From 9043add656177eeac1491a73d2f3ab92bec0013c Mon Sep 17 00:00:00 2001
From: Benjamin Barenblat <bbaren@debian.org>
Date: Sat, 29 Dec 2018 14:31:27 -0500
Subject: Imported Upstream version 8.8.2

---
 theories/Logic/PropExtensionality.v | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 theories/Logic/PropExtensionality.v

(limited to 'theories/Logic/PropExtensionality.v')

diff --git a/theories/Logic/PropExtensionality.v b/theories/Logic/PropExtensionality.v
new file mode 100644
index 00000000..80dd4e85
--- /dev/null
+++ b/theories/Logic/PropExtensionality.v
@@ -0,0 +1,24 @@
+(************************************************************************)
+(*         *   The Coq Proof Assistant / The Coq Development Team       *)
+(*  v      *   INRIA, CNRS and contributors - Copyright 1999-2018       *)
+(* <O___,, *       (see CREDITS file for the list of authors)           *)
+(*   \VV/  **************************************************************)
+(*    //   *    This file is distributed under the terms of the         *)
+(*         *     GNU Lesser General Public License Version 2.1          *)
+(*         *     (see LICENSE file for the text of the license)         *)
+(************************************************************************)
+
+(** This module states propositional extensionality and draws
+    consequences of it *)
+
+Axiom propositional_extensionality :
+  forall (P Q : Prop), (P <-> Q) -> P = Q.
+
+Require Import ClassicalFacts.
+
+Theorem proof_irrelevance : forall (P:Prop) (p1 p2:P), p1 = p2.
+Proof.
+  apply ext_prop_dep_proof_irrel_cic.
+  exact propositional_extensionality.
+Qed.
+
-- 
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