Overview of changes in PerMuVAR 1.0.0:
======================================

First beta release for MuPAD 2.0. No changes in functionalities.

IMPORTANT NOTE: This new version is incompatible with MuPAD 1.4.
Unless someone discovers a catastrophic bug in PerMuVAR 0.999.3, there
won't be any new release of PerMuVAR for MuPAD 1.4.

All of this should be fairly transparent for the user. Most visible
change: degreeBound and degreeLowerBound are methods now, and should
be called as follow: IG::degreeBound(). See the tutorial which has
been updated. See the documentation of MuPAD for the general changes.

Most of the work was to adapt PerMuVAR for MuPAD 2.0. This was the
occasion for a big cleanup, and the enhanced debugging tools of MuPAD
2.0 catched a lot of little creeping bugs. Since the programming
language is also much cleaner (lexical scoping, ...), PerMuVAR is
likely to be more robust now. The test suite has been improved, so
hopefully most bugs introduced by the translation process have been
found. I cross my fingers.

Some known bugs were also fixed, and the version of GLIP distributed
with PerMuVAR has been adapted for MuPAD 2.0. There will be soon a
separate release of GLIP containing those changes.

PerMuVAR also contains an enhanced version of the MuPAD combinat
package, which will be included in a later version of MuPAD (2.1?)


Overview of changes in PerMuVAR 0.999.3:
========================================

Bug fix release. Main bug: the computation of secondary invariants for
non transitive groups did not work due to an incorrect construction of
elementary symmetric polynomials and symmetric powersums.


Overview of changes in PerMuVAR 0.999.2:
========================================

Includes GLIP-0.4fix1 (bugfix release: now compiles with egcs 2.91.66).
Bug fixes (time formating in statistics, ...).
Improved installation procedure and documentation.
Improved degree bound for Gorenstein invariant rings.


Overview of changes in PerMuVAR 0.999.1:
========================================

This version of PerMuVAR is stable. I still classify it as beta since
there are some new experimental features. Also, though in essence it
should be platform independent, I haven't had enough experience of use
outside of GNU/Linux. Finally, some routines may be renamed if users
come up with better suggestions.

Except for bug fixes, this will be the last release for MuPAD 1.4.2.
From now on, I want to concentrate on the first official release 1.0,
for MuPAD 2, which will be available in a month or so.

New features:
 - New algorithm for computation of minimal generating sets.
   Advantages:
    - Directly provides a minimal generating set.
    - No Gröbner basis computations. Pure linear algebra inside
      the invariant ring.
    - Reasonably fast and memory efficient. For small groups, it's
      not completely ridiculous compared to Magma, and can deal, at
      least partially, with bigger groups. See the file Benchmark.
    - Does not require the computation nor knowledge of primary invariants
      (however, knowing the degrees of the primary invariants can help
      improving the degree bound).
    - Characteristic free (experimental!)
    - Can be called directly for degree d, without previous knowledge
      of smaller degrees (except for the structure of the initial poset).
    - Could be parallelized.
   Remark:
    - The algorithm in itself is correct. However, it currently uses
      some optimizations which I haven't finished to prove correct yet.
 - Generation test; computations modulo the decomposable invariants.
 - Computation of a SAGBI basis.
 - Experimental support for non-zero characteristic computations.
 - New properties: isModular, isCohenMacaulay and isGorenstein.

Enhancements:
 - Easy and standard installation procedure (using automake/autoconf).
 - Stable and integrated support for computations with the chain product
   (Hironaka decompositions, ...).
 - Use of the C++ library GLIP for computations of the underlying
   isomorphism problems. This is much faster, and deprecates the
   use of remember tables for those computations, which saves a
   lot of memory. Default (slow) routines are provided in pure
   MuPAD in case GLIP does not work on some platform. PerMuVAR does
   not need any more a separate program to generate monomials up to
   an isomorphism. All the Perl crap -> trash bin.
 - Better degree bound: use of all the general results I know of ...

Overview of changes in PerMuVAR 0.192:
======================================

 - Compact data structure for invariants using orbit sums, with
   usual arithmetic operation.
 - Hilbert series, weight enumerations, counting of secondary
   invariants, estimation of the degree bound, ...
 - Computation of Hironaka decompositions, secondary invariants, and
   irreducible secondary invariants, using the classical
   linear-algebra algorithm.
   The primary invariants are not computed. The user can provide them
   or, by default, the symmetric powersums are used.
 - Experimental support for the chain product