X-Git-Url: http://matita.cs.unibo.it/gitweb/?p=helm.git;a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fground%2Farith%2Fynat_succ.ma;h=9e4fb430cf71182640720323b20ffb472c656b25;hp=8f8fe4047d04d994e09b49e8b60f1bbfeb32ca1b;hb=6604a232815858a6c75dd25ac45abd68438077ff;hpb=888840f6b3a71d3d686b53b702d362ab90ab0038

diff --git a/matita/matita/contribs/lambdadelta/ground/arith/ynat_succ.ma b/matita/matita/contribs/lambdadelta/ground/arith/ynat_succ.ma
index 8f8fe4047..9e4fb430c 100644
--- a/matita/matita/contribs/lambdadelta/ground/arith/ynat_succ.ma
+++ b/matita/matita/contribs/lambdadelta/ground/arith/ynat_succ.ma
@@ -72,7 +72,7 @@ lemma eq_inv_ysucc_bi: injective … ysucc.
 #x1 @(ynat_split_nat_inf … x1) -x1
 [ #n1 #x2 <ysucc_inj #H
   elim (eq_inv_inj_ysucc … H) -H #n2 #H1 #H2 destruct
-  /3 width=1 by eq_inv_nsucc_bi, eq_f/
+  <(eq_inv_nsucc_bi … H2) -H2 //
 | #x2 #H <(eq_inv_inf_ysucc … H) -H //
 ]
 qed-.