  
  [1m[4m[31m1. Introduction[0m
  
  This  manual  describes  the  [1mIdRel[0m  (version  2.02)  [1mGAP[0m  share package for
  computing  the  identities  among  relations  of  a group presentation using
  rewriting,  logged  rewriting,  monoid  polynomials,  module polynomials and
  Y-sequences.
  
  The  theoretical background for these computations is contained in Brown and
  Huebschumann [BH82], Brown and Razak Salleh [BR99] and is surveyed in [H99].
  
  [1mIdRel[0m  is  primarily  designed  for  the  computation  of  a  minimal set of
  generators  for  the  module of identities among relations. It also contains
  functions  which compute logged rewrite systems for group presentations (and
  complete  them  where possible), functions for operations involving elements
  of  monoid rings and functions for operations with elements of right modules
  over  monoid  rings.  The  Y-sequences  are  used  as  a  [22m[36mrewriting[0m  way  of
  representing  elements  of  a free crossed module (products of conjugates of
  group  relators  and  inverse  relators). The package is written entirely in
  [1mGAP[0m4, and requires no compilation.
  
  The  package  is  loaded  into [1mGAP[0m with the [22m[32mLoadPackage[0m command, and on-line
  help is available in the usual way.
  
  [22m[35m---------------------------  Example  ----------------------------[0m
    [22m[35m[0m
    [22m[35mgap> LoadPackage( "idrel" ); [0m
    [22m[35mgap> ?idrel[0m
    [22m[35m[0m
  [22m[35m------------------------------------------------------------------[0m
  
  The usual dvi, pdf and PostScript versions of the [1mIdRel[0m manual are available
  (as  [1mmanual.dvi[0m, [1mmanual.pdf[0m and [1mmanual.ps[0m respectively) in the [1mdoc[0m directory
  of  the  home  directory  of  [1mIdRel[0m. The information parameter [22m[32mInfoIdRel[0m has
  default  value  [22m[32m0[0m.  When raised to a higher value, additional information is
  printed  out.  [1mIdRel[0m  was originally developed in 1999 using [1mGAP[0m3, partially
  supported  by  a  University  of  Wales Research Assistantship for the first
  author,  Anne Heyworth. If you use [1mIdRel[0m to solve a problem then please send
  a  short  email  to  the second author, to whom bug reports, suggestions and
  other  comments  should  also  be  sent.  You  may  reference the package by
  mentioning [HW03] and [H99].
  
