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-rw-r--r--Makefile.common1
-rw-r--r--theories/Numbers/Integer/Abstract/ZBase.v9
-rw-r--r--theories/Numbers/Integer/Abstract/ZLt.v28
-rw-r--r--theories/Numbers/Integer/Abstract/ZPlusOrder.v21
-rw-r--r--theories/Numbers/Integer/Abstract/ZTimesOrder.v145
-rw-r--r--theories/Numbers/NatInt/NZOrder.v10
-rw-r--r--theories/Numbers/NatInt/NZPlusOrder.v166
-rw-r--r--theories/Numbers/NatInt/NZTimesOrder.v225
-rw-r--r--theories/Numbers/Natural/Abstract/NBase.v9
-rw-r--r--theories/Numbers/Natural/Abstract/NOrder.v6
-rw-r--r--theories/Numbers/Natural/Abstract/NTimesOrder.v24
11 files changed, 430 insertions, 214 deletions
diff --git a/Makefile.common b/Makefile.common
index 474296232..22466fe10 100644
--- a/Makefile.common
+++ b/Makefile.common
@@ -656,6 +656,7 @@ NATINTVO:=\
$(NATINTDIR)/NZPlus.vo\
$(NATINTDIR)/NZTimes.vo\
$(NATINTDIR)/NZOrder.vo\
+ $(NATINTDIR)/NZPlusOrder.vo\
$(NATINTDIR)/NZTimesOrder.vo
NATURALDIR:=$(NUMBERSDIR)/Natural
diff --git a/theories/Numbers/Integer/Abstract/ZBase.v b/theories/Numbers/Integer/Abstract/ZBase.v
index db5bc99f9..0813a3caa 100644
--- a/theories/Numbers/Integer/Abstract/ZBase.v
+++ b/theories/Numbers/Integer/Abstract/ZBase.v
@@ -33,6 +33,15 @@ Proof NZpred_wd.
Theorem Zpred_succ : forall n : Z, P (S n) == n.
Proof NZpred_succ.
+Theorem Zeq_refl : forall n : Z, n == n.
+Proof (proj1 NZeq_equiv).
+
+Theorem Zeq_symm : forall n m : Z, n == m -> m == n.
+Proof (proj2 (proj2 NZeq_equiv)).
+
+Theorem Zeq_trans : forall n m p : Z, n == m -> m == p -> n == p.
+Proof (proj1 (proj2 NZeq_equiv)).
+
Theorem Zneq_symm : forall n m : Z, n ~= m -> m ~= n.
Proof NZneq_symm.
diff --git a/theories/Numbers/Integer/Abstract/ZLt.v b/theories/Numbers/Integer/Abstract/ZLt.v
index a81b3a419..27cbe085e 100644
--- a/theories/Numbers/Integer/Abstract/ZLt.v
+++ b/theories/Numbers/Integer/Abstract/ZLt.v
@@ -75,6 +75,12 @@ Proof NZlt_succ_diag_r.
Theorem Zle_succ_diag_r : forall n : Z, n <= S n.
Proof NZle_succ_diag_r.
+Theorem Zlt_0_1 : 0 < 1.
+Proof NZlt_0_1.
+
+Theorem Zle_0_1 : 0 <= 1.
+Proof NZle_0_1.
+
Theorem Zlt_lt_succ_r : forall n m : Z, n < m -> n < S m.
Proof NZlt_lt_succ_r.
@@ -150,6 +156,28 @@ Proof NZlt_ge_cases.
Theorem Zle_ge_cases : forall n m : Z, n <= m \/ n >= m.
Proof NZle_ge_cases.
+(** Instances of the previous theorems for m == 0 *)
+
+Theorem Zneg_pos_cases : forall n : Z, n ~= 0 <-> n < 0 \/ n > 0.
+Proof.
+intro; apply Zlt_gt_cases.
+Qed.
+
+Theorem Znonpos_pos_cases : forall n : Z, n <= 0 \/ n > 0.
+Proof.
+intro; apply Zle_gt_cases.
+Qed.
+
+Theorem Zneg_nonneg_cases : forall n : Z, n < 0 \/ n >= 0.
+Proof.
+intro; apply Zlt_ge_cases.
+Qed.
+
+Theorem Znonpos_nonneg_cases : forall n : Z, n <= 0 \/ n >= 0.
+Proof.
+intro; apply Zle_ge_cases.
+Qed.
+
Theorem Zle_ngt : forall n m : Z, n <= m <-> ~ n > m.
Proof NZle_ngt.
diff --git a/theories/Numbers/Integer/Abstract/ZPlusOrder.v b/theories/Numbers/Integer/Abstract/ZPlusOrder.v
index ce79055a7..c6d0efe45 100644
--- a/theories/Numbers/Integer/Abstract/ZPlusOrder.v
+++ b/theories/Numbers/Integer/Abstract/ZPlusOrder.v
@@ -89,6 +89,27 @@ Proof NZplus_nonneg_cases.
(** Theorems that are either not valid on N or have different proofs on N and Z *)
+Theorem Zplus_neg_neg : forall n m : Z, n < 0 -> m < 0 -> n + m < 0.
+Proof.
+intros n m H1 H2. rewrite <- (Zplus_0_l 0). now apply Zplus_lt_mono.
+Qed.
+
+Theorem Zplus_neg_nonpos : forall n m : Z, n < 0 -> m <= 0 -> n + m < 0.
+Proof.
+intros n m H1 H2. rewrite <- (Zplus_0_l 0). now apply Zplus_lt_le_mono.
+Qed.
+
+Theorem Zplus_nonpos_neg : forall n m : Z, n <= 0 -> m < 0 -> n + m < 0.
+Proof.
+intros n m H1 H2. rewrite <- (Zplus_0_l 0). now apply Zplus_le_lt_mono.
+Qed.
