[GAP Forum] Release Announcement: GAP 4.4

[Alexander Hulpke]

Dear Gap-Forum,

GAP 4.4 is available! It contains a variety of new features, improved
algorithms and new programming tools. A detailed outline is included
below.

We recommend all GAP 4 users to upgrade to GAP 4.4 and we wish you fun
and success in using GAP.

You can download the new version of GAP from 
       http://www.gap-system.org

The GAP group

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New Mathematical Features
-------------------------

* New Algorithms and Functions in GAP

  - Groebner Bases: 

    Buchberger's algorithm to compute Groebner Bases has been implemented 
    in GAP. (By A. Hulpke)

    For large scale Groebner Basis computations there also is an interface 
    to the Singular system available in the 'Singular' Package. 
    (By M. Costantini and W. de Graaf)  

  - Algebraic Field Extension: 

    New methods for factorizing polynomials over algebraic extensions of 
    the rationals have been implemented in GAP. (By A. Hulpke)

    For more functionality to compute with algebraic number fields there 
    is an interface to the Kant system available in the 'Alnuth' Package. 
    (By B. Assmann and B. Eick)

  - Galois Groups: 

    A method for computing the Galois group of a rational polynomial has 
    been implemented in GAP.  (By A. Hulpke)

  - Finite Groups: 

    A new operation and a new method to compute the minimal normal subgroups 
    of a finite group and a method to determine the socle of a finite group
    has been installed. (By B. Hoefling)

  - Permutation Groups:

    A fast method for recognizing whether a permutation group is symmetric 
    or alternating in its natural representation is available now. 
    (By A. Seress)

  - Brauer Tables: 

    The algorithm for 'BrauerCharacterValue' has been extended to the case 
    where the splitting field is not supported in GAP. (By T. Breuer) 

    Brauer tables of direct products can now be constructed from the 
    known Brauer tables of the direct factors. (By T. Breuer)

  - Vector spaces: 

    Basic support for vector spaces of rational functions and of uea 
    elements is available now in GAP. (By T. Breuer and W. de Graaf)

  - Integer matrices:
  
    Various new functions for computations with integer matrices are
    available, such as methods for computing normal forms of integer 
    matrices as well as nullspaces or solutions systems of equations.
    (By W. Nickel and F. Gaehler)
 
  - Meataxe:

    It is now possible to compute invariant forms and orthogonal signs of
    modules. (By D. Holt and J. Thackray)

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* New Packages for GAP

  The following new Packages have been accepted.

  - LAGUNA: Computing with Lie Algebras and Units of Group Algebras. 
    By V. Bovdi, A. Konovalov, R. Rossmanith, C. Schneider.

  - NQ: The ANU Nilpotent Quotient Algorithm. 
    By W. Nickel. 

  - KBMAG: Knuth-Bendix for Monoids and Groups.
    By D. Holt.

  - QuaGroup: Computing with Quantized Enveloping Algebras.
    By W. de Graaf.

  - AlNuTh: Algebraic Number Theory and an Interface to the Kant System.
    By B. Assmann and B. Eick
 
  - Polycyclic: Computation with Polycyclic Groups.
    By B. Eick and W. Nickel

  - Sonata: Construction and analysis of finite nearrings.
    By E. Aichinger, F. Binder, J. Ecker, P. Mayr, C. Noebauer

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* Performance Enhancements

  - Character Theory:
    The computation of irreducible representations and irreducible 
    characters using the Baum-Clausen algorithm and the implementation of 
    the Dixon-Schneider algorithm have been speeded up. The algorithm for 
    'PossibleClassFusions' has been changed: the efficiency has been 
    improved and a new criterion is used. The algorithm for 
    'PossibleFusionsCharTableTom' has been speeded up. The method for 
    'PrimeBlocks' has been improved following a suggestion of H. Pahlings.

  - Symmetric Groups
    New improved methods for normalizer and subgroup conjugation in Sn have
    been installed and new improved methods for IsNaturalSn/An have been 
    implemented. These improve the available methods when groups of large 
    degrees are given. 

