ANNOUNCE

Type inference bug in Isar attributes "where" and "of" fixed.

Subject: Announcing Isabelle2003
To: [e-mail]

Isabelle2003 is now available.

This release provides many improvements and a few substantial advances over
Isabelle2002.  The most prominent highlights of Isabelle2003 are as follows
(see the NEWS of the distribution for more details):

 * New framework for extracting programs from constructive proofs in HOL.
   (Berghofer)

 * Improved simplifier. The premises of a goal are completely
   interreduced, ie simplified wrt each other. (Berghofer)

 * Presburger arithmetic. Method arith can deal with quantified formulae over
   nat and int, and with mod, div and dvd wrt a numeral.  (Chaieb and Nipkow)

 * New command to find all rules whose conclusion matches the current goal.

 * New command to trace why unification failed.

 * Locales (named proof contexts).  The new implementation is fully
   integrated with Isar's notion of proof context, and locale specifications
   produce predicate definitions that allow to work with locales in more
   flexible ways. (Wenzel)

 * HOL/Algebra: proofs in classical algebra.  Intended as a base for all
   algebraic developments in HOL.  Currently covers group and ring theory.
   (Ballarin, Kammüller, Paulson)

 * HOL/Complex defines the type "complex" of the complex numbers, with numeric
   constants and some complex analysis, including nonstandard analysis.  The
   image HOL-Complex should be used for developments involving the real
   numbers too.  Gauge integration and hyperreal logarithms have recently
   been added. (Fleuriot)

 * HOL/NumberTheory: added Gauss's law of quadratic reciprocity. (Avigad,
   Gray and Kramer)

 * ZF/Constructible: Gödel's proof of the relative consistency of the axiom
   of choice is mechanized using Isabelle/ZF, following Kunen's well-known
   textbook "Set Theory". (Paulson)

You may get Isabelle2003 from the following mirror sites:

  Cambridge (UK)    http://www.cl.cam.ac.uk/Research/HVG/Isabelle/dist/
  Munich (Germany)  http://isabelle.in.tum.de/dist/

Gerwin Klein
Tobias Nipkow
Larry Paulson