  
  [1X1 Introduction to the [5XAtlasRep[1X Package[0X
  
  The  aim  of the [5XGAP[0m 4 package [5XAtlasRep[0m is to provide a link between [5XGAP[0m and
  the   "[5XATLAS[0m   of   Group   Representations",   a  database  that  comprises
  representations  of  many  almost  simple groups and information about their
  maximal subgroups. This database has been available independent of [5XGAP[0m at
  
  [7Xhttp://brauer.maths.qmul.ac.uk/Atlas[0m
  
  The  [5XAtlasRep[0m  package consists of this database (see Section [14X1.1[0m) and a [5XGAP[0m
  interface  (see  Section [14X1.2[0m); the latter is extended by further information
  available via the internet (see Section [14X1.3[0m).
  
  Information about installing and customizing the package can be found in the
  sections [14X1.4[0m, [14X1.5[0m, and [14X1.6[0m, [14X1.7[0m, [14X1.8[0m.
  
  Finally,  Section [14X1.9[0m  lists  the  changes  w.r.t. previous  releases of the
  package,  and  Section [14X1.10[0m acknowledges contributions of non-authors to the
  package.
  
  
  [1X1.1 An [5XATLAS[1X of Group Representations[0X
  
  The  [5XATLAS[0m of Group Representations consists of matrices over various rings,
  permutations,  and  shell scripts encoding so-called black box programs (see
  [Nic06]  and  Section [14X4.2[0m). Many of these scripts are straight line programs
  (see [BSWW01],   [SWW00],   and [14X'Reference:  Straight  Line  Programs'[0m)  and
  straight  line  decisions  (see  Section [14X4.1[0m). These programs can be used to
  compute  certain  elements  in  a  group  G  from  its  standard  generators
  (see [Wil96]  and [14X'Reference:  Standard  Generators of Groups'[0m), for example
  generators of maximal subgroups of G or representatives of conjugacy classes
  of G.
  
  The [5XATLAS[0m of Group Representations has been prepared by Robert Wilson, Peter
  Walsh, Jonathan Tripp, Ibrahim Suleiman, Richard Parker, Simon Norton, Simon
  Nickerson,   Steve   Linton,  John  Bray,  and  Rachel  Abbott  (in  reverse
  alphabetical order).
  
  The  information  was  computed  and composed using computer algebra systems
  such  as  [5XMeatAxe[0m  (see [Rin98]),  Magma  (see [CP96]),  and [5XGAP[0m (in reverse
  alphabetical  order).  Part of the constructions have been documented in the
  literature  on  almost  simple groups, or the results have been used in such
  publications, see for example the references in [CCNPW85] and [BN95].
  
  If you use the [5XATLAS[0m of Group Representations to solve a problem then please
  send  a  short  email to [7Xmailto:R.A.Wilson@qmul.ac.uk[0m about it. The [5XATLAS[0m of
  Group  Representations  database should be referenced with the entry [ATLAS]
  in the bibliography of this manual.
  
  If  your  work  made use of functions of the [5XGAP[0m interface (see Section [14X1.2[0m)
  then you should also reference this interface, as follows.
  
  [4X---------------------------  Example  ----------------------------[0X
    [4X@misc{ AtlasRep1.4,[0X
    [4X  author =       {Wilson, R. A. and Parker, R. A. and Nickerson, S. and[0X
    [4X                  Bray, J. N. and Breuer, T.},[0X
    [4X  title =        {{AtlasRep}, A \textsf{GAP} Interface to the Atlas of[0X
    [4X                  Group Representations,[0X
    [4X                  {V}ersion 1.4},[0X
    [4X  month =        {June},[0X
    [4X  year =         {2008},[0X
    [4X  note =         {Refereed \textsf{GAP} package},[0X
    [4X  howpublished = {http://www.math.rwth-aachen.de/\~{}Thomas.Breuer/atlasrep}[0X
    [4X}[0X
  [4X------------------------------------------------------------------[0X
  
  For  referencing  the  [5XGAP[0m  system  in  general,  use the entry [GAP] in the
  bibliography of this manual, see also
  
  [7Xhttp://www.gap-system.org[0m.
  
  
  [1X1.2 The GAP Interface to the [5XATLAS[1X of Group Representations[0X
  
  The  [5XGAP[0m  interface  to  the  [5XATLAS[0m  of  Group  Representations  consists of
  essentially two parts.
  
  First,  there is the [13Xuser interface[0m which allows the user to get an overview
  of  the contents of the database, and to access the data in [5XGAP[0m format; this
  is  described  in  Chapter [14X2[0m.  Advanced  users may add their own data to the
  database, this is described in Chapter [14X3[0m.
  
  Second,  there  is  [13Xadministrational  information[0m,  which  covers  also  the
  declaration  of  [5XGAP[0m  objects  such as straight line decisions and black box
  programs.  This  is  important  mainly  for  users  interested in the actual
  implementation  (e. g.,  for  modifying the package) or in using it together
  with the [10XC[0m-[5XMeatAxe[0m standalone (see [Rin98]); this is described in Chapter [14X5[0m.
  