  - Permutation Groups: 
    The partition split method used in the permutation backtrack is now
    in the kernel. Transversal computations in large permutation groups
    are improved. The decomposition of a permutation as a word in the
    generators now produces substantially shorter words: for example, the
    words have lengths about 100 for the Rubics Cube group.

  - Matrix Groups: 
    The membership test in SP and SU has been improved using the invariant 
    forms underlying these groups. 

  - Finite groups: 
    An improvement for the cyclic extension method has been implemented.

  - Matrices: 
    A better method for MinimalPolynomial for finite field matrices has been 
    implemented. 

  - Polynomials: 
    The display has changed and the arithmetic of multivariate polynomials 
    has been improved. 

  - LogMod: 
    Uses now Pollard's rho method combined with the Pohlig/Hellmann approach. 
    (By Sean Gage)

  - Lists: 
    Various functions for sets and lists have been improved following
    suggestions of L. Teirlinck. These include: Sort, Sortex, SortParallel,
    SortingPerm, NrArrangements. 

  - Finite Dimensional Algebras: 
    The methods for 'StructureConstantsTable' and 'GapInputSCTable' have 
    been improved in the case of a known (anti-) symmetry following a 
    suggestion of M. Costantini. 

Unless otherwise stated, the improvements listed in this Section have been 
implemented by T. Breuer and A. Hulpke.

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* Technical changes in GAP and new programming tools

  - IsSimple: Returns false now for the trivial group. 
  - PrimeBlocks: The output format has changed. 
  - Division Rings: These are implemented as 'IsRingWithOne' now. 
  - DirectSumOfAlgebras: Pth power maps are compatible with the input now.
  - EnumeratorByFunctions: A new tool to create enumerators.
  - IteratorByFunctions: A new tool to create iterators.

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* Bug Fixes

   It remains to mention that GAP 4.4 includes fixes for all bugs which 
   had been reported before the deadline for the release. 

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New Programming and User Features
---------------------------------

  - Workspaces: The 2GB limit has been removed and version numbers have 
                been introduced. (By S. Linton and B. Hoefling)
 
  - Types: The limit on the total number of types created in a session 
           has been removed. (By S. Linton)

  - Packages: There is a new mechanism for loading packages available.
              Packages need a file PackageInfo.g now. (By T. Breuer and
              F. Luebeck)

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Upwards Compatibility 
---------------------

  The mechanism for the loading of Packages has changed. Packages require 
  a file PackageInfo.g now. These new PackageInfo.g files are available 
  for all accepted and deposited Packages within GAP 4.4.

  Apart from the Package loading, there are only some other very minor 
  changes (e.g.  the trivial group is not a simple group in GAP any longer)
  which are not compatible with GAP 4.3.

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License and Installing GAP 4.4
------------------------------

   GAP is free software which is distributed under the GNU general public
   licence. You can get GAP 4.4 from 
       - http://www.gap-system.org
       - ftp://ftp.gap-system.org in the directory pub/gap/gap4.

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Acknowledgements
---------------

* Personal Support

  The members of the GAP development team are working on GAP as a part of 
  their research or in their free time. The GAP development team has members 
  all over the world and thus GAP can be considered as a world wide joint 
  research project. A list of the members of the GAP development team can 
  be found in the Tutorial manual of GAP. 

  A significant part of the functionality of GAP is available in the GAP 
  packages. These are independently developed packages of code with their 
  own author lists. A detailed list of the available GAP packages can be 
  found on the GAP web pages.
  
  Finally, there is a long list of collaborateurs and users of GAP. The 
  feedback and constructive critism of these people has helped to fix bugs 
  and to improve the system. Many thanks are due to all these people.

* Financial Support

  We acknowledge with gratitude the support of the development of GAP
  provided by a variety of funding bodies. Details can be found on the GAP
  web pages.

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Bugfixes
--------

  If you have followed the releases of GAP over the last years you might
  have noted that a first bugfix typically comes early after a release. This
  is despite of extensive testing, but unfortunately reflects the limited
  size of the developer group compared to the user community. We simply
  might not have thought of doing certain things.  If the experience of
  previous releases holds, we therfore will have a first update within the
  next two or three weeks. You might want to plan accordingly.