CONTRIBUTORS

move countability proof from Rational to Countable; add instance rat :: countable

For the purposes of the license agreement in the file COPYRIGHT, a
'contributor' is anybody who is listed in this file (CONTRIBUTORS) or
who is listed as an author in one of the source files of this Isabelle
distribution.


Contributions to this Isabelle version
--------------------------------------

* February 2008: Timothy Bourke, NICTA
  "solves" criterion for find_theorems and auto_solve option

* December 2008: Clemens Ballarin, TUM
  New locale implementation.

* December 2008: Armin Heller, TUM and Alexander Krauss, TUM
  Method "sizechange" for advanced termination proofs.

* November 2008: Timothy Bourke, NICTA
  Performance improvement (factor 50) for find_theorems.

* 2008: Florian Haftmann, TUM
  Various extensions and restructurings in HOL, improvements
  in evaluation mechanisms, new module binding.ML for name bindings.

* October 2008: Fabian Immler, TUM
  ATP manager for Sledgehammer, based on ML threads instead of Posix
  processes.  Additional ATP wrappers, including remote SystemOnTPTP
  services.

* August 2008: Fabian Immler, TUM
  Vampire wrapper script for remote SystemOnTPTP service.


Contributions to Isabelle2008
-----------------------------

* 2007/2008:
  Alexander Krauss, TUM and Florian Haftmann, TUM and Stefan Berghofer, TUM
  HOL library improvements.

* 2007/2008: Brian Huffman, PSU
  HOLCF library improvements.

* 2007/2008: Stefan Berghofer, TUM
  HOL-Nominal package improvements.  

* March 2008: Markus Reiter, TUM
  HOL/Library/RBT: red-black trees.

* February 2008: Alexander Krauss, TUM and Florian Haftmann, TUM and
  Lukas Bulwahn, TUM and John Matthews, Galois:
  HOL/Library/Imperative_HOL: Haskell-style imperative data structures
  for HOL.

* December 2007: Norbert Schirmer, Uni Saarbruecken
  Misc improvements of record package in HOL.

* December 2007: Florian Haftmann, TUM
  Overloading and class instantiation target.

* December 2007: Florian Haftmann, TUM
  New version of primrec package for local theories.

* December 2007: Alexander Krauss, TUM
  Method "induction_scheme" in HOL.

* November 2007: Peter Lammich, Uni Muenster
  HOL-Lattice: some more lemmas.


Contributions to Isabelle2007
-----------------------------

* October 2007: Norbert Schirmer, TUM / Uni Saarbruecken
  State Spaces: The Locale Way (in HOL).

* October 2007: Mark A. Hillebrand, DFKI
  Robust sub/superscripts in LaTeX document output.

* August 2007: Jeremy Dawson, NICTA and Paul Graunke, Galois and Brian
    Huffman, PSU and Gerwin Klein, NICTA and John Matthews, Galois
  HOL-Word: a library for fixed-size machine words in Isabelle.

* August 2007: Brian Huffman, PSU
  HOL/Library/Boolean_Algebra and HOL/Library/Numeral_Type.

* June 2007: Amine Chaieb, TUM
  Semiring normalization and Groebner Bases.
  Support for dense linear orders.

* June 2007: Joe Hurd, Oxford
  Metis theorem-prover.

* 2007: Kong W. Susanto, Cambridge
  HOL: Metis prover integration.

* 2007: Stefan Berghofer, TUM
  HOL: inductive predicates and sets.

* 2007: Norbert Schirmer, TUM
  HOL/record: misc improvements.

* 2006/2007: Alexander Krauss, TUM
  HOL: function package and related theories on termination.

* 2006/2007: Florian Haftmann, TUM
  Pure: generic code generator framework.
  Pure: class package.
  HOL: theory reorganization, code generator setup.

* 2006/2007: Christian Urban, TUM and Stefan Berghofer, TUM and
    Julien Narboux, TUM
  HOL/Nominal package and related tools.

* November 2006: Lukas Bulwahn, TUM
  HOL: method "lexicographic_order" for function package.

* October 2006: Stefan Hohe, TUM
  HOL-Algebra: ideals and quotients over rings.

* August 2006: Amine Chaieb, TUM
  Experimental support for generic reflection and reification in HOL.

* July 2006: Rafal Kolanski, NICTA
  Hex (0xFF) and binary (0b1011) numerals.

* May 2006: Klaus Aehlig, LMU
  Command 'normal_form': normalization by evaluation.

* May 2006: Amine Chaieb, TUM
  HOL-Complex: Ferrante and Rackoff Algorithm for linear real
  arithmetic.

* February 2006: Benjamin Porter, NICTA
  HOL and HOL-Complex: generalised mean value theorem, continuum is
  not denumerable, harmonic and arithmetic series, and denumerability
  of rationals.

* October 2005: Martin Wildmoser, TUM
  Sketch for Isar 'guess' element.


Contributions to Isabelle2005
-----------------------------

* September 2005: Lukas Bulwahn and Bernhard Haeupler, TUM
  HOL-Complex: Formalization of Taylor series.

* September 2005: Stephan Merz, Alwen Tiu, QSL Loria
  Components for SAT solver method using zChaff.

* September 2005: Ning Zhang and Christian Urban, LMU Munich
  A Chinese theory.

* September 2005: Bernhard Haeupler, TUM
  Method comm_ring for proving equalities in commutative rings.

* July/August 2005: Jeremy Avigad, Carnegie Mellon University
  Various improvements of the HOL and HOL-Complex library.

* July 2005: Florian Zuleger, Johannes Hoelzl, and Simon Funke, TUM
  Some structured proofs about completeness of real numbers.

* May 2005: Rafal Kolanski and Gerwin Klein, NICTA
  Improved retrieval of facts from theory/proof context.

* February 2005: Lucas Dixon, University of Edinburgh
  Improved subst method.

* 2005: Brian Huffman, OGI
  Various improvements of HOLCF.
  Some improvements of the HOL-Complex library.

* 2005: Claire Quigley and Jia Meng, University of Cambridge
  Some support for asynchronous communication with external provers
  (experimental).

* 2005: Florian Haftmann, TUM
  Contributions to document 'sugar'.
  Various ML combinators, notably linear functional transformations.
  Some cleanup of ML legacy.
  Additional antiquotations.
  Improved Isabelle web site.

* 2004/2005: David Aspinall, University of Edinburgh
  Various elements of XML and PGIP based communication with user
  interfaces (experimental).

* 2004/2005: Gerwin Klein, NICTA
  Contributions to document 'sugar'.
  Improved Isabelle web site.
  Improved HTML presentation of theories.

* 2004/2005: Clemens Ballarin, TUM
  Provers: tools for transitive relations and quasi orders.
  Improved version of locales, notably interpretation of locales.
  Improved version of HOL-Algebra.

* 2004/2005: Amine Chaieb, TUM
  Improved version of HOL presburger method.

* 2004/2005: Steven Obua, TUM
  Improved version of HOL/Import, support for HOL-Light.
  Improved version of HOL-Complex-Matrix.
  Pure/defs: more sophisticated checks on well-formedness of overloading.
  Pure/Tools: an experimental evaluator for lambda terms.

* 2004/2005: Norbert Schirmer, TUM
  Contributions to document 'sugar'.
  Improved version of HOL/record.

* 2004/2005: Sebastian Skalberg, TUM
  Improved version of HOL/Import.
  Some internal ML reorganizations.

* 2004/2005: Tjark Weber, TUM
  SAT solver method using zChaff.
  Improved version of HOL/refute.