X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fmatita%2Flibrary%2Fnat%2Fnat.ma;h=5e3e769ec11cf8778db2aa4d43986c5544b23d7e;hb=5c10d402b5de7233bc83d7f685b274832e383212;hp=b600072c61ba97cfa9e862251d04c566b3a0e765;hpb=55b82bd235d82ff7f0a40d980effe1efde1f5073;p=helm.git

diff --git a/helm/software/matita/library/nat/nat.ma b/helm/software/matita/library/nat/nat.ma
index b600072c6..5e3e769ec 100644
--- a/helm/software/matita/library/nat/nat.ma
+++ b/helm/software/matita/library/nat/nat.ma
@@ -1,5 +1,5 @@
 (**************************************************************************)
-(*       ___	                                                              *)
+(*       ___	                                                          *)
 (*      ||M||                                                             *)
 (*      ||A||       A project by Andrea Asperti                           *)
 (*      ||T||                                                             *)
@@ -12,21 +12,22 @@
 (*                                                                        *)
 (**************************************************************************)
 
-set "baseuri" "cic:/matita/nat/nat".
-
 include "higher_order_defs/functions.ma".
 
 inductive nat : Set \def
   | O : nat
   | S : nat \to nat.
 
+interpretation "Natural numbers" 'N = nat.
+alias num (instance 0) = "natural number".
+
 definition pred: nat \to nat \def
  \lambda n:nat. match n with
  [ O \Rightarrow  O
  | (S p) \Rightarrow p ].
 
 theorem pred_Sn : \forall n:nat.n=(pred (S n)).
- intros. reflexivity.
+ intros. simplify. reflexivity.
 qed.
 
 theorem injective_S : injective nat nat S.