  
  [1X1 [33X[0;0YIntroduction[133X[101X
  
  [33X[0;0YGroupoids  are  mathematical  categories in which every arrow is invertible.
  The  [5Xgroupoids[105X package provides functions for the computation with groupoids
  and  their  morphisms;  for  graphs  of  groups and graphs of groupoids. The
  package is far from complete, and development continues.[133X
  
  [33X[0;0YIt  was  used  by Emma Moore in her thesis [Moo01] to calculate normal forms
  for [13Xfree products with amalgamation[113X, and for [13XHNN-extensions[113X when the initial
  groups have rewriting systems.[133X
  
  [33X[0;0YThe    package    may    be    obtained    as    a   compressed   tar   file
  [11Xgroupoids-version.number.tar.gz[111X by ftp from one of the following sites:[133X
  
  [30X    [33X[0;6Ythe                [5Xgroupoids[105X                GitHub               site:
        [7Xhttps://github.com/gap-packages.github.io/groupoids/[107X.[133X
  
  [30X    [33X[0;6Yany                  [5XGAP[105X                 archive,                 e.g.
        [7Xhttps://www.gap-system.org/Packages/packages.html[107X;[133X
  
  [33X[0;0YThe      package      also      has      a     GitHub     repository     at:
  [7Xhttps://github.com/gap-packages/groupoids/[107X.[133X
  
  [33X[0;0YThe information parameter [10XInfoGroupoids[110X takes default value [10X1[110X which, for the
  benefit of new users, causes more messages to be printed out when operations
  fail. When raised to a higher value, additional information is printed out.[133X
  
  [33X[0;0YHelp is available in the usual way.[133X
  
  [4X[32X  Example  [32X[104X
    [4X[28X[128X[104X
    [4X[25Xgap>[125X [27XLoadPackage( "groupoids" );[127X[104X
    [4X[28X[128X[104X
  [4X[32X[104X
  
  [33X[0;0YFor  version  1.05  the  package  was completely restructured, starting with
  [13Xmagmas  with  objects[113X  and  their mappings, and building up to groupoids via
  semigroups  with  objects  and  monoids  with objects. From version 1.07 the
  package includes some functions to implement constructions for automorphisms
  and homotopies, as described in [AW10]. More functions will be released when
  time permits.[133X
  
  [33X[0;0YOnce  the  package  is  loaded, it is possible to check the installation has
  proceeded  correctly  by  running  the  test  suite  of the package with the
  command [10X ReadPackage("groupoids","tst/testing.g"); [110X. Additional tests may be
  run    using   [10X   ReadPackage("groupoids","tst/testextra.g");.[110X   (The   file
  [10X"tst/testall.g"[110X is used for automated testing.)[133X
  
  [33X[0;0YYou may reference this package by mentioning [BMPW02], [Moo01] and [AW10].[133X
  
  [33X[0;0YAdditional  information  on  [13XComputational Higher Dimensional Algebra[113X can be
  found      in      the      notes      on      crossed      modules      at:
  [7Xhttps://github.com/cdwensley/xmod-notes[107X.[133X
  
