(* *)
(**************************************************************************)
-set "baseuri" "cic:/matita/nat/binomial".
-
include "nat/iteration2.ma".
include "nat/factorial2.ma".
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.
+