X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fmatita%2Flibrary%2FZ%2Fz.ma;h=8ce0047e169f6b6a8b014d4614877e6e9c2eb7c4;hb=8b55faddb06e3c4b0a13839210bb49170939b33e;hp=423399ff2c85449324be1f97ee243930182e0114;hpb=373b88228a8f9a6b4b4dcf781bc166865f89f43d;p=helm.git

diff --git a/helm/matita/library/Z/z.ma b/helm/matita/library/Z/z.ma
index 423399ff2..8ce0047e1 100644
--- a/helm/matita/library/Z/z.ma
+++ b/helm/matita/library/Z/z.ma
@@ -51,7 +51,7 @@ match z with
 theorem OZ_test_to_Prop :\forall z:Z.
 match OZ_test z with
 [true \Rightarrow z=OZ 
-|false \Rightarrow \lnot (z=OZ)].
+|false \Rightarrow z \neq OZ].
 intros.elim z.
 simplify.reflexivity.
 simplify.intros [H].
@@ -81,17 +81,17 @@ qed.
 variant inj_neg : \forall n,m:nat. neg n = neg m \to n = m
 \def injective_neg.
 
-theorem not_eq_OZ_pos: \forall n:nat. \lnot (OZ = (pos n)).
+theorem not_eq_OZ_pos: \forall n:nat. OZ \neq pos n.
 simplify.intros [n; H].
 discriminate H.
 qed.
 
-theorem not_eq_OZ_neg :\forall n:nat. \lnot (OZ = (neg n)).
+theorem not_eq_OZ_neg :\forall n:nat. OZ \neq neg n.
 simplify.intros [n; H].
 discriminate H.
 qed.
 
-theorem not_eq_pos_neg :\forall n,m:nat. \lnot ((pos n) = (neg m)).
+theorem not_eq_pos_neg :\forall n,m:nat. pos n \neq neg m.
 simplify.intros [n; m; H].
 discriminate H.
 qed.