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Diffstat (limited to 'theories/Numbers/Integer/Abstract/ZLt.v')
-rw-r--r-- | theories/Numbers/Integer/Abstract/ZLt.v | 432 |
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diff --git a/theories/Numbers/Integer/Abstract/ZLt.v b/theories/Numbers/Integer/Abstract/ZLt.v new file mode 100644 index 00000000..2a88a535 --- /dev/null +++ b/theories/Numbers/Integer/Abstract/ZLt.v @@ -0,0 +1,432 @@ +(************************************************************************) +(* 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 $Id: ZLt.v 11040 2008-06-03 00:04:16Z letouzey $ i*) + +Require Export ZMul. + +Module ZOrderPropFunct (Import ZAxiomsMod : ZAxiomsSig). +Module Export ZMulPropMod := ZMulPropFunct ZAxiomsMod. +Open Local Scope IntScope. + +(* Axioms *) + +Theorem Zlt_wd : + forall n1 n2 : Z, n1 == n2 -> forall m1 m2 : Z, m1 == m2 -> (n1 < m1 <-> n2 < m2). +Proof NZlt_wd. + +Theorem Zle_wd : + forall n1 n2 : Z, n1 == n2 -> forall m1 m2 : Z, m1 == m2 -> (n1 <= m1 <-> n2 <= m2). +Proof NZle_wd. + +Theorem Zmin_wd : + forall n1 n2 : Z, n1 == n2 -> forall m1 m2 : Z, m1 == m2 -> Zmin n1 m1 == Zmin n2 m2. +Proof NZmin_wd. + +Theorem Zmax_wd : + forall n1 n2 : Z, n1 == n2 -> forall m1 m2 : Z, m1 == m2 -> Zmax n1 m1 == Zmax n2 m2. +Proof NZmax_wd. + +Theorem Zlt_eq_cases : forall n m : Z, n <= m <-> n < m \/ n == m. +Proof NZlt_eq_cases. + +Theorem Zlt_irrefl : forall n : Z, ~ n < n. +Proof NZlt_irrefl. + +Theorem Zlt_succ_r : forall n m : Z, n < S m <-> n <= m. +Proof NZlt_succ_r. + +Theorem Zmin_l : forall n m : Z, n <= m -> Zmin n m == n. +Proof NZmin_l. + +Theorem Zmin_r : forall n m : Z, m <= n -> Zmin n m == m. +Proof NZmin_r. + +Theorem Zmax_l : forall n m : Z, m <= n -> Zmax n m == n. +Proof NZmax_l. + +Theorem Zmax_r : forall n m : Z, n <= m -> Zmax n m == m. +Proof NZmax_r. + +(* Renaming theorems from NZOrder.v *) + +Theorem Zlt_le_incl : forall n m : Z, n < m -> n <= m. +Proof NZlt_le_incl. + +Theorem Zlt_neq : forall n m : Z, n < m -> n ~= m. +Proof NZlt_neq. + +Theorem Zle_neq : forall n m : Z, n < m <-> n <= m /\ n ~= m. +Proof NZle_neq. + +Theorem Zle_refl : forall n : Z, n <= n. +Proof NZle_refl. + +Theorem Zlt_succ_diag_r : forall n : Z, n < S n. +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. + +Theorem Zle_le_succ_r : forall n m : Z, n <= m -> n <= S m. +Proof NZle_le_succ_r. + +Theorem Zle_succ_r : forall n m : Z, n <= S m <-> n <= m \/ n == S m. +Proof NZle_succ_r. + +Theorem Zneq_succ_diag_l : forall n : Z, S n ~= n. +Proof NZneq_succ_diag_l. + +Theorem Zneq_succ_diag_r : forall n : Z, n ~= S n. +Proof NZneq_succ_diag_r. + +Theorem Znlt_succ_diag_l : forall n : Z, ~ S n < n. +Proof NZnlt_succ_diag_l. + +Theorem Znle_succ_diag_l : forall n : Z, ~ S n <= n. +Proof NZnle_succ_diag_l. + +Theorem Zle_succ_l : forall n m : Z, S n <= m <-> n < m. +Proof NZle_succ_l. + +Theorem Zlt_succ_l : forall n m : Z, S n < m -> n < m. +Proof NZlt_succ_l. + +Theorem Zsucc_lt_mono : forall n m : Z, n < m <-> S n < S m. +Proof NZsucc_lt_mono. + +Theorem Zsucc_le_mono : forall n m : Z, n <= m <-> S n <= S m. +Proof NZsucc_le_mono. + +Theorem Zlt_asymm : forall n m, n < m -> ~ m < n. +Proof NZlt_asymm. + +Notation Zlt_ngt := Zlt_asymm (only parsing). + +Theorem Zlt_trans : forall n m p : Z, n < m -> m < p -> n < p. +Proof NZlt_trans. + +Theorem Zle_trans : forall n m p : Z, n <= m -> m <= p -> n <= p. +Proof NZle_trans. + +Theorem Zle_lt_trans : forall n m p : Z, n <= m -> m < p -> n < p. +Proof NZle_lt_trans. + +Theorem Zlt_le_trans : forall n m p : Z, n < m -> m <= p -> n < p. +Proof NZlt_le_trans. + +Theorem Zle_antisymm : forall n m : Z, n <= m -> m <= n -> n == m. +Proof NZle_antisymm. + +Theorem Zlt_1_l : forall n m : Z, 0 < n -> n < m -> 1 < m. +Proof NZlt_1_l. + +(** Trichotomy, decidability, and double negation elimination *) + +Theorem Zlt_trichotomy : forall n m : Z, n < m \/ n == m \/ m < n. +Proof NZlt_trichotomy. + +Notation Zlt_eq_gt_cases := Zlt_trichotomy (only parsing). + +Theorem Zlt_gt_cases : forall n m : Z, n ~= m <-> n < m \/ n > m. +Proof NZlt_gt_cases. + +Theorem Zle_gt_cases : forall n m : Z, n <= m \/ n > m. +Proof NZle_gt_cases. + +Theorem Zlt_ge_cases : forall n m : Z, n < m \/ n >= m. +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. + +Theorem Znlt_ge : forall n m : Z, ~ n < m <-> n >= m. +Proof NZnlt_ge. + +Theorem Zlt_dec : forall n m : Z, decidable (n < m). +Proof NZlt_dec. + +Theorem Zlt_dne : forall n m, ~ ~ n < m <-> n < m. +Proof NZlt_dne. + +Theorem Znle_gt : forall n m : Z, ~ n <= m <-> n > m. +Proof NZnle_gt. + +Theorem Zlt_nge : forall n m : Z, n < m <-> ~ n >= m. +Proof NZlt_nge. + +Theorem Zle_dec : forall n m : Z, decidable (n <= m). +Proof NZle_dec. + +Theorem Zle_dne : forall n m : Z, ~ ~ n <= m <-> n <= m. +Proof NZle_dne. + +Theorem Znlt_succ_r : forall n m : Z, ~ m < S n <-> n < m. +Proof NZnlt_succ_r. + +Theorem Zlt_exists_pred : + forall z n : Z, z < n -> exists k : Z, n == S k /\ z <= k. +Proof NZlt_exists_pred. + +Theorem Zlt_succ_iter_r : + forall (n : nat) (m : Z), m < NZsucc_iter (Datatypes.S n) m. +Proof NZlt_succ_iter_r. + +Theorem Zneq_succ_iter_l : + forall (n : nat) (m : Z), NZsucc_iter (Datatypes.S n) m ~= m. +Proof NZneq_succ_iter_l. + +(** Stronger variant of induction with assumptions n >= 0 (n < 0) +in the induction step *) + +Theorem Zright_induction : + forall A : Z -> Prop, predicate_wd Zeq A -> + forall z : Z, A z -> + (forall n : Z, z <= n -> A n -> A (S n)) -> + forall n : Z, z <= n -> A n. +Proof NZright_induction. + +Theorem Zleft_induction : + forall A : Z -> Prop, predicate_wd Zeq A -> + forall z : Z, A z -> + (forall n : Z, n < z -> A (S n) -> A