--- /dev/null
+(**************************************************************************)
+(* __ *)
+(* ||M|| *)
+(* ||A|| A project by Andrea Asperti *)
+(* ||T|| *)
+(* ||I|| Developers: *)
+(* ||T|| A.Asperti, C.Sacerdoti Coen, *)
+(* ||A|| E.Tassi, S.Zacchiroli *)
+(* \ / *)
+(* \ / This file is distributed under the terms of the *)
+(* v GNU Lesser General Public License Version 2.1 *)
+(* *)
+(**************************************************************************)
+
+set "baseuri" "cic:/matita/nat/neper".
+
+include "nat/iteration2.ma".
+include "nat/div_and_mod_diseq.ma".
+
+theorem boh: \forall n,m.
+sigma_p n (\lambda i.true) (\lambda i.m/(exp (S(S O)) i)) \le
+((S(S O))*m*(exp (S(S O)) n) - (S(S O))*m)/(exp (S(S O)) n).
+intros.
+elim n
+ [apply le_O_n.
+ |rewrite > true_to_sigma_p_Sn
+ [apply (trans_le ? (m/(S(S O))\sup(n1)+((S(S O))*m*(S(S O))\sup(n1)-(S(S O))*m)/(S(S O))\sup(n1)))
+ [apply le_plus_r.assumption
+ |rewrite > assoc_times in ⊢ (? ? (? (? % ?) ?)).
+ rewrite < distr_times_minus.
+ change in ⊢ (? ? (? ? %)) with ((S(S O))*(exp (S(S O)) n1)).
+ rewrite > sym_times in ⊢ (? ? (? % ?)).
+ rewrite > sym_times in ⊢ (? ? (? ? %)).
+ rewrite < lt_to_lt_to_eq_div_div_times_times
+ [apply (trans_le ? ((m+((S(S O))*m*((S(S O)))\sup(n1)-(S(S O))*m))/((S(S O)))\sup(n1)))
+ [apply le_plus_div.
+ apply lt_O_exp.
+ apply lt_O_S
+ |change in ⊢ (? (? (? ? (? ? %)) ?) ?) with (m + (m +O)).
+ rewrite < plus_n_O.
+ rewrite < eq_minus_minus_minus_plus.
+ rewrite > sym_plus.
+ rewrite > sym_times in ⊢ (? (? (? (? (? (? % ?) ?) ?) ?) ?) ?).
+ rewrite > assoc_times.
+ rewrite < plus_minus_m_m
+ [apply le_n
+ |apply le_plus_to_minus_r.
+ rewrite > plus_n_O in ⊢ (? (? ? %) ?).
+ change in ⊢ (? % ?) with ((S(S O))*m).
+ rewrite > sym_times.
+ apply le_times_r.
+ rewrite > times_n_SO in ⊢ (? % ?).
+ apply le_times_r.
+ apply lt_O_exp.
+ apply lt_O_S
+ ]
+ ]
+ |apply lt_O_S
+ |apply lt_O_exp.
+ apply lt_O_S
+ ]
+ ]
+ |reflexivity
+ ]
+ ]
+qed.
+
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