X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fmatita%2Flibrary%2Fnat%2Fbinomial.ma;h=83ef0acbb99d54f43ec260f16dc60447966be230;hb=b771a37f83637be22d9b3f1254a6a0f15dc49612;hp=1a341032032b95c317863801601446727cbd983a;hpb=d74bdbdea0586eaa764c53a22e2c660d5367d0d5;p=helm.git

diff --git a/helm/software/matita/library/nat/binomial.ma b/helm/software/matita/library/nat/binomial.ma
index 1a3410320..83ef0acbb 100644
--- a/helm/software/matita/library/nat/binomial.ma
+++ b/helm/software/matita/library/nat/binomial.ma
@@ -12,8 +12,6 @@
 (*                                                                        *)
 (**************************************************************************)
 
-set "baseuri" "cic:/matita/nat/binomial".
-
 include "nat/iteration2.ma".
 include "nat/factorial2.ma".
 
@@ -248,4 +246,15 @@ apply eq_sigma_p;intros
    rewrite < times_n_SO.
    reflexivity
   ]
-qed.
\ No newline at end of file
+qed.
+
+theorem exp_Sn_SSO: \forall n. exp (S n) 2 = S((exp n 2) + 2*n).
+intros.simplify.
+rewrite < times_n_SO.
+rewrite < plus_n_O.
+rewrite < sym_times.simplify.
+rewrite < assoc_plus.
+rewrite < sym_plus.
+reflexivity.
+qed.
+