                             The XMOD package

This is the README file for the GAP package ``XMOD''.

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.

Version 1 of ``XMOD'' became available for GAP3R4P4.
THis is the first version released for GAP4.

The ``XMOD'' package is bundled in with the accepted  GAP  packages
.zoo archive: `acceptedpkg<XXX>.zoo',  for  some  GAP  version  number
<XXX>. When this archive is unpacked in the `pkg' subdirectory via:

  unzoo -x acceptedpkg<XXX>

a directory `xmod',  along  with  the  directories  for  the  other
accepted packages in the archive, will have been created.

It  may  also  be  unpacked  individually  from  the   .zoo   archive:
`example-<XXX>.zoo', for some package version <XXX>. At  the  time  of
writing the ``XMOD'' package version was 2.001.

Chris Wensley and Murat Alp  -  April 2002.