+
+Theorem Zplus_nonpos_nonpos : forall n m : Z, n <= 0 -> m <= 0 -> n + m <= 0.
+Proof.
+intros n m H1 H2. rewrite <- (Zplus_0_l 0). now apply Zplus_le_mono.
+Qed.
+
+
(** Minus and order *)
Theorem Zlt_lt_minus : forall n m : Z, n < m <-> 0 < m - n.
diff --git a/theories/Numbers/Integer/Abstract/ZTimesOrder.v b/theories/Numbers/Integer/Abstract/ZTimesOrder.v
index 287fdb7f1..a2360dd72 100644
--- a/theories/Numbers/Integer/Abstract/ZTimesOrder.v
+++ b/theories/Numbers/Integer/Abstract/ZTimesOrder.v
@@ -64,37 +64,66 @@ Proof NZtimes_le_mono_neg_l.
Theorem Ztimes_le_mono_neg_r : forall n m p : Z, p < 0 -> (n <= m <-> m * p <= n * p).
Proof NZtimes_le_mono_neg_r.
-Theorem Ztimes_lt_mono :
+Theorem Ztimes_lt_mono_nonneg :
forall n m p q : Z, 0 <= n -> n < m -> 0 <= p -> p < q -> n * p < m * q.
-Proof NZtimes_lt_mono.
+Proof NZtimes_lt_mono_nonneg.
-Theorem Ztimes_le_mono :
+Theorem Ztimes_lt_mono_nonpos :
+ forall n m p q : Z, m <= 0 -> n < m -> q <= 0 -> p < q -> m * q < n * p.
+Proof.
+intros n m p q H1 H2 H3 H4.
+apply Zle_lt_trans with (m * p).
+apply Ztimes_le_mono_nonpos_l; [assumption | now apply Zlt_le_incl].
+apply -> Ztimes_lt_mono_neg_r; [assumption | now apply Zlt_le_trans with q].
+Qed.
+
+Theorem Ztimes_le_mono_nonneg :
forall n m p q : Z, 0 <= n -> n <= m -> 0 <= p -> p <= q -> n * p <= m * q.
-Proof NZtimes_le_mono.
+Proof NZtimes_le_mono_nonneg.
+
+Theorem Ztimes_le_mono_nonpos :
+ forall n m p q : Z, m <= 0 -> n <= m -> q <= 0 -> p <= q -> m * q <= n * p.
+Proof.
+intros n m p q H1 H2 H3 H4.
+apply Zle_trans with (m * p).
+now apply Ztimes_le_mono_nonpos_l.
+apply Ztimes_le_mono_nonpos_r; [now apply Zle_trans with q | assumption].
+Qed.
Theorem Ztimes_pos_pos : forall n m : Z, 0 < n -> 0 < m -> 0 < n * m.
Proof NZtimes_pos_pos.
-Theorem Ztimes_nonneg_nonneg : forall n m : Z, 0 <= n -> 0 <= m -> 0 <= n * m.
-Proof NZtimes_nonneg_nonneg.
-
Theorem Ztimes_neg_neg : forall n m : Z, n < 0 -> m < 0 -> 0 < n * m.
Proof NZtimes_neg_neg.
-Theorem Ztimes_nonpos_nonpos : forall n m : Z, n <= 0 -> m <= 0 -> 0 <= n * m.
-Proof NZtimes_nonpos_nonpos.
-
Theorem Ztimes_pos_neg : forall n m : Z, 0 < n -> m < 0 -> n * m < 0.
Proof NZtimes_pos_neg.
-Theorem Ztimes_nonneg_nonpos : forall n m : Z, 0 <= n -> m <= 0 -> n * m <= 0.
-Proof NZtimes_nonneg_nonpos.
-
Theorem Ztimes_neg_pos : forall n m : Z, n < 0 -> 0 < m -> n * m < 0.
Proof NZtimes_neg_pos.
+Theorem Ztimes_nonneg_nonneg : forall n m : Z, 0 <= n -> 0 <= m -> 0 <= n * m.
+Proof.
+intros n m H1 H2.
+rewrite <- (Ztimes_0_l m). now apply Ztimes_le_mono_nonneg_r.
+Qed.
+
+Theorem Ztimes_nonpos_nonpos : forall n m : Z, n <= 0 -> m <= 0 -> 0 <= n * m.
+Proof.
+intros n m H1 H2.
+rewrite <- (Ztimes_0_l m). now apply Ztimes_le_mono_nonpos_r.
+Qed.
+
+Theorem Ztimes_nonneg_nonpos : forall n m : Z, 0 <= n -> m <= 0 -> n * m <= 0.
+Proof.
+intros n m H1 H2.
+rewrite <- (Ztimes_0_l m). now apply Ztimes_le_mono_nonpos_r.
+Qed.
+
Theorem Ztimes_nonpos_nonneg : forall n m : Z, n <= 0 -> 0 <= m -> n * m <= 0.
-Proof NZtimes_nonpos_nonneg.
+Proof.
+intros; rewrite Ztimes_comm; now apply Ztimes_nonneg_nonpos.
+Qed.
Theorem Zlt_1_times_pos : forall n m : Z, 1 < n -> 0 < m -> 1 < n * m.
Proof NZlt_1_times_pos.
@@ -111,12 +140,90 @@ Proof NZeq_times_0_l.
Theorem Zeq_times_0_r : forall n m : Z, n * m == 0 -> n ~= 0 -> m == 0.
Proof NZeq_times_0_r.
-Theorem Ztimes_pos : forall n m : Z, 0 < n * m <-> (0 < n /\ 0 < m) \/ (m < 0 /\ n < 0).
-Proof NZtimes_pos.
+Theorem Zlt_0_times : forall n m : Z, 0 < n * m <-> 0 < n /\ 0 < m \/ m < 0 /\ n < 0.
+Proof NZlt_0_times.
