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<!--  manual.xml          XMOD documentation              Chris Wensley  -->
<!--                                                        & Murat Alp  -->
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<!--  $Id: manual.xml,v 2.12 2008/11/24 gap Exp $                       -->
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<?xml version="1.0" encoding="ISO-8859-1"?>
  <!-- $Id: manual.xml,v 2.12  Exp $ -->

<!DOCTYPE Book SYSTEM "gapdoc.dtd"
[<!ENTITY XMod "<Package>XMod</Package>">] >

<Book Name="XMod"> 

<TitlePage>
  <Title>&XMod;</Title>
  <Subtitle>Crossed modules and cat1-groups in &GAP;</Subtitle>
  <Version>Version 2.12</Version>

  <Author> Murat Alp
    <Email>malp@dumlupinar.edu.tr</Email>
    <Address>
      Dumlupinar Universitesi,<Br/>  
      Fen-Edebiyat Fakultesi, Matematik Bolumu<Br/>
      Merkez Kampus, Kutahya, Turkey.
    </Address>
  </Author>    
  <Author> Chris Wensley
    <Email>c.d.wensley@bangor.ac.uk</Email>
    <Homepage>http://www.bangor.ac.uk/~mas023/</Homepage>
    <Address>
      School of Computer Science, Bangor University,<Br/>
      Dean Street, Bangor, Gwynedd, LL57 1UT, U.K.
    </Address>
  </Author>

  <Date>November 2008</Date>

<Abstract>
The XMod package provides functions for computation with 
<List> 
<Item>
finite crossed modules and cat1-groups, and morphisms of these structures;
</Item>
<Item>
finite pre-crossed modules, pre-cat1-groups, and their Peiffer quotients;
</Item>
<Item>
derivations of crossed modules and sections of cat1-groups; 
</Item>
<Item>
the actor crossed square of a crossed module; and 
</Item>
<Item>
crossed squares and their morphisms (experimental version).
</Item>
</List>
<P/>
&XMod; was originally implemented in 1997 using the &GAP;3 language.
when the first author was studying for a Ph.D. <Cite Key="A1"/> in Bangor.
<P/>
In April 2002 the first and third parts were converted to &GAP;4, 
the pre-structures were added, and version 2.001 was released. 
The final two parts, covering derivations, sections and actors, 
were included in the January 2004 release 2.002 for {\GAP}~4.4.
<P/>
The current version is 2.12, released on 24th November 2008. 
<P/>
Bug reports, suggestions and comments are, of course, welcome. 
Please contact the second author at     
<Email>c.d.wensley@bangor.ac.uk</Email>.
</Abstract>

<Copyright> 
&copyright; 1997-2008 Murat Alp and Chris Wensley 
</Copyright>

<Acknowledgements>
This <Package>xmod</Package> package is released under the 
GNU General Public License (GPL).
This file is part of <Package>xmod</Package>, though as documentation
it is released under the
GNU Free Documentation License
(see <URL>http://www.gnu.org/licenses/licenses.html#FDL</URL>).
<P/>
<Package>xmod</Package> 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.
<P/>
<Package>xmod</Package> is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  
See the GNU General Public License for more details.
<P/>
You should have received a copy of the GNU General Public License
along with <Package>xmod</Package>; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA. 
<P/>
For more details, see 
<URL>http://www.fsf.org/licenses/gpl.html</URL>. 
<P/>
This documentation was prepared with the <Package>GAPDoc</Package> 
package of Frank L\"ubeck and Max Neunh\"offer. 
<P/>
The first author wishes to acknowledge support from 
Dumlupinar University and the Turkish government. 
</Acknowledgements>
</TitlePage>

<TableOfContents/>

<Body>

<#Include SYSTEM "intro.xml">
<#Include SYSTEM "gp2obj.xml">
<#Include SYSTEM "gp2map.xml">
<#Include SYSTEM "gp2up.xml">
<#Include SYSTEM "gp2act.xml">
<#Include SYSTEM "gp2ind.xml">
<#Include SYSTEM "gp3obj.xml">
<#Include SYSTEM "util.xml">
<#Include SYSTEM "history.xml">

</Body>

<Bibliography Databases="manual"/>

<TheIndex/>

</Book>