  Information  concerning  the [10XC[0m-[5XMeatAxe[0m, including the manual [Rin98], can be
  found at
  
  [7Xhttp://www.math.rwth-aachen.de/LDFM/homes/MTX[0m
  
  The  [5XGAP[0m  interface  should  be  regarded  as preliminary. Hopefully it will
  become  more  user-friendly  when the [5XATLAS[0m of Group Representations will be
  integrated  into  a larger [5XGAP[0m database of groups and their representations,
  character tables, and tables of marks.
  
  The  interface  and  this manual have been provided by Thomas Breuer, except
  for  the  interpreter for black box programs (see Section [14X4.2[0m), which is due
  to  Simon  Nickerson.  Comments,  bug  reports,  and hints for improving the
  interface can be sent to [7Xmailto:sam@math.rwth-aachen.de[0m.
  
  
  [1X1.3 Web Services for the [5XAtlasRep[1X Package[0X
  
  The home page of the [5XAtlasRep[0m package is
  
  [7Xhttp://www.math.rwth-aachen.de/~Thomas.Breuer/atlasrep[0m
  
  Besides package archives and introductory package information, it provides
  
  --    the  current  file with the [13Xtable of contents[0m (the file [11Xgap/atlasprm.g[0m
        of the package), cf. [2XReloadAtlasTableOfContents[0m ([14X1.6-1[0m),
  
  --    a [13Xstarter archive[0m containing many small representations and programs,
  
  --    the    list    of   [13Xchanges   of   server   files[0m   in   HTML   format
        (cf. [2XAtlasOfGroupRepresentationsTestTableOfContentsRemoteUpdates[0m
        ([14X1.6-4[0m)), and
  
  --    an  [13Xoverview  of the data[0m available via the [5XGAP[0m interface to the [5XATLAS[0m
        of  Group  Representations,  in  HTML  format;  this is similar to the
        information shown by [2XDisplayAtlasInfo[0m ([14X2.5-1[0m); further information can
        be  found  on the home page of the [5XATLAS[0m (see the introduction to this
        chapter).
  
  
  [1X1.4 Installing the [5XAtlasRep[1X Package[0X
  
  To  install  the  package, unpack the archive file in a directory in the [11Xpkg[0m
  directory  of  your  local copy of [5XGAP[0m 4. This might be the [11Xpkg[0m directory of
  the  [5XGAP[0m 4  root  directory,  see [14X'Reference:  Installing a GAP Package'[0m for
  details.  It is however also possible to keep an additional [11Xpkg[0m directory in
  your  private  directories, see Section [14X'Reference: GAP Root Directory'[0m. The
  latter possibility [13Xmust[0m be chosen if you do not have write access to the [5XGAP[0m
  root directory.
  
  Data files (in the subdirectories [11Xdatagens[0m and [11Xdataword[0m of the package) that
  are  available from an earlier version of the package are in principle kept;
  see [2XAtlasOfGroupRepresentationsTestTableOfContentsRemoteUpdates[0m  ([14X1.6-4[0m) for
  necessary updates.
  
  If  it  is  likely that one will work offline, it makes sense to install the
  "starter archive" that can be downloaded from the package's homepage.
  
  The  package  consists entirely of [5XGAP[0m code, no external binaries need to be
  compiled  for  the package itself. However, if the [5XGAP[0m package [5XIO[0m [Neu07] is
  used  to  access  remote  data  files  (see Section [14X1.7-3[0m) then its external
  binary must be available.
  
  After  unpacking  the  package  archive,  it  should  be checked whether the
  subdirectories  [11Xdatagens[0m  and  [11Xdataword[0m  of the package directory have write
  permissions  for  those  users who will download files from the servers. The
  recommended permissions under UNIX are set as follows.
  
  [4X---------------------------  Example  ----------------------------[0X
    [4Xyou@unix> chmod 1777 atlasrep/data*[0X
    [4Xyou@unix> ls -ld atlasrep/data*[0X
    [4Xdrwxrwxrwt   3 you      you          1024 Oct 31 12:34 datagens[0X
    [4Xdrwxrwxrwt   3 you      you          1024 Oct 31 12:34 dataword[0X
  [4X------------------------------------------------------------------[0X
  
  For checking the installation of the package, you should start [5XGAP[0m, load the
  package (see Section [14X1.5[0m), and then call
  
  [4X---------------------------  Example  ----------------------------[0X
    [4Xgap> ReadPackage( "atlasrep", "tst/testinst.g" );[0X
  [4X------------------------------------------------------------------[0X
  
  If  the  installation  is  o.k. then the [5XGAP[0m prompt appears without anything
  else  being  printed;  otherwise  the  output  lines tell you what should be
  changed.
  
  More  test  files  are  available  in  the [11Xtst[0m directory of the package, see
  Section  [14X5.8[0m for details.
  
  [11XPDF[0m  and  HTML  versions  of  the  package  manual  are available in the [11Xdoc[0m
  directory of the package.
  
