
 INRIA Futurs (Site not responding. Last check: 20070917) 
  In particular, the document should unify the existing consistency proofs, on one side of the calculus of constructions with strong and dependent elimination of inductive types, and on the other side with (floating) type universes, taking care of the guard conditions for inductive and coinductive recursion and of Prop to Set singleton elimination. 
  Coquand, Metamathematical Investigations of a Calculus of Constructions, Logic and Computer Science, 1990. 
  Luo, An Extended Calculus of Constructions, PhD thesis, 1990. 
 wwwfuturs.inria.fr /emplois/logical.en.html (334 words) 
