Some more fixes. Boring and stupid!

[helm.git] / helm / software / matita / contribs / assembly / freescale / extra.ma

diff --git a/helm/software/matita/contribs/assembly/freescale/extra.ma b/helm/software/matita/contribs/assembly/freescale/extra.ma
index f683ecf8fa42e271a7a252c04a3d0ce507ffcb7c..207a5a267d386b67af511cedf815e1c242114261 100644 (file)
--- a/helm/software/matita/contribs/assembly/freescale/extra.ma
+++ b/helm/software/matita/contribs/assembly/freescale/extra.ma
@@ -78,6 +78,27 @@ lemma xorbool_switch : ∀b1,b2.xor_bool b1 b2 = xor_bool b2 b1.
  reflexivity.
 qed.
 
+
+lemma orb_false_false :
+ ∀b1,b2:bool.((or_bool b1 b2) = false) → b1 = false.
+ intros 2;
+ elim b1 0;
+ elim b2;
+ simplify in H;
+ try destruct H;
+ reflexivity.
+qed.
+
+lemma orb_false_false_r :
+ ∀b1,b2:bool.((or_bool b1 b2) = false) → b2 = false.
+ intros 2;
+ elim b1 0;
+ elim b2;
+ simplify in H;
+ try destruct H;
+ reflexivity.
+qed.
+
 lemma eqbool_to_eq : ∀b1,b2:bool.(eq_bool b1 b2 = true) → (b1 = b2).
  unfold eq_bool;
  intros;