  
  [1X1.5 Loading the [5XAtlasRep[1X Package[0X
  
  The  [5XAtlasRep[0m  package  may be loaded automatically when [5XGAP[0m is started, for
  example  when  other  [5XGAP[0m packages require it, or it has to be loaded within
  the [5XGAP[0m session as follows.
  
  [4X---------------------------  Example  ----------------------------[0X
    [4Xgap> LoadPackage( "atlasrep" );[0X
    [4Xtrue[0X
  [4X------------------------------------------------------------------[0X
  
  See [14X'Reference: Loading a GAP Package'[0m for details about these alternatives.
  
  
  [1X1.6 Maintaining the Local Data of the [5XAtlasRep[1X Package[0X
  
  The  current  [13Xtable  of  contents[0m  of  the database is contained in the file
  [11Xgap/atlasprm.g[0m  of  the  [5XAtlasRep[0m package. This file is read by default when
  the  package is loaded. It may happen that new data files have been added to
  the  servers  since  the  last  release  of the [5XAtlasRep[0m package, thus it is
  useful to update the table of contents of the package from time to time.
  
  For  that,  one can fetch the most recent version of the file [11Xgap/atlasprm.g[0m
  from   the   home   page   of  the  package  (see  Section [14X1.3[0m),  either  by
  calling [2XReloadAtlasTableOfContents[0m ([14X1.6-1[0m) in a [5XGAP[0m session or "by hand". In
  the  latter  case,  the  new  file can then be read into the [5XGAP[0m session via
  [2XReplaceAtlasTableOfContents[0m  ([14X1.6-3[0m).  Alternatively,  one can add a line to
  the user's [11X.gaprc[0m file (see [14X'Reference: The .gaprc file'[0m), which assigns the
  filename of the current [11Xgap/atlasprm.g[0m file (as an absolute path or relative
  to  the  user's home directory, cf. [2XDirectory[0m ([14XReference: Directory[0m)) to the
  global variable [10XATLASREP_TOCFILE[0m; in this case, this file is read instead of
  the one from the package distribution when the package is loaded.
  
  Users  who  have write access to the directory where the [5XAtlasRep[0m package is
  installed  can  alternatively use the [11Xmaketoc[0m script in the [11Xetc[0m directory of
  the  package  for  regularly updating the file [11Xgap/atlasprm.g[0m. Users without
  this  write  access can store the new file in a different place, and read it
  with [2XReplaceAtlasTableOfContents[0m ([14X1.6-3[0m).
  
  [1X1.6-1 ReloadAtlasTableOfContents[0m
  
  [2X> ReloadAtlasTableOfContents( [0X[3Xdirname[0X[2X ) ____________________________[0Xfunction
  [6XReturns:[0X  [9Xfail[0m  if  the  required  table  of contents could not be reloaded,
            otherwise [9Xtrue[0m.
  
  Let [3Xdirname[0m be a string, which must be one of [10X"remote"[0m, [10X"local"[0m, or the name
  of a private data directory (see Chapter [14X3[0m).
  
  In  the  case of [10X"remote"[0m, the file [10Xatlasprm.g[0m is fetched from the package's
  home page, and then read into [5XGAP[0m. In the case of [10X"local"[0m, the subset of the
  data  listed  in  the  [10X"remote"[0m  table  of  contents  is considered that are
  actually  available  in the local data directories. In the case of a private
  directory,  its contents is inspected, and the table of contents for [3Xdirname[0m
  is  replaced  by the one obtained from inspecting the actual contents of the
  data directories (see Section [14X5.7[0m).
  
  [1X1.6-2 StoreAtlasTableOfContents[0m
  
  [2X> StoreAtlasTableOfContents( [0X[3Xfilename[0X[2X ) ____________________________[0Xfunction
  
  Let  [3Xfilename[0m be a string. This function prints the loaded table of contents
  of the servers to the file with name [3Xfilename[0m.
  
  [1X1.6-3 ReplaceAtlasTableOfContents[0m
  
  [2X> ReplaceAtlasTableOfContents( [0X[3Xfilename[0X[2X ) __________________________[0Xfunction
  
  Let   [3Xfilename[0m   be   the  name  of  a  file  that  has  been  created  with
  [2XStoreAtlasTableOfContents[0m ([14X1.6-2[0m).
  
  [2XReplaceAtlasTableOfContents[0m  first  removes  the  information  that  [5XGAP[0m has
  stored  about  the table of contents of the servers, and then reads the file
  with  name  [3Xfilename[0m,  thus replacing the previous information by the stored
  one.
  
  [1X1.6-4 AtlasOfGroupRepresentationsTestTableOfContentsRemoteUpdates[0m
  
  [2X> AtlasOfGroupRepresentationsTestTableOfContentsRemoteUpdates( [0X[3X[0X[2X ) __[0Xfunction
  [6XReturns:[0X  the  list of names of all locally available data files that should
            be removed.
  
