X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fmatita%2Flibrary%2FZ%2Fz.ma;h=31c3a7003bdffca309780ce3e38122712efe4368;hb=395bcb2796cb9edcdb792579341c2271a8d1adaf;hp=d8b829ec1da6e60da84bf89fe20c94e80dc72351;hpb=576a1f3f67dc0207a664a127fe482facbfa2a826;p=helm.git

diff --git a/helm/software/matita/library/Z/z.ma b/helm/software/matita/library/Z/z.ma
index d8b829ec1..31c3a7003 100644
--- a/helm/software/matita/library/Z/z.ma
+++ b/helm/software/matita/library/Z/z.ma
@@ -12,8 +12,6 @@
 (*                                                                        *)
 (**************************************************************************)
 
-set "baseuri" "cic:/matita/Z/z".
-
 include "datatypes/bool.ma".
 include "nat/nat.ma".
 
@@ -22,18 +20,25 @@ inductive Z : Set \def
 | pos : nat \to Z
 | neg : nat \to Z.
 
+interpretation "Integers" 'Z = Z.
+
 definition Z_of_nat \def
 \lambda n. match n with
 [ O \Rightarrow  OZ 
 | (S n)\Rightarrow  pos n].
 
-coercion cic:/matita/Z/z/Z_of_nat.con.
+coercion Z_of_nat.
 
 definition neg_Z_of_nat \def
 \lambda n. match n with
 [ O \Rightarrow  OZ 
 | (S n)\Rightarrow  neg n].
 
+lemma pos_n_eq_S_n : \forall n : nat.
+  (pos n) = (S n).
+intro.reflexivity. 
+qed.
+
 definition abs \def
 \lambda z.
  match z with 
@@ -117,7 +122,7 @@ elim x.
   (* goal: x=pos y=pos *)
     elim (decidable_eq_nat n n1:((n=n1) \lor ((n=n1) \to False))).
     left.apply eq_f.assumption.
-    right.unfold Not.intros (H_inj).apply H. destruct H_inj. assumption.
+    right.unfold Not.intros (H_inj).apply H. destruct H_inj. reflexivity.
   (* goal: x=pos y=neg *)
     right.unfold Not.intro.apply (not_eq_pos_neg n n1). assumption.
 (* goal: x=neg *)