Welcome To Our Shell

Mister Spy & Souheyl Bypass Shell

  
  9 Changes from Earlier Versions
  
  
  9.1 Earlier Changes
  
  The most important changes between GAP 4.2 and GAP 4.3 were:
  
      The performance of several routines has been substantially improved.
  
      The  functionality  in  the  areas of finitely presented groups, Schur
        covers and the calculation of representations has been extended.
  
      The  data  libraries  of  transitive  groups,  finite  integral matrix
        groups, character tables and tables of marks have been extended.
  
      The  Windows  installation  has been simplified for the case where you
        are installing GAP in its standard location.
  
      Many bugs have been fixed.
  
  The most important changes between GAP 4.1 and GAP 4.2 were:
  
      A  much  extended  and  improved  library  of  small groups as well as
        associated IdGroup (smallgrp: IdGroup) routines.
  
      The  primitive  groups  library  has been made more independent of the
        rest of GAP, some errors were corrected.
  
      New  (and  often  much  faster)  infrastructure for orbit computation,
        based on a general dictionary abstraction.
  
      New functionality for dealing with representations of algebras, and in
        particular for semisimple Lie algebras.
  
      New  functionality  for binary relations on arbitrary sets, magmas and
        semigroups.
  
      Bidirectional  streams, allowing an external process to be started and
        then controlled interactively by GAP
  
      A  prototype  implementation  of  algorithms  using  general  subgroup
        chains.
  
      Changes in the behavior of vectors over small finite fields.
  
      A  fifth  book  New  features for Developers has been added to the GAP
        manual.
  
      Numerous bug fixes and performance improvements
  
  The changes between the final release of GAP 3 (version 3.4.4) and GAP 4 are
  wide-ranging.  The  general  philosophy of the changes is two-fold. Firstly,
  many  assumptions  in  the  design  of  GAP  3 revealed its authors' primary
  interest  in  group theory, and indeed in finite group theory. Although much
  of  the  GAP 4 library is concerned with groups, the basic design now allows
  extension  to  other  algebraic structures, as witnessed by the inclusion of
  substantial  bodies  of  algorithms  for computation with semigroups and Lie
  algebras.  Secondly,  as  the  scale of the system, and the number of people
  using  and  contributing  to  it  has  grown, some aspects of the underlying
  system  have  proved to be restricting, and these have been improved as part
  of  comprehensive  re-engineering  of  the system. This has included the new
  method  selection  system, which underpins the library, and a new, much more
  flexible, GAP package interface.
  
  Details  of  these  changes  can be found in the document Migrating to GAP 4
  available          at          the          GAP         website,         see
  https://www.gap-system.org/Gap3/migratedoc.pdf.
  
  It is perhaps worth mentioning a few points here.
  
  Firstly,  much  remains  unchanged, from the perspective of the mathematical
  user:
  
      The  syntax  of that part of the GAP language that most users need for
        investigating mathematical problems.
  
      The great majority of function names.
  
      Data libraries and the access to them.
  
  A number of visible aspects have changed:
  
      Some  function names that need finer specifications now that there are
        more structures available in GAP.
  
      The  access  to  information  already  obtained  about  a mathematical
        structure.  In GAP 3 such information about a group could be looked up
        by  directly  inspecting  the group record, whereas in GAP 4 functions
        must be used to access such information.
  
  Behind the scenes, much has changed:
  
      A  new  kernel,  with  improvements  in  memory  management and in the
        language  interpreter,  as  well  as  new  features  such as saving of
        workspaces and the possibility of compilation of GAP code into C.
  
      A  new  structure  to  the  library,  based upon a new type and method
        selection  system,  which  is  able  to  support  a  broader  range of
        algebraic computation and to make the structure of the library simpler
        and more modular.
  
      New and faster algorithms in many mathematical areas.
  
      Data  structures  and algorithms for new mathematical objects, such as
        algebras and semigroups.
  
      A  new  and  more  flexible  structure  for  the  GAP installation and
        documentation,  which  means,  for example, that a GAP package and its
        documentation can be installed and be fully usable without any changes
        to the GAP system.
  
  Very few features of GAP 3 are not yet available in GAP 4.
  
      Not  all  of  the  GAP 3 packages have yet been converted for use with
        GAP 4.
  
      The  library  of crystallographic groups which was present in GAP 3 is
        now       part       of       a       GAP 4      package      CrystCat
        (https://www.gap-system.org/Packages/crystcat.html)  by  V. Felsch and
        F. Gähler.