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diff --git a/theories/Numbers/NatInt/NZTimes.v b/theories/Numbers/NatInt/NZTimes.v
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+++ b/theories/Numbers/NatInt/NZTimes.v
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+Require Import NZAxioms.
+Require Import NZPlus.
+
+Module NZTimesPropFunct (Import NZAxiomsMod : NZAxiomsSig).
+Module Export NZPlusPropMod := NZPlusPropFunct NZAxiomsMod.
+Open Local Scope NatIntScope.
+
+Theorem NZtimes_0_l : forall n : NZ, 0 * n == 0.
+Proof.
+NZinduct n.
+now rewrite NZtimes_0_r.
+intro. rewrite NZtimes_succ_r. now rewrite NZplus_0_r.
+Qed.
+
+Theorem NZtimes_succ_l : forall n m : NZ, (S n) * m == n * m + m.
+Proof.
+intros n m; NZinduct m.
+do 2 rewrite NZtimes_0_r; now rewrite NZplus_0_l.
+intro m. do 2 rewrite NZtimes_succ_r. do 2 rewrite NZplus_succ_r.
+rewrite NZsucc_inj_wd. rewrite <- (NZplus_assoc (n * m) n m).
+rewrite (NZplus_comm n m). rewrite NZplus_assoc.
+now rewrite NZplus_cancel_r.
+Qed.
+
+Theorem NZtimes_comm : forall n m : NZ, n * m == m * n.
+Proof.
+intros n m; NZinduct n.
+rewrite NZtimes_0_l; now rewrite NZtimes_0_r.
+intro. rewrite NZtimes_succ_l; rewrite NZtimes_succ_r. now rewrite NZplus_cancel_r.
+Qed.
+
+Theorem NZtimes_plus_distr_r : forall n m p : NZ, (n + m) * p == n * p + m * p.
+Proof.
+intros n m p; NZinduct n.
+rewrite NZtimes_0_l. now do 2 rewrite NZplus_0_l.
+intro n. rewrite NZplus_succ_l. do 2 rewrite NZtimes_succ_l.
+rewrite <- (NZplus_assoc (n * p) p (m * p)).
+rewrite (NZplus_comm p (m * p)). rewrite (NZplus_assoc (n * p) (m * p) p).
+now rewrite NZplus_cancel_r.
+Qed.
+
+Theorem NZtimes_plus_distr_l : forall n m p : NZ, n * (m + p) == n * m + n * p.
+Proof.
+intros n m p.
+rewrite (NZtimes_comm n (m + p)). rewrite (NZtimes_comm n m).
+rewrite (NZtimes_comm n p). apply NZtimes_plus_distr_r.
+Qed.
+
+Theorem NZtimes_assoc : forall n m p : NZ, n * (m * p) == (n * m) * p.
+Proof.
+intros n m p; NZinduct n.
+now do 3 rewrite NZtimes_0_l.
+intro n. do 2 rewrite NZtimes_succ_l. rewrite NZtimes_plus_distr_r.
+now rewrite NZplus_cancel_r.
+Qed.
+
+Theorem NZtimes_1_l : forall n : NZ, 1 * n == n.
+Proof.
+intro n. rewrite NZtimes_succ_l; rewrite NZtimes_0_l. now rewrite NZplus_0_l.
+Qed.
+
+Theorem NZtimes_1_r : forall n : NZ, n * 1 == n.
+Proof.
+intro n; rewrite NZtimes_comm; apply NZtimes_1_l.
+Qed.
+
+End NZTimesPropFunct.
+
+
+(*
+ Local Variables:
+ tags-file-name: "~/coq/trunk/theories/Numbers/TAGS"
+ End:
+*)