  This  function  fetches  the file [11Xchanges.html[0m from the package's home page,
  extracts  the  times of changes for the data files in question, and compares
  them  with  the times of the last changes of the local data files. For that,
  the  [5XGAP[0m  package [5XIO[0m [Neu07] is needed; if it is not available then an error
  message is printed, and [9Xfail[0m is returned.
  
  If  the time of the last modification of a server file is later than that of
  the  local  copy  then  the  local  file  must  be updated. (This means that
  [10Xtouch[0ming files in the local directories will cheat this function.)
  
  It  is  useful  that  a  system  administrator  (i. e.,  someone who has the
  permission  to  remove  files  from the data directories) runs this function
  from  time  to  time,  and  afterwards removes the files in the list that is
  returned.   This   way,   new  versions  of  these  files  will  be  fetched
  automatically from the servers when a user asks for their data.
  
  
  [1X1.7 User Parameters for the [5XAtlasRep[1X Package[0X
  
  This section lists global parameters for which it might make sense to change
  their  defaults  by  assignments  to  global  variables, either just for the
  current  [5XGAP[0m  session  or  as  user  preferences  in  the user's [11X.gaprc[0m file
  (see [14X'Reference: The .gaprc file'[0m).
  
  
  [1X1.7-1 Local or Remote Access[0X
  
  There are two possibilities to use the [5XAtlasRep[0m package.
  
  [8X[13XLocal access only (offline)[0m[8X[0m
        You can restrict he access to the data that are actually stored in the
        local installation of [5XGAP[0m.
  
  [8X[13XRemote access (online)[0m[8X[0m
        If your computer is connected to a network that provides access to the
        [5XATLAS[0m  data  (for  example  the  internet)  then  the functions of the
        package may fetch the requested data automatically from remote servers
        when  they  are  required  for  the first time; these data are then by
        default  stored  in  the  local copy, so later access to them needs no
        network transfer.
  
  The  latter  possibility  is presently not used by other [5XGAP[0m packages, so it
  may  be  regarded as an important feature of the [5XAtlasRep[0m package. Anyhow it
  requires a few words of explanation.
  
  The  possibility  of  online access reflects in particular the fact that the
  [5XATLAS[0m  of  Group  Representations  is  designed  as  an [13Xopen database[0m, it is
  expected  to  grow.  As  soon  as  the  developers  of  the  [5XATLAS[0m  of Group
  Representations  add  new  information  to  the  servers,  these data become
  available  in  [5XGAP[0m  when remote access is enabled, after one has updated the
  corresponding table of contents (see Section [14X1.6[0m).
  
  Remote access is enabled if and only if the value of the [10Xremote[0m component of
  the  global variable [2XAtlasOfGroupRepresentationsInfo[0m ([14X5.1-5[0m) is [9Xtrue[0m. If one
  wants  to  work offline, i.e., if one does [13Xnot[0m want [5XGAP[0m to attempt accessing
  remote data then this value must be set to [9Xfalse[0m.
  
  Conversely,  if  the  default  value  of  the  [10Xremote[0m  component in your [5XGAP[0m
  installation  is  [9Xfalse[0m  then  changing  this  value  to  [9Xtrue[0m  may  be  not
  successful.  First,  it  might  be the case that no server is reachable. And
  second,  if  one can in principle [13Xdownload[0m files from a server then it might
  be  impossible  to actually [13Xstore[0m these files in the data directories of the
  installed  package;  in  this  case,  it  is  advisable to install the whole
  package or just its data directories in a private directory, see [14X'Reference:
  GAP Root Directory'[0m for details.
  
  
  [1X1.7-2 Adding and Removing Servers[0X
  
  When access to remote data is enabled (see Section [14X1.7-1[0m) then the available
  servers   are  given  by  the  [10Xservers[0m  component  of  the  global  variable
  [2XAtlasOfGroupRepresentationsInfo[0m ([14X5.1-5[0m).
  
  [13XRemoving[0m entries from this list means to disable access to the corresponding
  servers, [13Xadding[0m entries makes the corresponding servers available. Of course
  the  latter makes sense only if the new servers really exist, for example in
  a local network.
  
  Currently  there  is just one remote server. As soon as other servers become
  available,  or  a  server name is changed which makes it necessary to adjust
  the  [10Xservers[0m  component,  this  will  be  announced  in  the  [5XGAP[0m Forum, cf.
  [14X'Tutorial:  Further  Information about GAP'[0m. The same holds when upgrades of
  the package become available.
  
  
  [1X1.7-3 Accessing Data Files with the [5XGAP[1X Package [5XIO[1X or with [11Xwget[1X[0X
  
  When  access  to  remote  data is enabled (see Section [14X1.7-1[0m) then one needs
  either the [5XGAP[0m package [5XIO[0m [Neu07] or the external program [11Xwget[0m for accessing
  data files.
  
  The  chosen  alternative  is given by the value of the [10Xwget[0m component of the
  global variable [2XAtlasOfGroupRepresentationsInfo[0m ([14X5.1-5[0m).
  