+
+Notation Ztimes_pos := Zlt_0_times (only parsing).
-Theorem Ztimes_neg :
- forall n m : Z, n * m < 0 <-> (n < 0 /\ m > 0) \/ (n > 0 /\ m < 0).
-Proof NZtimes_neg.
+Theorem Zlt_times_0 :
+ forall n m : Z, n * m < 0 <-> n < 0 /\ m > 0 \/ n > 0 /\ m < 0.
+Proof.
+intros n m; split; [intro H | intros [[H1 H2] | [H1 H2]]].
+destruct (Zlt_trichotomy n 0) as [H1 | [H1 | H1]];
+[| rewrite H1 in H; rewrite Ztimes_0_l in H; false_hyp H Zlt_irrefl |];
+(destruct (Zlt_trichotomy m 0) as [H2 | [H2 | H2]];
+[| rewrite H2 in H; rewrite Ztimes_0_r in H; false_hyp H Zlt_irrefl |]);
+try (left; now split); try (right; now split).
+assert (H3 : n * m > 0) by now apply Ztimes_neg_neg.
+elimtype False; now apply (Zlt_asymm (n * m) 0).
+assert (H3 : n * m > 0) by now apply Ztimes_pos_pos.
+elimtype False; now apply (Zlt_asymm (n * m) 0).
+now apply Ztimes_neg_pos. now apply Ztimes_pos_neg.
+Qed.
+
+Notation Ztimes_neg := Zlt_times_0 (only parsing).
+
+Theorem Zle_0_times :
+ forall n m : Z, 0 <= n * m -> 0 <= n /\ 0 <= m \/ n <= 0 /\ m <= 0.
+Proof.
+assert (R : forall n : Z, 0 == n <-> n == 0) by (intros; split; apply Zeq_symm).
+intros n m. repeat rewrite Zlt_eq_cases. repeat rewrite R.
+rewrite Zlt_0_times, Zeq_times_0.
+pose proof (Zlt_trichotomy n 0); pose proof (Zlt_trichotomy m 0). tauto.
+Qed.
+
+Notation Ztimes_nonneg := Zle_0_times (only parsing).
+
+Theorem Zle_times_0 :
+ forall n m : Z, n * m <= 0 -> 0 <= n /\ m <= 0 \/ n <= 0 /\ 0 <= m.
+Proof.
+assert (R : forall n : Z, 0 == n <-> n == 0) by (intros; split; apply Zeq_symm).
+intros n m. repeat rewrite Zlt_eq_cases. repeat rewrite R.
+rewrite Zlt_times_0, Zeq_times_0.
+pose proof (Zlt_trichotomy n 0); pose proof (Zlt_trichotomy m 0). tauto.
+Qed.
+
+Notation Ztimes_nonpos := Zle_times_0 (only parsing).
+
+Theorem Zsquare_lt_mono_nonneg : forall n m : Z, 0 <= n -> n < m -> n * n < m * m.
+Proof NZsquare_lt_mono_nonneg.
+
+Theorem Zsquare_lt_mono_nonpos : forall n m : Z, n <= 0 -> m < n -> n * n < m * m.
+Proof.
+intros n m H1 H2. now apply Ztimes_lt_mono_nonpos.
+Qed.
+
+Theorem Zsquare_le_mono_nonneg : forall n m : Z, 0 <= n -> n <= m -> n * n <= m * m.
+Proof NZsquare_le_mono_nonneg.
+
+Theorem Zsquare_le_mono_nonpos : forall n m : Z, n <= 0 -> m <= n -> n * n <= m * m.
+Proof.
+intros n m H1 H2. now apply Ztimes_le_mono_nonpos.
+Qed.
+
+Theorem Zsquare_lt_simpl_nonneg : forall n m : Z, 0 <= m -> n * n < m * m -> n < m.
+Proof NZsquare_lt_simpl_nonneg.
+
+Theorem Zsquare_le_simpl_nonneg : forall n m : Z, 0 <= m -> n * n <= m * m -> n <= m.
+Proof NZsquare_le_simpl_nonneg.
+
+Theorem Zsquare_lt_simpl_nonpos : forall n m : Z, m <= 0 -> n * n < m * m -> m < n.
+Proof.
+intros n m H1 H2. destruct (Zle_gt_cases n 0).
+destruct (NZlt_ge_cases m n).
+assumption. assert (F : m * m <= n * n) by now apply Zsquare_le_mono_nonpos.
+apply -> NZle_ngt in F. false_hyp H2 F.
+now apply Zle_lt_trans with 0.
+Qed.
+
+Theorem Zsquare_le_simpl_nonpos : forall n m : NZ, m <= 0 -> n * n <= m * m -> m <= n.
+Proof.
+intros n m H1 H2. destruct (NZle_gt_cases n 0).
+destruct (NZle_gt_cases m n).
+assumption. assert (F : m * m < n * n) by now apply Zsquare_lt_mono_nonpos.
+apply -> NZlt_nge in F. false_hyp H2 F.
+apply Zlt_le_incl; now apply NZle_lt_trans with 0.
+Qed.
Theorem Ztimes_2_mono_l : forall n m : Z, n < m -> 1 + (1 + 1) * n < (1 + 1) * m.
Proof NZtimes_2_mono_l.
diff --git a/theories/Numbers/NatInt/NZOrder.v b/theories/Numbers/NatInt/NZOrder.v
index df2f224f4..95df8e747 100644
--- a/theories/Numbers/NatInt/NZOrder.v
+++ b/theories/Numbers/NatInt/NZOrder.v
@@ -82,6 +82,16 @@ Proof.
intro; apply NZlt_le_incl; apply NZlt_succ_diag_r.
Qed.
+Theorem NZlt_0_1 : 0 < 1.
+Proof.
+apply NZlt_succ_diag_r.
+Qed.
+
+Theorem NZle_0_1 : 0 <= 1.
