X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fground%2Farith%2Fnat_minus_plus.ma;h=97c24dbd470ae51b1eb17bb778a677f5df40dfa8;hb=d85eac4e29291d854469e626381654181b0c7e87;hp=e910fdaa0c94802be4767ba40f7e13a349951a46;hpb=2815c74c03f38089d0e27aba00e2280223b0f76f;p=helm.git

diff --git a/matita/matita/contribs/lambdadelta/ground/arith/nat_minus_plus.ma b/matita/matita/contribs/lambdadelta/ground/arith/nat_minus_plus.ma
index e910fdaa0..97c24dbd4 100644
--- a/matita/matita/contribs/lambdadelta/ground/arith/nat_minus_plus.ma
+++ b/matita/matita/contribs/lambdadelta/ground/arith/nat_minus_plus.ma
@@ -38,7 +38,7 @@ qed.
 
 (*** minus_plus_plus_l *)
 lemma nminus_plus_dx_bi (m) (n) (o): m - n = (m + o) - (n + o).
-#m #n #o <nminus_plus_assoc <nminus_comm //
+#m #n #o <nminus_plus_assoc <nminus_comm_21 //
 qed.
 
 (* Helper constructions with nplus ******************************************)