  If  this  component has the value [9Xtrue[0m then only [11Xwget[0m is tried, if the value
  is [9Xfalse[0m then only the [5XIO[0m package is used. If this component is not bound or
  bound  to  another  value than [9Xtrue[0m or [9Xfalse[0m (this is also the default) then
  the  [5XIO[0m  package  is  preferred  to  [11Xwget[0m  if this package is available, and
  otherwise [11Xwget[0m is tried.
  
  Note  that  the  system  program  [11Xwget[0m may be not available, and that it may
  require  some  work  to  install it; hints for that can be found on the home
  page of the [5XAtlasRep[0m package (see Section [14X1.3[0m).
  
  
  [1X1.7-4 Compressed or Uncompressed Data Files[0X
  
  When  used with UNIX, [5XGAP[0m can read [11Xgzip[0mped files, see [14X'Reference: Saving and
  Loading     a     Workspace'[0m.     If     the     component    [10Xcompress[0m    of
  [2XAtlasOfGroupRepresentationsInfo[0m ([14X5.1-5[0m) has the value [9Xtrue[0m then each [5XMeatAxe[0m
  format  file  that  is fetched from a remote server is afterwards compressed
  with  [11Xgzip[0m.  This  saves  a  lot  of  space if many [5XMeatAxe[0m format files are
  accessed.  (Note  that  data  files  in  other  formats are very small.) For
  example,  at  the  time  of the release of version 1.4 there were about 8400
  data  files  in  [5XMeatAxe[0m  format, which needed about 1400 MB in uncompressed
  text  format  and  about 275 MB in compressed text format. The default value
  for the component [10Xcompress[0m is [9Xfalse[0m.
  
  
  [1X1.7-5 Customizing [10XDisplayAtlasInfo[1X[0X
  
  The  way  how  [2XDisplayAtlasInfo[0m  ([14X2.5-1[0m)  shows  the  requested  overview is
  controlled       by       the       component       [10XdisplayFunction[0m       of
  [2XAtlasOfGroupRepresentationsInfo[0m   ([14X5.1-5[0m).   The   default  value  is  [2XPrint[0m
  ([14XReference: Print[0m), another useful value is [2XPager[0m ([14XReference: Pager[0m).
  
  
  [1X1.7-6 Customizing the Access to Data Files[0X
  
  By  default,  local data files are stored in the subdirectories [11Xdatagens[0m and
  [11Xdataword[0m  of  the package, and the files are exactly the text files provided
  on the servers. However, a more flexible approach may be useful.
  
  First,  one  may want to use [13Xdifferent file formats[0m, for example the [5XMeatAxe[0m
  binary  files  that are provided by the servers parallel to the [5XMeatAxe[0m text
  files.  Second,  one  may  want  to use [13Xa different directory structure[0m, for
  example  the  same  structure  as  used on the servers –this makes sense for
  example  if  a  local  mirror of a server is available, because then one can
  read the server files directly, without transferring/copying them to another
  directory.
  
  As  a  consequence, one would like to customize the meaning of the following
  three access steps.
  
  [8XAre the required filed locally available?[0m
        The  required files may have a different name or a different path, and
        the data can be available in one file or can be distributed to several
        files.
  
  [8XHow can a file be made locally available?[0m
        A  different  server file may be fetched or some postprocessing may be
        required.
  
  [8XHow is the data of a file accessed by [5XGAP[0m[8X?[0m
        A different function may be needed to read the file.
  
  Details how to achieve this can be found in Section [14X5.2[0m.
  
  
  [1X1.7-7 Reading Large Matrices over Finite Fields[0X
  
  Matrices over finite fields in [5XGAP[0m can be represented in a compressed format
  that  needs  less  space  than  the  corresponding text file. Such a [5XMeatAxe[0m
  format  text file can be read by [2XScanMeatAxeFile[0m ([14X5.3-1[0m) either line by line
  (which  is  the  default) or as a whole; the latter is faster but needs more
  space  than  the  former.  For example, a 4370 by 4370 matrix over the field
  with  two  elements (as occurs for an irreducible representation of the Baby
  Monster)  requires less than 3 MB space in [5XGAP[0m but the corresponding [5XMeatAxe[0m
  format  text  file is more than 19 MB large, which means that when one reads
  the  file with the fast variant, [5XGAP[0m will temporarily grow by more than this
  value.   One   can   change   the   mode  by  setting  the  global  variable
  [2XCMeatAxe.FastRead[0m ([14X5.1-4[0m) to [9Xtrue[0m or [9Xfalse[0m, respectively.
  
  Note  that this parameter is meaningful only when [2XScanMeatAxeFile[0m ([14X5.3-1[0m) is
  used.  It  has  no  effect  for  example  if  [5XMeatAxe[0m binary files are read,
  cf. [2XFFMatOrPermCMtxBinary[0m ([14X5.3-5[0m).
  