+Proof.
+apply NZle_succ_diag_r.
+Qed.
+
Theorem NZlt_lt_succ_r : forall n m : NZ, n < m -> n < S m.
Proof.
intros. rewrite NZlt_succ_r. now apply NZlt_le_incl.
diff --git a/theories/Numbers/NatInt/NZPlusOrder.v b/theories/Numbers/NatInt/NZPlusOrder.v
new file mode 100644
index 000000000..9f1ba0f84
--- /dev/null
+++ b/theories/Numbers/NatInt/NZPlusOrder.v
@@ -0,0 +1,166 @@
+(************************************************************************)
+(* v * The Coq Proof Assistant / The Coq Development Team *)
+(* <O___,, * CNRS-Ecole Polytechnique-INRIA Futurs-Universite Paris Sud *)
+(* \VV/ **************************************************************)
+(* // * This file is distributed under the terms of the *)
+(* * GNU Lesser General Public License Version 2.1 *)
+(************************************************************************)
+(* Evgeny Makarov, INRIA, 2007 *)
+(************************************************************************)
+
+(*i i*)
+
+Require Import NZAxioms.
+Require Import NZOrder.
+
+Module NZPlusOrderPropFunct (Import NZOrdAxiomsMod : NZOrdAxiomsSig).
+Module Export NZOrderPropMod := NZOrderPropFunct NZOrdAxiomsMod.
+Open Local Scope NatIntScope.
+
+Theorem NZplus_lt_mono_l : forall n m p : NZ, n < m <-> p + n < p + m.
+Proof.
+intros n m p; NZinduct p.
+now do 2 rewrite NZplus_0_l.
+intro p. do 2 rewrite NZplus_succ_l. now rewrite <- NZsucc_lt_mono.
+Qed.
+
+Theorem NZplus_lt_mono_r : forall n m p : NZ, n < m <-> n + p < m + p.
+Proof.
+intros n m p.
+rewrite (NZplus_comm n p); rewrite (NZplus_comm m p); apply NZplus_lt_mono_l.
+Qed.
+
+Theorem NZplus_lt_mono : forall n m p q : NZ, n < m -> p < q -> n + p < m + q.
+Proof.
+intros n m p q H1 H2.
+apply NZlt_trans with (m + p);
+[now apply -> NZplus_lt_mono_r | now apply -> NZplus_lt_mono_l].
+Qed.
+
+Theorem NZplus_le_mono_l : forall n m p : NZ, n <= m <-> p + n <= p + m.
+Proof.
+intros n m p; NZinduct p.
+now do 2 rewrite NZplus_0_l.
+intro p. do 2 rewrite NZplus_succ_l. now rewrite <- NZsucc_le_mono.
+Qed.
+
+Theorem NZplus_le_mono_r : forall n m p : NZ, n <= m <-> n + p <= m + p.
+Proof.
+intros n m p.
+rewrite (NZplus_comm n p); rewrite (NZplus_comm m p); apply NZplus_le_mono_l.
+Qed.
+
+Theorem NZplus_le_mono : forall n m p q : NZ, n <= m -> p <= q -> n + p <= m + q.
+Proof.
+intros n m p q H1 H2.
+apply NZle_trans with (m + p);
+[now apply -> NZplus_le_mono_r | now apply -> NZplus_le_mono_l].
+Qed.
+
+Theorem NZplus_lt_le_mono : forall n m p q : NZ, n < m -> p <= q -> n + p < m + q.
+Proof.
+intros n m p q H1 H2.
+apply NZlt_le_trans with (m + p);
+[now apply -> NZplus_lt_mono_r | now apply -> NZplus_le_mono_l].
+Qed.
+
+Theorem NZplus_le_lt_mono : forall n m p q : NZ, n <= m -> p < q -> n + p < m + q.
+Proof.
+intros n m p q H1 H2.
+apply NZle_lt_trans with (m + p);
+[now apply -> NZplus_le_mono_r | now apply -> NZplus_lt_mono_l].
+Qed.
+
+Theorem NZplus_pos_pos : forall n m : NZ, 0 < n -> 0 < m -> 0 < n + m.
+Proof.
+intros n m H1 H2. rewrite <- (NZplus_0_l 0). now apply NZplus_lt_mono.
+Qed.
+
+Theorem NZplus_pos_nonneg : forall n m : NZ, 0 < n -> 0 <= m -> 0 < n + m.
+Proof.
+intros n m H1 H2. rewrite <- (NZplus_0_l 0). now apply NZplus_lt_le_mono.
+Qed.
+
+Theorem NZplus_nonneg_pos : forall n m : NZ, 0 <= n -> 0 < m -> 0 < n + m.
+Proof.
+intros n m H1 H2. rewrite <- (NZplus_0_l 0). now apply NZplus_le_lt_mono.
+Qed.
+
+Theorem NZplus_nonneg_nonneg : forall n m : NZ, 0 <= n -> 0 <= m -> 0 <= n + m.
+Proof.
+intros n m H1 H2. rewrite <- (NZplus_0_l 0). now apply NZplus_le_mono.
+Qed.
+
+Theorem NZlt_plus_pos_l : forall n m : NZ, 0 < n -> m < n + m.
+Proof.
+intros n m H. apply -> (NZplus_lt_mono_r 0 n m) in H.
+now rewrite NZplus_0_l in H.
+Qed.
+
+Theorem NZlt_plus_pos_r : forall n m : NZ, 0 < n -> m < m + n.
+Proof.
+intros; rewrite NZplus_comm; now apply NZlt_plus_pos_l.
+Qed.
+
+Theorem NZle_lt_plus_lt : forall n m p q : NZ, n <= m -> p + m < q + n -> p < q.
+Proof.
+intros n m p q H1 H2. destruct (NZle_gt_cases q p); [| assumption].
