X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fmatita%2Flibrary%2Fnat%2Fnat.ma;h=83b489f06eb08a6772e0d7abb00e315032604ad0;hb=b960f999600fc7e1037a08c700e50336c96db755;hp=9fce4df76a8b3dfbd7071582202ea648676d884b;hpb=2a31f145f58f7ba66b6445a9c8b31841054ef809;p=helm.git

diff --git a/helm/software/matita/library/nat/nat.ma b/helm/software/matita/library/nat/nat.ma
index 9fce4df76..83b489f06 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||                                                             *)
@@ -18,6 +18,12 @@ inductive nat : Set \def
   | O : nat
   | S : nat \to nat.
 
+interpretation "Natural numbers" 'N = nat.
+
+default "natural numbers" cic:/matita/nat/nat/nat.ind.
+
+alias num (instance 0) = "natural number".
+
 definition pred: nat \to nat \def
  \lambda n:nat. match n with
  [ O \Rightarrow  O