From 7d220f8b61649646692983872626d6a8042446a9 Mon Sep 17 00:00:00 2001
From: letouzey <letouzey@85f007b7-540e-0410-9357-904b9bb8a0f7>
Date: Fri, 20 Mar 2009 01:22:58 +0000
Subject: Directory 'contrib' renamed into 'plugins', to end confusion with
 archive of user contribs

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@11996 85f007b7-540e-0410-9357-904b9bb8a0f7
---
 plugins/setoid_ring/Ring.v | 44 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 plugins/setoid_ring/Ring.v

(limited to 'plugins/setoid_ring/Ring.v')

diff --git a/plugins/setoid_ring/Ring.v b/plugins/setoid_ring/Ring.v
new file mode 100644
index 000000000..d01b16258
--- /dev/null
+++ b/plugins/setoid_ring/Ring.v
@@ -0,0 +1,44 @@
+(************************************************************************)
+(*  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        *)
+(************************************************************************)
+
+Require Import Bool.
+Require Export Ring_theory.
+Require Export Ring_base.
+Require Export InitialRing.
+Require Export Ring_tac.
+
+Lemma BoolTheory :
+  ring_theory false true xorb andb xorb (fun b:bool => b) (eq(A:=bool)).
+split; simpl in |- *.
+destruct x; reflexivity.
+destruct x; destruct y; reflexivity.
+destruct x; destruct y; destruct z; reflexivity.
+reflexivity.
+destruct x; destruct y; reflexivity.
+destruct x; destruct y; reflexivity.
+destruct x; destruct y; destruct z; reflexivity.
+reflexivity.
+destruct x; reflexivity.
+Qed.
+
+Definition bool_eq (b1 b2:bool) :=
+  if b1 then b2 else negb b2.
+
+Lemma bool_eq_ok : forall b1 b2, bool_eq b1 b2 = true -> b1 = b2.
+destruct b1; destruct b2; auto.
+Qed.
+
+Ltac bool_cst t :=
+  let t := eval hnf in t in
+  match t with
+    true => constr:true
+  | false => constr:false
+  | _ => constr:NotConstant
+  end.
+
+Add Ring bool_ring : BoolTheory (decidable bool_eq_ok, constants [bool_cst]).
-- 
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