n) -> + forall n : Z, n <= z -> A n. +Proof NZleft_induction. + +Theorem Zright_induction' : + forall A : Z -> Prop, predicate_wd Zeq A -> + forall z : Z, + (forall n : Z, n <= z -> A n) -> + (forall n : Z, z <= n -> A n -> A (S n)) -> + forall n : Z, A n. +Proof NZright_induction'. + +Theorem Zleft_induction' : + forall A : Z -> Prop, predicate_wd Zeq A -> + forall z : Z, + (forall n : Z, z <= n -> A n) -> + (forall n : Z, n < z -> A (S n) -> A n) -> + forall n : Z, A n. +Proof NZleft_induction'. + +Theorem Zstrong_right_induction : + forall A : Z -> Prop, predicate_wd Zeq A -> + forall z : Z, + (forall n : Z, z <= n -> (forall m : Z, z <= m -> m < n -> A m) -> A n) -> + forall n : Z, z <= n -> A n. +Proof NZstrong_right_induction. + +Theorem Zstrong_left_induction : + forall A : Z -> Prop, predicate_wd Zeq A -> + forall z : Z, + (forall n : Z, n <= z -> (forall m : Z, m <= z -> S n <= m -> A m) -> A n) -> + forall n : Z, n <= z -> A n. +Proof NZstrong_left_induction. + +Theorem Zstrong_right_induction' : + forall A : Z -> Prop, predicate_wd Zeq A -> + forall z : Z, + (forall n : Z, n <= z -> A n) -> + (forall n : Z, z <= n -> (forall m : Z, z <= m -> m < n -> A m) -> A n) -> + forall n : Z, A n. +Proof NZstrong_right_induction'. + +Theorem Zstrong_left_induction' : + forall A : Z -> Prop, predicate_wd Zeq A -> + forall z : Z, + (forall n : Z, z <= n -> A n) -> + (forall n : Z, n <= z -> (forall m : Z, m <= z -> S n <= m -> A m) -> A n) -> + forall n : Z, A n. +Proof NZstrong_left_induction'. + +Theorem Zorder_induction : + forall A : Z -> Prop, predicate_wd Zeq A -> + forall z : Z, A z -> + (forall n : Z, z <= n -> A n -> A (S n)) -> + (forall n : Z, n < z -> A (S n) -> A n) -> + forall n : Z, A n. +Proof NZorder_induction. + +Theorem Zorder_induction' : + forall A : Z -> Prop, predicate_wd Zeq A -> + forall z : Z, A z -> + (forall n : Z, z <= n -> A n -> A (S n)) -> + (forall n : Z, n <= z -> A n -> A (P n)) -> + forall n : Z, A n. +Proof NZorder_induction'. + +Theorem Zorder_induction_0 : + forall A : Z -> Prop, predicate_wd Zeq A -> + A 0 -> + (forall n : Z, 0 <= n -> A n -> A (S n)) -> + (forall n : Z, n < 0 -> A (S n) -> A n) -> + forall n : Z, A n. +Proof NZorder_induction_0. + +Theorem Zorder_induction'_0 : + forall A : Z -> Prop, predicate_wd Zeq A -> + A 0 -> + (forall n : Z, 0 <= n -> A n -> A (S n)) -> + (forall n : Z, n <= 0 -> A n -> A (P n)) -> + forall n : Z, A n. +Proof NZorder_induction'_0. + +Ltac Zinduct n := induction_maker n ltac:(apply Zorder_induction_0). + +(** Elimintation principle for < *) + +Theorem Zlt_ind : + forall A : Z -> Prop, predicate_wd Zeq A -> + forall n : Z, A (S n) -> + (forall m : Z, n < m -> A m -> A (S m)) -> forall m : Z, n < m -> A m. +Proof NZlt_ind. + +(** Elimintation principle for <= *) + +Theorem Zle_ind : + forall A : Z -> Prop, predicate_wd