  [1X1.7-8 AtlasOfGroupRepresentationsShowUserParameters[0m
  
  [2X> AtlasOfGroupRepresentationsShowUserParameters( [0X[3X[0X[2X ) ________________[0Xfunction
  
  This  function  prints  an  overview  of  the  current  values  of  the user
  parameters introduced in this section.
  
  
  [1X1.8 Extending the [5XATLAS[1X Database[0X
  
  Users  who  have  computed new representations that might be interesting for
  inclusion  into  the  [5XATLAS[0m  of  Group  representations can send the data in
  question to [7Xmailto:R.A.Wilson@qmul.ac.uk[0m.
  
  It is also possible to store "private" representations and programs in local
  directories,  and  to  use  them in the same way as the "official" data. See
  Chapter [14X3[0m for details.
  
  
  [1X1.9 What's New in [5XAtlasRep[1X, Compared to Older Versions?[0X
  
  
  [1X1.9-1 What's New in Version 1.4?[0X
  
  --    In  addition  to  the group orders that were added in version 1.3 (see
        Section  [14X1.9-3[0m),  also  many  orders  of  maximal  subgroups  are  now
        available.  These values occur in the records returned by [2XAtlasProgram[0m
        ([14X2.5-3[0m)  (for  the  case  of  [10X"maxes"[0m  type programs) and of the three
        argument  version of [2XAtlasGenerators[0m ([14X2.5-2[0m); now a [10Xsize[0m component may
        be bound. In these cases, the groups returned by [2XAtlasSubgroup[0m ([14X2.5-7[0m)
        have the [2XSize[0m ([14XReference: Size[0m) attribute set.
  
        For  this  feature,  the function [2XAGRGNAN[0m ([14X5.7-1[0m) was generalized, the
        function [2XAtlasOfGroupRepresentationsTestWords[0m ([14X5.8-6[0m) was improved for
        [10X"maxes"[0m        type       programs,       and       the       function
        [2XAtlasOfGroupRepresentationsTestSubgroupOrders[0m  ([14X5.8-2[0m)  for  preparing
        the  values  was  added;  this  function  serves also as a consistency
        check.
  
  --    The  information  about the number of maximal subgroups, if available,
        is now used in [2XDisplayAtlasInfo[0m ([14X2.5-1[0m).
  
  --    In  many  cases,  straight  line  programs for computing generators of
        maximal  subgroups  of  a group G, say, can in fact be used to compute
        also  generators  of maximal subgroups of downward extensions of G; if
        not  then it may suffice to extend the given straight line programs by
        additional                       generators,                       see
        [2XAtlasOfGroupRepresentationsTestCompatibleMaxes[0m ([14X5.8-4[0m).
  
        Currently  this  yields  more  than  200 more possibilities to compute
        maximal  subgroups,  this  means  a  growth  by  about 25 percent. For
        example,  all  maximal  subgroups  of  12.M_22  and 2.Fi_22 can now be
        accessed via [2XAtlasGenerators[0m ([14X2.5-2[0m).
  
        (Of  course this extension means only that one can access the straight
        line  programs  in  question  automatically  via the [5XGAP[0m interface. In
        principle  one  could  have  used  them  already before, by explicitly
        applying a straight line program for a factor group to generators of a
        group,  and  perhaps  adding some element in the kernel of the natural
        epimorphism.)
  
        For  this  feature,  information  about  the compatibility of standard
        generators   of   groups  and  their  factor  groups  was  added,  see
        [2XAtlasOfGroupRepresentationsTestStdCompatibility[0m ([14X5.8-3[0m).
  
  --    The  bibliographies  contained in the [5XATLAS[0m of Finite Groups [CCNPW85]
        and  in the [5XATLAS[0m of Brauer Characters [JLPW95] are now available, see
        Section [14X4.4[0m.
  
  --    If  the  [5XGAP[0m  package  [5XBrowse[0m  (see  [BL08])  is  loaded  then the new
        functions           [2XBrowseMinimalDegrees[0m          ([14X4.3-6[0m)          and
        [2XBrowseBibliographySporadicSimple[0m    ([14X4.4-1[0m)   are   available;   these
        functions  can  be  called  also  by  choosing  the corresponding menu
        entries    of    the   [5XBrowse[0m   application   [2XBrowseGapData[0m   ([14XBrowse:
        BrowseGapData[0m).
  
  --    The  function  [2XAtlasGroup[0m  ([14X2.5-6[0m) now admits also the return value of
        [2XOneAtlasGeneratingSetInfo[0m ([14X2.5-4[0m) as its argument.
  
  
  [1X1.9-2 What's New in Version 1.3.1?[0X
  
  This  version  was  mainly  released in order to fix a few problems. Now one
  does not get warnings about unbound variables when the package is loaded and
  the  [5XGAP[0m package [5XIO[0m [Neu07] is not available, and pathological situations in
  [2XFFMatOrPermCMtxBinary[0m  ([14X5.3-5[0m)  (concerning  extremely  short corrupted data
  files  and  different  byte  orderings  in  binary  files)  are handled more
  carefully.
  