+pose proof (NZplus_le_mono q p n m H H1) as H3. apply <- NZnle_gt in H2.
+false_hyp H3 H2.
+Qed.
+
+Theorem NZlt_le_plus_lt : forall n m p q : NZ, n < m -> p + m <= q + n -> p < q.
+Proof.
+intros n m p q H1 H2. destruct (NZle_gt_cases q p); [| assumption].
+pose proof (NZplus_le_lt_mono q p n m H H1) as H3. apply <- NZnle_gt in H3.
+false_hyp H2 H3.
+Qed.
+
+Theorem NZle_le_plus_le : forall n m p q : NZ, n <= m -> p + m <= q + n -> p <= q.
+Proof.
+intros n m p q H1 H2. destruct (NZle_gt_cases p q); [assumption |].
+pose proof (NZplus_lt_le_mono q p n m H H1) as H3. apply <- NZnle_gt in H3.
+false_hyp H2 H3.
+Qed.
+
+Theorem NZplus_lt_cases : forall n m p q : NZ, n + m < p + q -> n < p \/ m < q.
+Proof.
+intros n m p q H;
+destruct (NZle_gt_cases p n) as [H1 | H1].
+destruct (NZle_gt_cases q m) as [H2 | H2].
+pose proof (NZplus_le_mono p n q m H1 H2) as H3. apply -> NZle_ngt in H3.
+false_hyp H H3.
+now right. now left.
+Qed.
+
+Theorem NZplus_le_cases : forall n m p q : NZ, n + m <= p + q -> n <= p \/ m <= q.
+Proof.
+intros n m p q H.
+destruct (NZle_gt_cases n p) as [H1 | H1]. now left.
+destruct (NZle_gt_cases m q) as [H2 | H2]. now right.
+assert (H3 : p + q < n + m) by now apply NZplus_lt_mono.
+apply -> NZle_ngt in H. false_hyp H3 H.
+Qed.
+
+Theorem NZplus_neg_cases : forall n m : NZ, n + m < 0 -> n < 0 \/ m < 0.
+Proof.
+intros n m H; apply NZplus_lt_cases; now rewrite NZplus_0_l.
+Qed.
+
+Theorem NZplus_pos_cases : forall n m : NZ, 0 < n + m -> 0 < n \/ 0 < m.
+Proof.
+intros n m H; apply NZplus_lt_cases; now rewrite NZplus_0_l.
+Qed.
+
+Theorem NZplus_nonpos_cases : forall n m : NZ, n + m <= 0 -> n <= 0 \/ m <= 0.
+Proof.
+intros n m H; apply NZplus_le_cases; now rewrite NZplus_0_l.
+Qed.
+
+Theorem NZplus_nonneg_cases : forall n m : NZ, 0 <= n + m -> 0 <= n \/ 0 <= m.
+Proof.
+intros n m H; apply NZplus_le_cases; now rewrite NZplus_0_l.
+Qed.
+
+End NZPlusOrderPropFunct.
+
diff --git a/theories/Numbers/NatInt/NZTimesOrder.v b/theories/Numbers/NatInt/NZTimesOrder.v
index 4b4516069..aac823dc4 100644
--- a/theories/Numbers/NatInt/NZTimesOrder.v
+++ b/theories/Numbers/NatInt/NZTimesOrder.v
@@ -11,161 +11,12 @@
(*i i*)
Require Import NZAxioms.
-Require Import NZOrder.
+Require Import NZPlusOrder.
Module NZTimesOrderPropFunct (Import NZOrdAxiomsMod : NZOrdAxiomsSig).
-Module Export NZOrderPropMod := NZOrderPropFunct NZOrdAxiomsMod.
+Module Export NZPlusOrderPropMod := NZPlusOrderPropFunct NZOrdAxiomsMod.
Open Local Scope NatIntScope.
-(** Addition and order *)
-
-Theorem NZplus_lt_mono_l : forall n m p : NZ, n < m <-> p + n < p + m.
-Proof.
-intros n m p; NZinduct p.
-now do 2 rewrite NZplus_0_l.
-intro p. do 2 rewrite NZplus_succ_l. now rewrite <- NZsucc_lt_mono.
-Qed.
-
-Theorem NZplus_lt_mono_r : forall n m p : NZ, n < m <-> n + p < m + p.
-Proof.
-intros n m p.
-rewrite (NZplus_comm n p); rewrite (NZplus_comm m p); apply NZplus_lt_mono_l.
-Qed.
-
-Theorem NZplus_lt_mono : forall n m p q : NZ, n < m -> p < q -> n + p < m + q.
-Proof.
-intros n m p q H1 H2.
-apply NZlt_trans with (m + p);
-[now apply -> NZplus_lt_mono_r | now apply -> NZplus_lt_mono_l].
-Qed.
-
-Theorem NZplus_le_mono_l : forall n m p : NZ, n <= m <-> p + n <= p + m.
-Proof.
-intros n m p; NZinduct p.
-now do 2 rewrite NZplus_0_l.
-intro p. do 2 rewrite NZplus_succ_l. now rewrite <- NZsucc_le_mono.
-Qed.
-
-Theorem NZplus_le_mono_r : forall n m p : NZ, n <= m <-> n + p <= m + p.
-Proof.
-intros n m p.
-rewrite (NZplus_comm n p); rewrite (NZplus_comm m p); apply NZplus_le_mono_l.
-Qed.
-
-Theorem NZplus_le_mono : forall n m p q : NZ, n <= m -> p <= q -> n + p <= m + q.
-Proof.
-intros n m p q H1 H2.
-apply NZle_trans with (m + p);
-[now apply -> NZplus_le_mono_r | now apply -> NZplus_le_mono_l].
-Qed.
-
-Theorem NZplus_lt_le_mono : forall n m p q : NZ, n < m -> p <= q -> n + p < m + q.
-Proof.
-intros n m p q H1 H2.
