+++ /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/relevant_equations.ma".
-
-include "nat/times.ma".
-include "nat/minus.ma".
-
-theorem times_plus_l: \forall n,m,p:nat. (n+m)*p = n*p + m*p.
-intros.
-apply (trans_eq ? ? (p*(n+m))).
-apply sym_times.
-apply (trans_eq ? ? (p*n+p*m)).
-apply distr_times_plus.
-apply eq_f2.
-apply sym_times.
-apply sym_times.
-qed.
-
-theorem times_minus_l: \forall n,m,p:nat. (n-m)*p = n*p - m*p.
-intros.
-apply (trans_eq ? ? (p*(n-m))).
-apply sym_times.
-apply (trans_eq ? ? (p*n-p*m)).
-apply distr_times_minus.
-apply eq_f2.
-apply sym_times.
-apply sym_times.
-qed.
-
-theorem times_plus_plus: \forall n,m,p,q:nat. (n + m)*(p + q) =
-n*p + n*q + m*p + m*q.
-intros.
-apply (trans_eq nat ? ((n*(p+q) + m*(p+q)))).
-apply times_plus_l.
-rewrite > distr_times_plus.
-rewrite > distr_times_plus.
-rewrite < assoc_plus.reflexivity.
-qed.