  Besides this, the two functions [2XAtlasGroup[0m ([14X2.5-6[0m) and [2XAtlasSubgroup[0m ([14X2.5-7[0m)
  were  introduced,  and  the  extended function [2XQuaternionAlgebra[0m ([14XReference:
  QuaternionAlgebra[0m)  of  [5XGAP[0m 4.4.10 can now be used for describing base rings
  in [2XOneAtlasGeneratingSetInfo[0m ([14X2.5-4[0m) and [2XAllAtlasGeneratingSetInfos[0m ([14X2.5-5[0m).
  (This  is  the  reason  why  this  version  of the package requires at least
  version 4.4.10 of [5XGAP[0m.)
  
  
  [1X1.9-3 What's New in Version 1.3?[0X
  
  --    The  database  was extended, see Section [14X1.7-4[0m for the number and size
        of files.
  
  --    New data types and corresponding [5XGAP[0m objects have been introduced, for
        representing   semi-presentations,  presentations,  and  programs  for
        finding  standard  generators.  For details, see [2XAtlasProgram[0m ([14X2.5-3[0m),
        Chapter [14X4[0m, and Section [14X5.6[0m.
  
  --    The   records  returned  by  the  functions  [2XAtlasGenerators[0m  ([14X2.5-2[0m),
        [2XOneAtlasGeneratingSetInfo[0m   ([14X2.5-4[0m),   and  [2XAllAtlasGeneratingSetInfos[0m
        ([14X2.5-5[0m)  now contain the name and (if known) the order of the group in
        question,  and  also  components  describing the degree in the case of
        permutation  representations or the dimension and the base ring of the
        natural module in the case of matrix representations.
  
  --    For  many  of  the  groups,  information  about  the minimal degree of
        faithful  permutation  representations  and  the minimal dimensions of
        faithful   matrix   representations   in  various  characteristics  is
        available   for  [2XDisplayAtlasInfo[0m  ([14X2.5-1[0m),  [2XOneAtlasGeneratingSetInfo[0m
        ([14X2.5-4[0m), and [2XAllAtlasGeneratingSetInfos[0m ([14X2.5-5[0m), see also Section [14X4.3[0m.
        For  these  functions,  also properties such as [2XIsPrimeInt[0m ([14XReference:
        IsPrimeInt[0m)  can  be  used to describe the intended restriction of the
        output.
  
  --    One  can now use [2XPager[0m ([14XReference: Pager[0m) in [2XDisplayAtlasInfo[0m ([14X2.5-1[0m),
        see Section [14X1.7-5[0m.
  
        An  interactive alternative to [2XDisplayAtlasInfo[0m ([14X2.5-1[0m) is provided by
        the  function  [2XBrowseAtlasInfo[0m  ([14XBrowse: BrowseAtlasInfo[0m) from the new
        (recommended) [5XGAP[0m package [5XBrowse[0m [BL08].
  
  --    The      functions      [2XOneAtlasGeneratingSetInfo[0m      ([14X2.5-4[0m)     and
        [2XAllAtlasGeneratingSetInfos[0m  ([14X2.5-5[0m)  now  admit  also  a list of group
        names as the first argument.
  
  --    The  functions  for actually accessing the data are more flexible now,
        see Section [14X1.7-6[0m.
  
  --    For  transferring  remote  data, the [5XGAP[0m package [5XIO[0m [Neu07] can now be
        used   (and   is   recommended)   as   an  alternative  to  [11Xwget[0m,  see
        Section [14X1.7-3[0m.
  
  --    The  address  of  the data server has changed. Since the access to the
        server  is no longer possible via [11Xftp[0m, the mechanim used up to version
        1.2, which was based on [11Xftp[0m, had to be rewritten.
  
        The  main consequence of this change is that information about updates
        of  the  table  of contents is now provided at the package's homepage.
        This  means that on the one hand, now package users cannot [13Xcompute[0m the
        table of contents directly from the server data, but on the other hand
        the  update  information  can  be  [13Xdownloaded[0m without the necessity to
        install [11Xperl[0m.
  
        Another consequence is that the system program [11Xls[0m is no longer needed,
        see Section [14X1.9-5[0m.
  
  --    The package manual has been restructured, extended and improved. It is
        now based on the package [5XGAPDoc[0m [LN08].
  
  
  [1X1.9-4 What's New in Version 1.2?[0X
  
  Not much.
  
  The release of Version 1.2 became necessary first of all in order to provide
  a   package   version   that   is   compatible   with  [5XGAP[0m 4.4,  since  some
  cross-references into the [5XGAP[0m Reference Manual were broken due to changes of
  section  names.  Additionally,  several web addresses concerning the package
  itself were changed and thus had to be adjusted.
  
