## Credits: versions 7

The version V7 is a new implementation started in September 1999 by Jean-Christophe Filliâtre. This is a major revision with respect to the internal architecture of the system. The Coq version 7.0 was distributed in March 2001, version 7.1 in September 2001, version 7.2 in January 2002 and version 7.3 in May 2002.
Jean-Christophe Filliâtre designed the architecture of the new system, he introduced a new representation for environments and wrote a new kernel for type-checking terms. His approach was to use functional data-structures in order to get more sharing, to prepare the addition of modules and also to get closer to a certified kernel.
Hugo Herbelin introduced a new structure of terms with local definitions. He introduced ``qualified'' names, wrote a new pattern-matching compilation algorithm and designed a more compact logical consistency check algorithm. He contributed to the simplification of Coq internal structures and the optimisation of the system. He added basic tactics for forward reasoning and coercions in patterns.
David Delahaye introduced a new language for tactics. General tactics using pattern-matching on goals and context can directly be written from the Coq toplevel. He also provided primitives for the design of user-defined tactics in Caml.
Micaela Mayero contributed the library on real numbers. Olivier Desmettre extended this library with axiomatic trigonometric functions, square, square roots, finite sums, Chasles property and basic plane geometry.
Jean-Christophe Filliâtre and Pierre Letouzey redesigned a new extraction procedure from Coq terms to Caml or Haskell programs. This new extraction procedure, unlike the one implemented in previous version of Coq is able to handle all terms in the Calculus of Inductive Constructions, even involving universes and strong elimination. P. Letouzey adapted user contributions to extract ML programs when it was sensible. Jean-Christophe Filliâtre wrote `coqdoc`, a documentation tool for Coq libraries usable from version 7.2.
Bruno Barras improved the reduction algorithms efficiency and the confidence level in the correctness of Coq critical type-checking algorithm.
Yves Bertot designed the `SearchPattern` and `SearchRewrite` tools and the support for the pcoq interface (`http://www-sop.inria.fr/lemme/pcoq/`).
Micaela Mayero and David Delahaye introduced a decision tactic for commutative fields.
Christine Paulin changed the elimination rules for empty and singleton propositional inductive types.
Loïc Pottier developed a tactic solving linear inequalities on real numbers.
Pierre Crégut developed a new version based on reflexion of the Omega decision tactic.
Claudio Sacerdoti Coen designed an XML output for the Coq modules to be used in the Hypertextual Electronic Library of Mathematics (HELM cf `http://www.cs.unibo.it/helm`).
A library for efficient representation of finite sets by binary trees contributed by Jean Goubault was integrated in the basic theories.
The development was coordinated by C. Paulin.
Many discussions within the Démons team and the LogiCal project influenced significantly the design of Coq especially with J. Chrzaszcz, J. Courant, P. Courtieu, J. Duprat, J. Goubault, A. Miquel, C. Marché, B. Monate and B. Werner.
Intensive users suggested improvements of the system : Y. Bertot, L. Pottier, L. Théry , P. Zimmerman from INRIA C. Alvarado, P. Crégut, J.-F. Monin from France Telecom R & D.
Orsay, May. 2002
Hugo Herbelin & Christine Paulin