 2019-05-29

This project is maintained by Christopher D. Wensley

Build Status Code Coverage

The GAP 4 package ‘IdRel’


The IdRel package is designed for computing the identities among relations of a group presentation using rewriting, logged rewriting, monoid polynomials, module polynomials and Y-sequences.


Version 1.001 of IdRel formed part of Anne Heyworth’s PhD thesis in December 1999. Version 2.02 was prepared for the GAP 4.4 release in March 2006 and deposited in the incoming directory on the St Andrews ftp server. A more detailed history will be included as Chapter 6 of the manual. IdRel became an accepted package in May 2015.


The IdRel package is distributed with the accepted GAP packages. It may also be obtained from the GitHub repository at:

The IdRel package is Copyright {\copyright} Chris Wensley and Anne Heyworth, 1999–2017.

IdRel is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

For details, see



If you have a question relating to IdRel, encounter any problems, or have a suggestion for extending the package in any way, please