anchor.diff:  Version 4.5 was demonstrated in June 1988 at the YoP Institute on Logical
   Foundations of Functional Programming organized by Gérard Huet at Austin, Texas.
   
  -Version 4.6 was started during summer 1988. Its main improvement was the
  +Version 4.6 was started during the summer of 1988. Its main improvement was the
   complete rehaul of the proof synthesis engine by Thierry Coquand, with
   a tree structure of goals.
   
  
positive.code: Mathematics_. Invited paper, EUROCAL85, April 1985, Linz, Austria. Springer Verlag
  LNCS 203, pp. 151-184.
  
  Christine Paulin joined the team at this point, for her DEA research internship.
  In her DEA memoir (August 1985) she presents developments for the _lambo_ function
  computing the minimal _m_ such that _f(m)_ is greater than _n_, for _f_ an increasing
  integer function, a challenge for constructive mathematics. She also encoded
  the majority voting algorithm of Boyer and Moore.
  
  Version 2
  
negative.code: In P. Martin-Löf and G. Mints, editors, Proceedings of Colog'88, volume 417,
  Lecture Notes in Computer Science. Springer-Verlag, 1990.
  
  This led to the Calculus of Inductive Constructions, logical formalism
  implemented in Versions 5 upward of the system, and documented in:
  C. Paulin-Mohring. _Inductive Definitions in the System Coq - Rules and
  Properties_. In M. Bezem and J.-F. Groote, editors, Proceedings of the conference
  