internal quantification fixed

[helm.git] / helm / matita / library / datatypes / bool.ma

diff --git a/helm/matita/library/datatypes/bool.ma b/helm/matita/library/datatypes/bool.ma
index a4667da30249730b98bc4f39c522dd824a180019..f4aec8167476b0d88204a06d3d23aaa798a323ac 100644 (file)
--- a/helm/matita/library/datatypes/bool.ma
+++ b/helm/matita/library/datatypes/bool.ma
@@ -19,9 +19,20 @@ include "logic/equality.ma".
 inductive bool : Set \def 
   | true : bool
   | false : bool.
-  
+
+theorem bool_elim: \forall P:bool \to Prop. \forall b:bool.
+  (b = true \to P true)
+  \to (b = false \to P false)
+  \to P b.
+  intros 2 (P b).
+  elim b;
+  [ apply H; reflexivity
+  | apply H1; reflexivity
+  ]
+qed.
+
 theorem not_eq_true_false : true \neq false.
-simplify.intro.
+unfold Not.intro.
 change with 
 match true with
 [ true \Rightarrow False