-apply NZlt_le_trans with (m + p);
-[now apply -> NZplus_lt_mono_r | now apply -> NZplus_le_mono_l].
-Qed.
-
-Theorem NZplus_le_lt_mono : forall n m p q : NZ, n <= m -> p < q -> n + p < m + q.
-Proof.
-intros n m p q H1 H2.
-apply NZle_lt_trans with (m + p);
-[now apply -> NZplus_le_mono_r | now apply -> NZplus_lt_mono_l].
-Qed.
-
-Theorem NZplus_pos_pos : forall n m : NZ, 0 < n -> 0 < m -> 0 < n + m.
-Proof.
-intros n m H1 H2. rewrite <- (NZplus_0_l 0). now apply NZplus_lt_mono.
-Qed.
-
-Theorem NZplus_pos_nonneg : forall n m : NZ, 0 < n -> 0 <= m -> 0 < n + m.
-Proof.
-intros n m H1 H2. rewrite <- (NZplus_0_l 0). now apply NZplus_lt_le_mono.
-Qed.
-
-Theorem NZplus_nonneg_pos : forall n m : NZ, 0 <= n -> 0 < m -> 0 < n + m.
-Proof.
-intros n m H1 H2. rewrite <- (NZplus_0_l 0). now apply NZplus_le_lt_mono.
-Qed.
-
-Theorem NZplus_nonneg_nonneg : forall n m : NZ, 0 <= n -> 0 <= m -> 0 <= n + m.
-Proof.
-intros n m H1 H2. rewrite <- (NZplus_0_l 0). now apply NZplus_le_mono.
-Qed.
-
-Theorem NZlt_plus_pos_l : forall n m : NZ, 0 < n -> m < n + m.
-Proof.
-intros n m H. apply -> (NZplus_lt_mono_r 0 n m) in H.
-now rewrite NZplus_0_l in H.
-Qed.
-
-Theorem NZlt_plus_pos_r : forall n m : NZ, 0 < n -> m < m + n.
-Proof.
-intros; rewrite NZplus_comm; now apply NZlt_plus_pos_l.
-Qed.
-
-Theorem NZle_lt_plus_lt : forall n m p q : NZ, n <= m -> p + m < q + n -> p < q.
-Proof.
-intros n m p q H1 H2. destruct (NZle_gt_cases q p); [| assumption].
-pose proof (NZplus_le_mono q p n m H H1) as H3. apply <- NZnle_gt in H2.
-false_hyp H3 H2.
-Qed.
-
-Theorem NZlt_le_plus_lt : forall n m p q : NZ, n < m -> p + m <= q + n -> p < q.
-Proof.
-intros n m p q H1 H2. destruct (NZle_gt_cases q p); [| assumption].
-pose proof (NZplus_le_lt_mono q p n m H H1) as H3. apply <- NZnle_gt in H3.
-false_hyp H2 H3.
-Qed.
-
-Theorem NZle_le_plus_le : forall n m p q : NZ, n <= m -> p + m <= q + n -> p <= q.
-Proof.
-intros n m p q H1 H2. destruct (NZle_gt_cases p q); [assumption |].
-pose proof (NZplus_lt_le_mono q p n m H H1) as H3. apply <- NZnle_gt in H3.
-false_hyp H2 H3.
-Qed.
-
-Theorem NZplus_lt_cases : forall n m p q : NZ, n + m < p + q -> n < p \/ m < q.
-Proof.
-intros n m p q H;
-destruct (NZle_gt_cases p n) as [H1 | H1].
-destruct (NZle_gt_cases q m) as [H2 | H2].
-pose proof (NZplus_le_mono p n q m H1 H2) as H3. apply -> NZle_ngt in H3.
-false_hyp H H3.
-now right. now left.
-Qed.
-
-Theorem NZplus_le_cases : forall n m p q : NZ, n + m <= p + q -> n <= p \/ m <= q.
-Proof.
-intros n m p q H.
-destruct (NZle_gt_cases n p) as [H1 | H1]. now left.
-destruct (NZle_gt_cases m q) as [H2 | H2]. now right.
-assert (H3 : p + q < n + m) by now apply NZplus_lt_mono.
-apply -> NZle_ngt in H. false_hyp H3 H.
-Qed.
-
-Theorem NZplus_neg_cases : forall n m : NZ, n + m < 0 -> n < 0 \/ m < 0.
-Proof.
-intros n m H; apply NZplus_lt_cases; now rewrite NZplus_0_l.
-Qed.
-
-Theorem NZplus_pos_cases : forall n m : NZ, 0 < n + m -> 0 < n \/ 0 < m.
-Proof.
-intros n m H; apply NZplus_lt_cases; now rewrite NZplus_0_l.
-Qed.
-
-Theorem NZplus_nonpos_cases : forall n m : NZ, n + m <= 0 -> n <= 0 \/ m <= 0.
-Proof.
-intros n m H; apply NZplus_le_cases; now rewrite NZplus_0_l.
-Qed.
-
-Theorem NZplus_nonneg_cases : forall n m : NZ, 0 <= n + m -> 0 <= n \/ 0 <= m.
-Proof.
-intros n m H; apply NZplus_le_cases; now rewrite NZplus_0_l.
-Qed.
-
-(** Multiplication and order *)
-
Theorem NZtimes_lt_pred :
forall p q n m : NZ, S p == q -> (p * n < p * m <-> q * n + m < q * m + n).
Proof.
@@ -299,7 +150,7 @@ intros n m p. rewrite (NZtimes_comm n p); rewrite (NZtimes_comm m p);
apply NZtimes_le_mono_neg_l.
Qed.
-Theorem NZtimes_lt_mono :
+Theorem NZtimes_lt_mono_nonneg :
forall n m p q : NZ, 0 <= n -> n < m -> 0 <= p -> p < q -> n * p < m * q.
Proof.
intros n m p q H1 H2 H3 H4.
