X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fmatita%2Fcontribs%2Fassembly%2Ffreescale%2Fextra.ma;h=207a5a267d386b67af511cedf815e1c242114261;hb=a8a93651c567a67149200636374df96c87508aa8;hp=f683ecf8fa42e271a7a252c04a3d0ce507ffcb7c;hpb=55e5bef77f163b29feeb9ad4e83376c5aa301297;p=helm.git

diff --git a/helm/software/matita/contribs/assembly/freescale/extra.ma b/helm/software/matita/contribs/assembly/freescale/extra.ma
index f683ecf8f..207a5a267 100644
--- 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;