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authorGravatar emakarov <emakarov@85f007b7-540e-0410-9357-904b9bb8a0f7>2007-07-13 17:52:22 +0000
committerGravatar emakarov <emakarov@85f007b7-540e-0410-9357-904b9bb8a0f7>2007-07-13 17:52:22 +0000
commite8f786b4ef55aae4fc40c46f1b73c185ee0e5819 (patch)
tree6c6f65c85a1476572ebca39c975e59c38d2e10d3 /theories/Numbers/NumPrelude.v
parent72cd18d711b3e9ea2ecb0d657187dc5febfbc8e3 (diff)
An update on axiomatization of number classes.
git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@10002 85f007b7-540e-0410-9357-904b9bb8a0f7
Diffstat (limited to 'theories/Numbers/NumPrelude.v')
-rw-r--r--theories/Numbers/NumPrelude.v9
1 files changed, 8 insertions, 1 deletions
diff --git a/theories/Numbers/NumPrelude.v b/theories/Numbers/NumPrelude.v
index 2fe547681..a23fb0bc0 100644
--- a/theories/Numbers/NumPrelude.v
+++ b/theories/Numbers/NumPrelude.v
@@ -18,7 +18,14 @@ Definition eq_bool := (@eq bool).
Inductive eq_true : bool -> Prop := is_eq_true : eq_true true.
Coercion eq_true : bool >-> Sortclass.
-Theorem neg_eq_true : forall x : bool, ~ x -> x = false.
+Theorem eq_true_unfold : forall b : bool, b <-> b = true.
+Proof.
+intro b; split; intro H.
+now inversion H.
+now rewrite H.
+Qed.
+
+Theorem eq_true_neg : forall x : bool, ~ x -> x = false.
Proof.
intros x H; destruct x; [elim (H is_eq_true) | reflexivity].
Qed.