X-Git-Url: http://matita.cs.unibo.it/gitweb/?p=helm.git;a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fground%2Farith%2Fnat_pred_succ.ma;h=4a6e23b01846b0fd7b807b095b87add5b44d060f;hp=dafe179103c40e47e1826004af3b277d07961bd2;hb=8fe4dc148d50a0352313633bea61441bc817afbf;hpb=cab35e3d6c09d266c1372b5cc9a0045578bae79b

diff --git a/matita/matita/contribs/lambdadelta/ground/arith/nat_pred_succ.ma b/matita/matita/contribs/lambdadelta/ground/arith/nat_pred_succ.ma
index dafe17910..4a6e23b01 100644
--- a/matita/matita/contribs/lambdadelta/ground/arith/nat_pred_succ.ma
+++ b/matita/matita/contribs/lambdadelta/ground/arith/nat_pred_succ.ma
@@ -34,6 +34,10 @@ lemma pnpred_psucc (p): pnpred (psucc p) = nsucc (pnpred p).
 
 (* Constructions with nsucc *************************************************)
 
+lemma nsucc_pnpred (p):
+      ninj p = ↑(pnpred p).
+// qed.
+
 (*** pred_Sn pred_S *)
 lemma npred_succ (n): n = ↓↑n.
 * //