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

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diff --git a/plugins/micromega/Refl.v b/plugins/micromega/Refl.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        *)
+(************************************************************************)
+(*                                                                      *)
+(* Micromega: A reflexive tactic using the Positivstellensatz           *)
+(*                                                                      *)
+(*  Frédéric Besson (Irisa/Inria) 2006-2008                             *)
+(*                                                                      *)
+(************************************************************************)
+
+Require Import List.
+Require Setoid.
+
+Set Implicit Arguments.
+
+(* Refl of '->' '/\': basic properties *)
+
+Fixpoint make_impl (A : Type) (eval : A -> Prop) (l : list A) (goal : Prop) {struct l} : Prop :=
+  match l with
+    | nil => goal
+    | cons e l => (eval e) -> (make_impl eval l goal)
+  end.
+
+Theorem make_impl_true :
+  forall (A : Type) (eval : A -> Prop) (l : list A), make_impl eval l True.
+Proof.
+induction l as [| a l IH]; simpl.
+trivial.
+intro; apply IH.
+Qed.
+
+Fixpoint make_conj (A : Type) (eval : A -> Prop) (l : list A) {struct l} : Prop :=
+  match l with
+    | nil => True
+    | cons e nil => (eval e)
+    | cons e l2 => ((eval e) /\ (make_conj eval l2))
+  end.
+
+Theorem make_conj_cons : forall (A : Type) (eval : A -> Prop) (a : A) (l : list A),
+  make_conj eval (a :: l) <-> eval a /\ make_conj eval l.
+Proof.
+intros; destruct l; simpl; tauto.
+Qed.
+
+
+Lemma make_conj_impl : forall (A : Type) (eval : A -> Prop) (l : list A) (g : Prop),
+  (make_conj eval l -> g) <-> make_impl eval l g.
+Proof.
+  induction l.
+  simpl.
+  tauto.
+  simpl.
+  intros.
+  destruct l.
+  simpl.
+  tauto.
+  generalize (IHl g).
+  tauto.
+Qed.
+
+Lemma make_conj_in : forall (A : Type) (eval : A -> Prop) (l : list A),
+  make_conj eval l -> (forall p, In p l -> eval p).
+Proof.
+  induction l.
+  simpl.
+  tauto.
+  simpl.
+  intros.
+  destruct l.
+  simpl in H0.
+  destruct H0.
+  subst; auto.
+  tauto.
+  destruct H.
+  destruct H0.
+  subst;auto.
+  apply IHl; auto.
+Qed.
+
+
+
+Lemma make_conj_app : forall  A eval l1 l2, @make_conj A eval (l1 ++ l2) <-> @make_conj A eval l1 /\ @make_conj A eval l2.
+Proof.
+  induction l1.
+  simpl.
+  tauto.
+  intros.
+  change ((a::l1) ++ l2) with (a :: (l1 ++ l2)).
+  rewrite make_conj_cons.
+  rewrite IHl1.
+  rewrite make_conj_cons.
+  tauto.
+Qed.
+
+Lemma not_make_conj_cons : forall (A:Type) (t:A) a eval  (no_middle_eval : (eval t) \/ ~ (eval  t)),
+  ~ make_conj  eval (t ::a) -> ~  (eval t) \/ (~ make_conj  eval a).
+Proof.
+  intros.
+  simpl in H.
+  destruct a.
+  tauto.
+  tauto.
+Qed.
+
+Lemma not_make_conj_app : forall (A:Type) (t:list A) a eval
+  (no_middle_eval : forall d, eval d \/ ~ eval d) , 
+  ~ make_conj  eval (t ++ a) -> (~ make_conj  eval t) \/ (~ make_conj eval a).
+Proof.
+  induction t.
+  simpl.
+  tauto.
+  intros.
+  simpl ((a::t)++a0)in H.
+  destruct (@not_make_conj_cons _ _ _ _  (no_middle_eval a) H).
+  left ; red ; intros.
+  apply H0.
+  rewrite  make_conj_cons in H1.
+  tauto.
+  destruct (IHt _ _ no_middle_eval H0).
+  left ; red ; intros.
+  apply H1.
+  rewrite make_conj_cons in H2.
+  tauto.
+  right ; auto.
+Qed.