X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fmatita%2Flibrary%2Fnat%2Ffactorial2.ma;h=6215d6657892ab39eb0233763885657f35796725;hb=3f5a0152427fd9a89e7239befd259d27b97aaef5;hp=594feb51f7ec365fe4ea568f9723c2e33d489c13;hpb=789339cc1451af401ae8c2f8adad137568d8aa1d;p=helm.git

diff --git a/helm/software/matita/library/nat/factorial2.ma b/helm/software/matita/library/nat/factorial2.ma
index 594feb51f..6215d6657 100644
--- a/helm/software/matita/library/nat/factorial2.ma
+++ b/helm/software/matita/library/nat/factorial2.ma
@@ -25,11 +25,6 @@ theorem exp_S: \forall n,m. exp m (S n) = m*exp m n.
 intros.reflexivity.
 qed.
 
-alias num (instance 0) = "natural number".
-lemma times_SSO: \forall n.2*(S n) = S(S(2*n)).
-intro.simplify.rewrite < plus_n_Sm.reflexivity.
-qed.
-
 theorem lt_O_to_fact1: \forall n.O<n \to
 fact (2*n) \le (exp 2 (pred (2*n)))*(fact n)*(fact n).
 intros.elim H