X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fmatita%2Flibrary%2Fnat%2Ftimes.ma;h=2ae5ffd749b745783a2cf8c3eded7166cc4f8108;hb=4167cea65ca58897d1a3dbb81ff95de5074700cc;hp=70a4fd76ef5ab626a2d6a00d13fb075406c55f2a;hpb=fb94e5a71be508516514dfe50528ccfb3cd2da91;p=helm.git

diff --git a/helm/matita/library/nat/times.ma b/helm/matita/library/nat/times.ma
index 70a4fd76e..2ae5ffd74 100644
--- a/helm/matita/library/nat/times.ma
+++ b/helm/matita/library/nat/times.ma
@@ -52,7 +52,7 @@ reflexivity.
 qed.
 
 theorem symmetric_times : symmetric nat times. 
-simplify.
+unfold symmetric.
 intros.elim x.
 simplify.apply times_n_O.
 simplify.rewrite > H.apply times_n_Sm.
@@ -62,7 +62,7 @@ variant sym_times : \forall n,m:nat. n*m = m*n \def
 symmetric_times.
 
 theorem distributive_times_plus : distributive nat times plus.
-simplify.
+unfold distributive.
 intros.elim x.
 simplify.reflexivity.
 simplify.rewrite > H. rewrite > assoc_plus.rewrite > assoc_plus.
@@ -74,7 +74,7 @@ variant distr_times_plus: \forall n,m,p:nat. n*(m+p) = n*m + n*p
 \def distributive_times_plus.
 
 theorem associative_times: associative nat times.
-simplify.intros.
+unfold associative.intros.
 elim x.simplify.apply refl_eq.
 simplify.rewrite < sym_times.
 rewrite > distr_times_plus.