@@ -311,12 +162,12 @@ Qed.
(* There are still many variants of the theorem above. One can assume 0 < n
or 0 < p or n <= m or p <= q. *)
-Theorem NZtimes_le_mono :
+Theorem NZtimes_le_mono_nonneg :
forall n m p q : NZ, 0 <= n -> n <= m -> 0 <= p -> p <= q -> n * p <= m * q.
Proof.
intros n m p q H1 H2 H3 H4.
le_elim H2; le_elim H4.
-apply NZlt_le_incl; now apply NZtimes_lt_mono.
+apply NZlt_le_incl; now apply NZtimes_lt_mono_nonneg.
rewrite <- H4; apply NZtimes_le_mono_nonneg_r; [assumption | now apply NZlt_le_incl].
rewrite <- H2; apply NZtimes_le_mono_nonneg_l; [assumption | now apply NZlt_le_incl].
rewrite H2; rewrite H4; now apply NZeq_le_incl.
@@ -328,46 +179,23 @@ intros n m H1 H2.
rewrite <- (NZtimes_0_l m). now apply -> NZtimes_lt_mono_pos_r.
Qed.
-Theorem NZtimes_nonneg_nonneg : forall n m : NZ, 0 <= n -> 0 <= m -> 0 <= n * m.
-Proof.
-intros n m H1 H2.
-rewrite <- (NZtimes_0_l m). now apply NZtimes_le_mono_nonneg_r.
-Qed.
-
Theorem NZtimes_neg_neg : forall n m : NZ, n < 0 -> m < 0 -> 0 < n * m.
Proof.
intros n m H1 H2.
rewrite <- (NZtimes_0_l m). now apply -> NZtimes_lt_mono_neg_r.
Qed.
-Theorem NZtimes_nonpos_nonpos : forall n m : NZ, n <= 0 -> m <= 0 -> 0 <= n * m.
-Proof.
-intros n m H1 H2.
-rewrite <- (NZtimes_0_l m). now apply NZtimes_le_mono_nonpos_r.
-Qed.
-
Theorem NZtimes_pos_neg : forall n m : NZ, 0 < n -> m < 0 -> n * m < 0.
Proof.
intros n m H1 H2.
rewrite <- (NZtimes_0_l m). now apply -> NZtimes_lt_mono_neg_r.
Qed.
-Theorem NZtimes_nonneg_nonpos : forall n m : NZ, 0 <= n -> m <= 0 -> n * m <= 0.
-Proof.
-intros n m H1 H2.
-rewrite <- (NZtimes_0_l m). now apply NZtimes_le_mono_nonpos_r.
-Qed.
-
Theorem NZtimes_neg_pos : forall n m : NZ, n < 0 -> 0 < m -> n * m < 0.
Proof.
intros; rewrite NZtimes_comm; now apply NZtimes_pos_neg.
Qed.
-Theorem NZtimes_nonpos_nonneg : forall n m : NZ, n <= 0 -> 0 <= m -> n * m <= 0.
-Proof.
-intros; rewrite NZtimes_comm; now apply NZtimes_nonneg_nonpos.
-Qed.
-
Theorem NZlt_1_times_pos : forall n m : NZ, 1 < n -> 0 < m -> 1 < n * m.
Proof.
intros n m H1 H2. apply -> (NZtimes_lt_mono_pos_r m) in H1.
@@ -408,7 +236,7 @@ intros n m H1 H2; apply -> NZeq_times_0 in H1. destruct H1 as [H1 | H1].
false_hyp H1 H2. assumption.
Qed.
-Theorem NZtimes_pos : forall n m : NZ, 0 < n * m <-> (0 < n /\ 0 < m) \/ (m < 0 /\ n < 0).
+Theorem NZlt_0_times : forall n m : NZ, 0 < n * m <-> (0 < n /\ 0 < m) \/ (m < 0 /\ n < 0).
Proof.
intros n m; split; [intro H | intros [[H1 H2] | [H1 H2]]].
destruct (NZlt_trichotomy n 0) as [H1 | [H1 | H1]];
@@ -423,20 +251,35 @@ elimtype False; now apply (NZlt_asymm (n * m) 0).
now apply NZtimes_pos_pos. now apply NZtimes_neg_neg.
Qed.
-Theorem NZtimes_neg :
- forall n m : NZ, n * m < 0 <-> (n < 0 /\ m > 0) \/ (n > 0 /\ m < 0).
+Theorem NZsquare_lt_mono_nonneg : forall n m : NZ, 0 <= n -> n < m -> n * n < m * m.
Proof.
-intros n m; split; [intro H | intros [[H1 H2] | [H1 H2]]].
-destruct (NZlt_trichotomy n 0) as [H1 | [H1 | H1]];
-[| rewrite H1 in H; rewrite NZtimes_0_l in H; false_hyp H NZlt_irrefl |];
-(destruct (NZlt_trichotomy m 0) as [H2 | [H2 | H2]];
-[| rewrite H2 in H; rewrite NZtimes_0_r in H; false_hyp H NZlt_irrefl |]);
-try (left; now split); try (right; now split).
-assert (H3 : n * m > 0) by now apply NZtimes_neg_neg.
-elimtype False; now apply (NZlt_asymm (n * m) 0).
-assert (H3 : n * m > 0) by now apply NZtimes_pos_pos.
-elimtype False; now apply (NZlt_asymm (n * m) 0).
-now apply NZtimes_neg_pos. now apply NZtimes_pos_neg.
+intros n m H1 H2. now apply NZtimes_lt_mono_nonneg.
+Qed.
+
+Theorem NZsquare_le_mono_nonneg : forall n m : NZ, 0 <= n -> n <= m -> n * n <= m * m.
+Proof.
+intros n m H1 H2. now apply NZtimes_le_mono_nonneg.
+Qed.
