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Diffstat (limited to 'theories/Logic/ClassicalDescription.v')
| -rw-r--r-- | theories/Logic/ClassicalDescription.v | 10 |
1 files changed, 3 insertions, 7 deletions
diff --git a/theories/Logic/ClassicalDescription.v b/theories/Logic/ClassicalDescription.v index ad454a4d..d35ed138 100644 --- a/theories/Logic/ClassicalDescription.v +++ b/theories/Logic/ClassicalDescription.v @@ -1,13 +1,11 @@ (************************************************************************) (* v * The Coq Proof Assistant / The Coq Development Team *) -(* <O___,, * INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2011 *) +(* <O___,, * INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2010 *) (* \VV/ **************************************************************) (* // * This file is distributed under the terms of the *) (* * GNU Lesser General Public License Version 2.1 *) (************************************************************************) -(*i $Id: ClassicalDescription.v 14641 2011-11-06 11:59:10Z herbelin $ i*) - (** This file provides classical logic and definite description, which is equivalent to providing classical logic and Church's iota operator *) @@ -18,14 +16,12 @@ Set Implicit Arguments. -Require Export Classical. +Require Export Classical. (* Axiomatize classical reasoning *) +Require Export Description. (* Axiomatize constructive form of Church's iota *) Require Import ChoiceFacts. Notation Local inhabited A := A (only parsing). -Axiom constructive_definite_description : - forall (A : Type) (P : A->Prop), (exists! x : A, P x) -> { x : A | P x }. - (** The idea for the following proof comes from [ChicliPottierSimpson02] *) Theorem excluded_middle_informative : forall P:Prop, {P} + {~ P}. |