  This opportunity was used
  
  --    to  upgrade  the  administrational part for loading the package to the
        mechanism that is recommended for [5XGAP[0m 4.4,
  
  --    to  extend  the  test  suite, which now covers more consistency checks
        using the [5XGAP[0m Character Table Library [Bre04],
  
  --    to  make  the function [2XScanMeatAxeFile[0m ([14X5.3-1[0m) more robust, due to the
        fact  that the [5XGAP[0m function [2XPermList[0m ([14XReference: PermList[0m) now returns
        [9Xfail[0m instead of raising an error,
  
  --    to  change  the way how representations with prescribed properties are
        accessed  (the  new  function [2XOneAtlasGeneratingSetInfo[0m ([14X2.5-4[0m) is now
        preferred     to     the     former     [10XOneAtlasGeneratingSet[0m,     and
        [2XAllAtlasGeneratingSetInfos[0m  ([14X2.5-5[0m) has been added in order to provide
        programmatic  access  in  parallel  to the human readable descriptions
        printed by [2XDisplayAtlasInfo[0m ([14X2.5-1[0m)),
  
  --    and last but not least to include the current table of contents of the
        underlying database.
  
  For  [5XAtlasRep[0m  users, the new feature of [5XGAP[0m 4.4 is particularly interesting
  that due to better kernel support, reading large matrices over finite fields
  is now faster than it was in [5XGAP[0m 4.3.
  
  
  [1X1.9-5 What's New in Version 1.1?[0X
  
  The  biggest change w.r.t. Version 1.1 is the addition of private extensions
  (see  Chapter [14X3[0m). It includes a new "free format" for straight line programs
  (see  Section [14X3.2[0m).  Unfortunately, this feature requires the system program
  [11Xls[0m,  so  it  may  be  not  available  for example under MS Windows operating
  systems. [But see Section [14X1.9-3[0m.]
  
  In order to admit the addition of other types of data, the implementation of
  several functions has been changed. Data types are described in Section [14X5.5[0m.
  An  example  of  a  new  data  type  are  quaternionic  representations (see
  Section [14X5.6[0m). The user interface itself (see Chapter [14X2[0m) remained the same.
  
  As  an alternative to [10Xperl[0m, one can use [10Xwget[0m now for transferring data files
  (see [14X1.7[0m).
  
  Data  files can be read much more efficiently in [5XGAP[0m 4.3 than in [5XGAP[0m 4.2. In
  Version 1.1  of  the  [5XAtlasRep[0m  package,  this  feature  is used for reading
  matrices  and  permutations  in  [5XMeatAxe[0m  text  format  with [2XScanMeatAxeFile[0m
  ([14X5.3-1[0m).  As  a  consequence,  (at  least)  [5XGAP[0m 4.3 is required for [5XAtlasRep[0m
  Version 1.1.
  
  The     new     [10Xcompress[0m     component     of     the     global    variable
  [2XAtlasOfGroupRepresentationsInfo[0m  ([14X5.1-5[0m)  allows  one  to  store  data files
  automatically in [11Xgzip[0mped form.
  
  For  matrix  representations  in  characteristic  zero,  invariant forms and
  generators for the centralizer algebra are now accessible in [5XGAP[0m if they are
  contained  in  the  source  files  --this  information  had  been ignored in
  Version 1.0 (see [2XAtlasOfGroupRepresentationsTestTableOfContentsRemoteUpdates[0m
  ([14X1.6-4[0m) for necessary updates).
  
  Additional information is now available via the internet (see [14X1.3[0m).
  
  The update facilities have been extended (see [14X1.6[0m).
  
  The  manual  is  now  distributed  also in pdf and HTML format; on the other
  hand, the PostScript format manual is no longer contained in the archives.
  
  Apart  from these changes, a few minor bugs in the handling of [5XMeatAxe[0m files
  have  been  fixed,  typos  in the documentation have been corrected, and the
  syntax checks for [5XATLAS[0m straight line programs (see [14X5.4[0m) have been improved.
  
  
  [1X1.10 Acknowledgments[0X
  
  The  perl  script  that  had  been  used  for  fetching  remote  data  until
  version 1.2  had  been  kindly  provided by Frank Lübeck and Max Neunhöffer.
  Thanks  also  to  Greg  Gamble  and  Alexander  Hulpke  for  technical hints
  concerning "standard" perl.
  
  Ulrich Kaiser helped with preparing the package for MS Windows.
  
  The idea to support private extensions of the package (see Chapter [14X3[0m) is due
  to  Klaus  Lux.  He  used a preliminary version of [5XAtlasRep[0m Version 1.1, and
  helped to fix several bugs.
  
  The   functions   [2XCMtxBinaryFFMatOrPerm[0m  ([14X5.3-4[0m)  and  [2XFFMatOrPermCMtxBinary[0m
  ([14X5.3-5[0m) were contributed by Frank Lübeck.
  
  The  [5XGAPDoc[0m package [LN08], which is used for processing the package manual,
  was written by Frank Lübeck and Max Neunhöffer.
  
  The  [5XGAP[0m package [5XIO[0m [Neu07], which is recommended for transferring data, was
  written by Max Neunhöffer.
  
  Max  has  also  suggested the generalization of the data access described in
  Section [14X1.7-6[0m.
  
  Gunter  Malle had suggested to make the information about representations of
  minimal degree accessible.
  