+
+(* The converse theorems require nonnegativity (or nonpositivity) of the
+other variable *)
+
+Theorem NZsquare_lt_simpl_nonneg : forall n m : NZ, 0 <= m -> n * n < m * m -> n < m.
+Proof.
+intros n m H1 H2. destruct (NZlt_ge_cases n 0).
+now apply NZlt_le_trans with 0.
+destruct (NZlt_ge_cases n m).
+assumption. assert (F : m * m <= n * n) by now apply NZsquare_le_mono_nonneg.
+apply -> NZle_ngt in F. false_hyp H2 F.
+Qed.
+
+Theorem NZsquare_le_simpl_nonneg : forall n m : NZ, 0 <= m -> n * n <= m * m -> n <= m.
+Proof.
+intros n m H1 H2. destruct (NZlt_ge_cases n 0).
+apply NZlt_le_incl; now apply NZlt_le_trans with 0.
+destruct (NZle_gt_cases n m).
+assumption. assert (F : m * m < n * n) by now apply NZsquare_lt_mono_nonneg.
+apply -> NZlt_nge in F. false_hyp H2 F.
Qed.
Theorem NZtimes_2_mono_l : forall n m : NZ, n < m -> 1 + (1 + 1) * n < (1 + 1) * m.
diff --git a/theories/Numbers/Natural/Abstract/NBase.v b/theories/Numbers/Natural/Abstract/NBase.v
index bcef66867..956eca896 100644
--- a/theories/Numbers/Natural/Abstract/NBase.v
+++ b/theories/Numbers/Natural/Abstract/NBase.v
@@ -45,6 +45,15 @@ Proof NZpred_succ.
Theorem pred_0 : P 0 == 0.
Proof pred_0.
+Theorem Neq_refl : forall n : N, n == n.
+Proof (proj1 NZeq_equiv).
+
+Theorem Neq_symm : forall n m : N, n == m -> m == n.
+Proof (proj2 (proj2 NZeq_equiv)).
+
+Theorem Neq_trans : forall n m p : N, n == m -> m == p -> n == p.
+Proof (proj1 (proj2 NZeq_equiv)).
+
Theorem neq_symm : forall n m : N, n ~= m -> m ~= n.
Proof NZneq_symm.
diff --git a/theories/Numbers/Natural/Abstract/NOrder.v b/theories/Numbers/Natural/Abstract/NOrder.v
index 33214cd1b..c7b7d495f 100644
--- a/theories/Numbers/Natural/Abstract/NOrder.v
+++ b/theories/Numbers/Natural/Abstract/NOrder.v
@@ -80,6 +80,12 @@ Proof NZlt_succ_diag_r.
Theorem le_succ_diag_r : forall n : N, n <= S n.
Proof NZle_succ_diag_r.
+Theorem lt_0_1 : 0 < 1.
+Proof NZlt_0_1.
+
+Theorem le_0_1 : 0 <= 1.
+Proof NZle_0_1.
+
Theorem lt_lt_succ_r : forall n m : N, n < m -> n < S m.
Proof NZlt_lt_succ_r.
diff --git a/theories/Numbers/Natural/Abstract/NTimesOrder.v b/theories/Numbers/Natural/Abstract/NTimesOrder.v
index d6c0bfafa..502f99417 100644
--- a/theories/Numbers/Natural/Abstract/NTimesOrder.v
+++ b/theories/Numbers/Natural/Abstract/NTimesOrder.v
@@ -56,6 +56,20 @@ Proof NZeq_times_0_l.
Theorem eq_times_0_r : forall n m : N, n * m == 0 -> n ~= 0 -> m == 0.
Proof NZeq_times_0_r.
+Theorem square_lt_mono : forall n m : N, n < m <-> n * n < m * m.
+Proof.
+intros n m; split; intro;
+[apply NZsquare_lt_mono_nonneg | apply NZsquare_lt_simpl_nonneg];
+try assumption; apply le_0_l.
+Qed.
+
+Theorem square_le_mono : forall n m : N, n <= m <-> n * n <= m * m.
+Proof.
+intros n m; split; intro;
+[apply NZsquare_le_mono_nonneg | apply NZsquare_le_simpl_nonneg];
+try assumption; apply le_0_l.
+Qed.
+
Theorem times_2_mono_l : forall n m : N, n < m -> 1 + (1 + 1) * n < (1 + 1) * m.
Proof NZtimes_2_mono_l.
@@ -73,21 +87,23 @@ Qed.
Theorem times_lt_mono : forall n m p q : N, n < m -> p < q -> n * p < m * q.
Proof.
-intros; apply NZtimes_lt_mono; try assumption; apply le_0_l.
+intros; apply NZtimes_lt_mono_nonneg; try assumption; apply le_0_l.
Qed.
Theorem times_le_mono : forall n m p q : N, n <= m -> p <= q -> n * p <= m * q.
Proof.
-intros; apply NZtimes_le_mono; try assumption; apply le_0_l.
+intros; apply NZtimes_le_mono_nonneg; try assumption; apply le_0_l.
Qed.
-Theorem times_pos : forall n m : N, n * m > 0 <-> n > 0 /\ m > 0.
+Theorem lt_0_times : forall n m : N, n * m > 0 <-> n > 0 /\ m > 0.
Proof.
intros n m; split; [intro H | intros [H1 H2]].
-apply -> NZtimes_pos in H. destruct H as [[H1 H2] | [H1 H2]]. now split. false_hyp H1 nlt_0_r.
+apply -> NZlt_0_times in H. destruct H as [[H1 H2] | [H1 H2]]. now split. false_hyp H1 nlt_0_r.
now apply NZtimes_pos_pos.
Qed.
+Notation times_pos := lt_0_times (only parsing).
+
Theorem eq_times_1 : forall n m : N, n * m == 1 <-> n == 1 /\ m == 1.
Proof.
intros n m.