X-Git-Url: http://matita.cs.unibo.it/gitweb/?p=helm.git;a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fground%2Farith%2Fnat_pred.ma;h=3d665506579765b2246ce3985a9458ed9154f49e;hp=4fcab387d0bd8d5248fef6c98e41d0abc2a78f9e;hb=68e028d053806177e218ee1a5f8778d3011bef83;hpb=ccf5878f2a2ec7f952f140e162391708a740517b

diff --git a/matita/matita/contribs/lambdadelta/ground/arith/nat_pred.ma b/matita/matita/contribs/lambdadelta/ground/arith/nat_pred.ma
index 4fcab387d..3d6655065 100644
--- a/matita/matita/contribs/lambdadelta/ground/arith/nat_pred.ma
+++ b/matita/matita/contribs/lambdadelta/ground/arith/nat_pred.ma
@@ -25,10 +25,11 @@ definition npred (m): nat ≝ match m with
 ].
 
 interpretation
-  "predecessor (non-negative integers"
+  "predecessor (non-negative integers)"
   'DownArrow m = (npred m).
 
 (* Basic rewrites ***********************************************************)
 
+(*** pred_O *)
 lemma npred_zero: 𝟎 = ↓𝟎.
 // qed.