Zeq A -> + forall n : Z, A n -> + (forall m : Z, n <= m -> A m -> A (S m)) -> forall m : Z, n <= m -> A m. +Proof NZle_ind. + +(** Well-founded relations *) + +Theorem Zlt_wf : forall z : Z, well_founded (fun n m : Z => z <= n /\ n < m). +Proof NZlt_wf. + +Theorem Zgt_wf : forall z : Z, well_founded (fun n m : Z => m < n /\ n <= z). +Proof NZgt_wf. + +(* Theorems that are either not valid on N or have different proofs on N and Z *) + +Theorem Zlt_pred_l : forall n : Z, P n < n. +Proof. +intro n; rewrite <- (Zsucc_pred n) at 2; apply Zlt_succ_diag_r. +Qed. + +Theorem Zle_pred_l : forall n : Z, P n <= n. +Proof. +intro; apply Zlt_le_incl; apply Zlt_pred_l. +Qed. + +Theorem Zlt_le_pred : forall n m : Z, n < m <-> n <= P m. +Proof. +intros n m; rewrite <- (Zsucc_pred m); rewrite Zpred_succ. apply Zlt_succ_r. +Qed. + +Theorem Znle_pred_r : forall n : Z, ~ n <= P n. +Proof. +intro; rewrite <- Zlt_le_pred; apply Zlt_irrefl. +Qed. + +Theorem Zlt_pred_le : forall n m : Z, P n < m <-> n <= m. +Proof. +intros n m; rewrite <- (Zsucc_pred n) at 2. +symmetry; apply Zle_succ_l. +Qed. + +Theorem Zlt_lt_pred : forall n m : Z, n < m -> P n < m. +Proof. +intros; apply <- Zlt_pred_le; now apply Zlt_le_incl. +Qed. + +Theorem Zle_le_pred : forall n m : Z, n <= m -> P n <= m. +Proof. +intros; apply Zlt_le_incl; now apply <- Zlt_pred_le. +Qed. + +Theorem Zlt_pred_lt : forall n m : Z, n < P m -> n < m. +Proof. +intros n m H; apply Zlt_trans with (P m); [assumption | apply Zlt_pred_l]. +Qed. + +Theorem Zle_pred_lt : forall n m : Z, n <= P m -> n <= m. +Proof. +intros; apply Zlt_le_incl; now apply <- Zlt_le_pred. +Qed. + +Theorem Zpred_lt_mono : forall n m : Z, n < m <-> P n < P m. +Proof. +intros; rewrite Zlt_le_pred; symmetry; apply Zlt_pred_le. +Qed. + +Theorem Zpred_le_mono : forall n m : Z, n <= m <-> P n <= P m. +Proof. +intros; rewrite <- Zlt_pred_le; now rewrite Zlt_le_pred. +Qed. + +Theorem Zlt_succ_lt_pred : forall n m : Z, S n < m <-> n < P m. +Proof. +intros n m; now rewrite (Zpred_lt_mono (S n) m), Zpred_succ. +Qed. + +Theorem Zle_succ_le_pred : forall n m : Z, S n <= m <-> n <= P m. +Proof. +intros n m; now rewrite (Zpred_le_mono (S n) m), Zpred_succ. +Qed. + +Theorem Zlt_pred_lt_succ : forall n m : Z, P n < m <-> n < S m. +Proof. +intros; rewrite Zlt_pred_le; symmetry; apply Zlt_succ_r. +Qed. + +Theorem Zle_pred_lt_succ : forall n m : Z, P n <= m <-> n <= S m. +Proof. +intros n m; now rewrite (Zpred_le_mono n (S m)), Zpred_succ. +Qed. + +Theorem Zneq_pred_l : forall n : Z, P n ~= n. +Proof. +intro; apply Zlt_neq; apply Zlt_pred_l. +Qed. + +Theorem Zlt_n1_r : forall n m : Z, n < m -> m < 0 -> n < -1. +Proof. +intros n m H1 H2. apply -> Zlt_le_pred in H2. +setoid_replace (P 0) with (-1) in H2. now apply NZlt_le_trans with m. +apply <- Zeq_opp_r. now rewrite Zopp_pred, Zopp_0. +Qed. + +End ZOrderPropFunct. + |