Revision history.

0.69 Fri, 20 Apr 2007 17:23:21 -0400
  - Works with GAP 4.4.9
  - Improved IsGraphicArrangement slightly
  - Add H_3 arrangement to KnownHyperplaneArrangementTypes
  - fix bug where taking a generic slice could loop forever

0.68.1 Mon, 20 Mar 2006 15:35:41 -0500
  - BUGFIX: LCSQuotientRanks incorrectly computed \phi_1 for decomposable arrangements

0.68 Sat, 11 Mar 2006 17:07:29 -0500
  - (!!) fixed insanity with fox calculus argument ordering

    These changes are likely to have broken older code. Review all
    applications of fox derivative.

    Originally, fox calculus functions tried to follow mathematical style
    where functions are applied right to left. That was just too annoying
    and counter-intuitive in a computing environment. All lists of
    operations now start at the beginning of the list and proceed from
    there.

     * H_(i,j) = __FoxHessian(e) = __FoxJacobian( de/dx_i )
     * _fox_derivative(e, [a,b,c]) = d/dc( d/db( d/da(e) ) )
     * __FoxDerivative(e, [i], [f, g, h]) = h( g( f( de/di ) ) )

  - RENAME LCM_INT -> _arr_LCM_INT
  - RENAME PolynomialGCD -> MonomialDenominatorLCM
  - Expand several functions to behave properly on constants:
    ConstantTerm, NrIndeterminates, IndeterminateNumbers, Indeterminates
  - MonomialLCM and MonomialGCD use Reduce(L,MonomialLCM2) and Reduce(L,MonomialGCD2)
    so that we can operate on constants as well

0.67 Sun, 18 Sep 2005 23:40:11 -0400
  - Conversion to Inline documentation
  - many Documentation improvements and corrections
  - complete rewrite of matroid.gi
  - several new polynomial functions
  - Add support and tests for Decomposable arrangements
  - LCSQuotients replaces LCSQuotientRanks
  - AlexMat: AlexanderMatrix with magic
  - RENAME Graph -> ArrGraph to prevent conflict with GRAPE

0.66 Sat, 07 May 2005 21:04:13 -0400
  - Fix several bugs which caused fundamental groups to be incorrect
  - Added lots of tests to prevent future breakage

0.65 Sat, 02 Oct 2004 22:05:04 -0400
  - various bug fixes
  - First public release of (still experimental) code for real
    (non-rational) and hypersolvable arrangements

0.63 Mon, 27 Sep 2004 00:24:50 -0400
  : unreleased
  - configure, Makefile, README added to arrangement package
  - minor code cleanup
  - Generalize FundamentalGroup computation to work for Real (non-rational) arrangements

0.62 Sat, 25 Sep 2004 17:09:17 -0400
  : unreleased
  - minor bugfixes
  - rename ValueRing -> BaseField
  - Prepare BaseField and CoefficientsRing support
  - creation of Hypersolvable functions

0.6 Sun Aug 1 03:44:51 2004
  - some bugfixes in IntersectionLattice and FundamentalGroup

0.59 Sat Jul 31 20:41:58 2004
  - NEW FUNCTIONS: AugmentedFoxJacobian, AugmentedFoxHessian, AugmentedAlexanderMatrix
  - GAP4.3-hacks.g for backwards compatibility
  - lots of fixes for affine arrangements

0.56 Tue Jul 27 20:10:26 2004
  - NEW FUNCTION: PolynomialLCD
  - Added many Fox Calculus tests
  - Fixed bugs from creation of those tests

0.55 Mon Jul 26 23:26:08 2004
  - Major overhaul of Fox Calculus code
  - Many bugfixes and documentation updates

0.1 Sat Jun 14 01:40:40 2003
  - initial creation