X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fground%2Farith%2Fnat_plus.ma;fp=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fground%2Farith%2Fnat_plus.ma;h=19b8acdd00578858526b21b7899c5a4d611a1961;hb=873fb39bdd21aa14877bf5d50db26e3a050c6d43;hp=a9894fc6285e7aaf7ec746ddfebacb208b91885e;hpb=503500ff9a6d9cca363a42b5fe7f3f5de69239f9;p=helm.git

diff --git a/matita/matita/contribs/lambdadelta/ground/arith/nat_plus.ma b/matita/matita/contribs/lambdadelta/ground/arith/nat_plus.ma
index a9894fc62..19b8acdd0 100644
--- a/matita/matita/contribs/lambdadelta/ground/arith/nat_plus.ma
+++ b/matita/matita/contribs/lambdadelta/ground/arith/nat_plus.ma
@@ -43,7 +43,7 @@ qed.
 
 (*** iter_plus *)
 lemma niter_plus (A) (f) (n1) (n2):
-      f^n2 ∘ f^n1 ≐ f^{A}(n1+n2).
+      f^n2 ∘ f^n1 ⊜ f^{A}(n1+n2).
 #A #f #n1 #n2 @(nat_ind_succ … n2) -n2 //
 #n2 #IH <nplus_succ_dx
 @exteq_repl