partial update in static_2

[helm.git] / matita / matita / contribs / lambdadelta / ground / arith / nat_pred_succ.ma

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 dafe179103c40e47e1826004af3b277d07961bd2..4a6e23b01846b0fd7b807b095b87add5b44d060f 100644 (file)
--- 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.
 * //