                       README file for the XMod package 
                       ================================ 

Introduction 
------------
This package allows for computation with crossed modules; cat1-groups; morphisms of these structures; derivations of crossed modules and the corresponding sections of cat1-groups.
Experimental functions for crossed squares are now included. 
In October 2015 a new section on isoclinism of crossed modules was added. 

Distribution
-------------
The ``XMod'' package is distributed with the accepted GAP packages, see: 
     http://www.gap-system.org/Packages/xmod.html
It may also be obtained from the GitHub repository at:
     http://gap-packages.github.io/xmod/ 

Copyright
---------
The XMod package is Copyright {\copyright} Chris Wensley et al, 1997--2016. 
XMod 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 \URL{http://www.gnu.org/licenses/gpl.html}

Installation
------------
1) unpack `xmod-<version_number>.tar.gz' in the `pkg' subdirectory of the GAP root directory.
2) From within GAP load the package with:
gap> LoadPackage("XMod");
true
3) The file manual.pdf is in the `doc' subdirectory.

Contact
-------
If you have a question relating to XMod, encounter any problems, or have a suggestion for extending the package in any way, please 
 - email: c.d.wensley@bangor.ac.uk 
 - or report an issue at: https://github.com/gap-packages/xmod/issues/new 
