diff options
author | Stephane Glondu <steph@glondu.net> | 2012-01-12 16:02:20 +0100 |
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committer | Stephane Glondu <steph@glondu.net> | 2012-01-12 16:02:20 +0100 |
commit | 97fefe1fcca363a1317e066e7f4b99b9c1e9987b (patch) | |
tree | 97ec6b7d831cc5fb66328b0c63a11db1cbb2f158 /theories/Logic/ClassicalDescription.v | |
parent | 300293c119981054c95182a90c829058530a6b6f (diff) |
Imported Upstream version 8.4~betaupstream/8.4_beta
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}. |