X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fmatita%2Flibrary%2FZ%2Fz.ma;h=9532ea95deb4d3ffb2a7c66b1665f58aa7a6c462;hb=871a376a3dc378a17ebdfc290618b8bcaed58ae1;hp=ea50a2cd9c3b70729df6c8c6bb4b16d661d80d41;hpb=55b82bd235d82ff7f0a40d980effe1efde1f5073;p=helm.git

diff --git a/helm/software/matita/library/Z/z.ma b/helm/software/matita/library/Z/z.ma
index ea50a2cd9..9532ea95d 100644
--- a/helm/software/matita/library/Z/z.ma
+++ b/helm/software/matita/library/Z/z.ma
@@ -38,8 +38,8 @@ definition abs \def
 \lambda z.
  match z with 
 [ OZ \Rightarrow O
-| (pos n) \Rightarrow n
-| (neg n) \Rightarrow n].
+| (pos n) \Rightarrow (S n)
+| (neg n) \Rightarrow (S n)].
 
 definition OZ_test \def
 \lambda z.
@@ -64,6 +64,7 @@ qed.
 theorem injective_pos: injective nat Z pos.
 unfold injective.
 intros.
+apply inj_S.
 change with (abs (pos x) = abs (pos y)).
 apply eq_f.assumption.
 qed.
@@ -74,6 +75,7 @@ variant inj_pos : \forall n,m:nat. pos n = pos m \to n = m
 theorem injective_neg: injective nat Z neg.
 unfold injective.
 intros.
+apply inj_S.
 change with (abs (neg x) = abs (neg y)).
 apply eq_f.assumption.
 qed.