Révision de theories/Logic concernant les axiomes de descriptions.

Mise à jour du tableau des axiomes dans la FAQ.



git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@10170 85f007b7-540e-0410-9357-904b9bb8a0f7

1 files changed, 21 insertions, 0 deletions

diff --git a/theories/Logic/Description.v b/theories/Logic/Description.v
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+(************************************************************************)
+(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
+(* <O___,, * CNRS-Ecole Polytechnique-INRIA Futurs-Universite Paris Sud *)
+(*   \VV/  **************************************************************)
+(*    //   *      This file is distributed under the terms of the       *)
+(*         *       GNU Lesser General Public License Version 2.1        *)
+(************************************************************************)
+
+(*i $Id$ i*)
+
+(** This file provides a constructive form of definite description; it
+    allows to build functions from the proof of their existence in any
+    context; this is weaker than Church's iota operator *)
+
+Require Import ChoiceFacts.
+
+Set Implicit Arguments.
+
+Axiom constructive_definite_description :
+  forall (A : Type) (P : A->Prop), 
+    (exists! x, P x) -> { x : A | P x }.