...

diff --git a/helm/software/matita/library/nat/nat.ma b/helm/software/matita/library/nat/nat.ma
index c54b41c8d71e73262c949ea5043b6ddd2c4cc5d4..b098279e62e9ed3ecf1cf99a04e564faaf3bbf2c 100644 (file)
--- a/helm/software/matita/library/nat/nat.ma
+++ b/helm/software/matita/library/nat/nat.ma
@@ -19,6 +19,7 @@ inductive nat : Set \def
   | 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