diff options
author | herbelin <herbelin@85f007b7-540e-0410-9357-904b9bb8a0f7> | 2003-11-29 17:28:49 +0000 |
---|---|---|
committer | herbelin <herbelin@85f007b7-540e-0410-9357-904b9bb8a0f7> | 2003-11-29 17:28:49 +0000 |
commit | 9a6e3fe764dc2543dfa94de20fe5eec42d6be705 (patch) | |
tree | 77c0021911e3696a8c98e35a51840800db4be2a9 /theories/Reals/Rprod.v | |
parent | 9058fb97426307536f56c3e7447be2f70798e081 (diff) |
Remplacement des fichiers .v ancienne syntaxe de theories, contrib et states par les fichiers nouvelle syntaxe
git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@5027 85f007b7-540e-0410-9357-904b9bb8a0f7
Diffstat (limited to 'theories/Reals/Rprod.v')
-rw-r--r-- | theories/Reals/Rprod.v | 285 |
1 files changed, 156 insertions, 129 deletions
diff --git a/theories/Reals/Rprod.v b/theories/Reals/Rprod.v index c613c7647..9d962e125 100644 --- a/theories/Reals/Rprod.v +++ b/theories/Reals/Rprod.v @@ -8,157 +8,184 @@ (*i $Id$ i*) -Require Compare. -Require Rbase. -Require Rfunctions. -Require Rseries. -Require PartSum. -Require Binomial. -V7only [ Import nat_scope. Import Z_scope. Import R_scope. ]. +Require Import Compare. +Require Import Rbase. +Require Import Rfunctions. +Require Import Rseries. +Require Import PartSum. +Require Import Binomial. Open Local Scope R_scope. (* TT Ak; 1<=k<=N *) -Fixpoint prod_f_SO [An:nat->R;N:nat] : R := Cases N of - O => R1 -| (S p) => ``(prod_f_SO An p)*(An (S p))`` -end. +Fixpoint prod_f_SO (An:nat -> R) (N:nat) {struct N} : R := + match N with + | O => 1 + | S p => prod_f_SO An p * An (S p) + end. (**********) -Lemma prod_SO_split : (An:nat->R;n,k:nat) (le k n) -> (prod_f_SO An n)==(Rmult (prod_f_SO An k) (prod_f_SO [l:nat](An (plus k l)) (minus n k))). -Intros; Induction n. -Cut k=O; [Intro; Rewrite H0; Simpl; Ring | Inversion H; Reflexivity]. -Cut k=(S n)\/(le k n). -Intro; Elim H0; Intro. -Rewrite H1; Simpl; Rewrite <- minus_n_n; Simpl; Ring. -Replace (minus (S n) k) with (S (minus n k)). -Simpl; Replace (plus k (S (minus n k))) with (S n). -Rewrite Hrecn; [Ring | Assumption]. -Apply INR_eq; Rewrite S_INR; Rewrite plus_INR; Rewrite S_INR; Rewrite minus_INR; [Ring | Assumption]. -Apply INR_eq; Rewrite S_INR; Repeat Rewrite minus_INR. -Rewrite S_INR; Ring. -Apply le_trans with n; [Assumption | Apply le_n_Sn]. -Assumption. -Inversion H; [Left; Reflexivity | Right; Assumption]. +Lemma prod_SO_split : + forall (An:nat -> R) (n k:nat), + (k <= n)%nat -> + prod_f_SO An n = + prod_f_SO An k * prod_f_SO (fun l:nat => An (k + l)%nat) (n - k). +intros; induction n as [| n Hrecn]. +cut (k = 0%nat); + [ intro; rewrite H0; simpl in |- *; ring | inversion H; reflexivity ]. +cut (k = S n \/ (k <= n)%nat). +intro; elim H0; intro. +rewrite H1; simpl in |- *; rewrite <- minus_n_n; simpl in |- *; ring. +replace (S n - k)%nat with (S (n - k)). +simpl in |- *; replace (k + S (n - k))%nat with (S n). +rewrite Hrecn; [ ring | assumption ]. +apply INR_eq; rewrite S_INR; rewrite plus_INR; rewrite S_INR; + rewrite minus_INR; [ ring | assumption ]. +apply INR_eq; rewrite S_INR; repeat rewrite minus_INR. +rewrite S_INR; ring. +apply le_trans with n; [ assumption | apply le_n_Sn ]. +assumption. +inversion H; [ left; reflexivity | right; assumption ]. Qed. (**********) -Lemma prod_SO_pos : (An:nat->R;N:nat) ((n:nat)(le n N)->``0<=(An n)``) -> ``0<=(prod_f_SO An N)``. -Intros; Induction N. -Simpl; Left; Apply Rlt_R0_R1. -Simpl; Apply Rmult_le_pos. -Apply HrecN; Intros; Apply H; Apply le_trans with N; [Assumption | Apply le_n_Sn]. -Apply H; Apply le_n. +Lemma prod_SO_pos : + forall (An:nat -> R) (N:nat), + (forall n:nat, (n <= N)%nat -> 0 <= An n) -> 0 <= prod_f_SO An N. +intros; induction N as [| N HrecN]. +simpl in |- *; left; apply Rlt_0_1. +simpl in |- *; apply Rmult_le_pos. +apply HrecN; intros; apply H; apply le_trans with N; + [ assumption | apply le_n_Sn ]. +apply H; apply le_n. Qed. (**********) -Lemma prod_SO_Rle : (An,Bn:nat->R;N:nat) ((n:nat)(le n N)->``0<=(An n)<=(Bn n)``) -> ``(prod_f_SO An N)<=(prod_f_SO Bn N)``. -Intros; Induction N. -Right; Reflexivity. -Simpl; Apply Rle_trans with ``(prod_f_SO An N)*(Bn (S N))``. -Apply Rle_monotony. -Apply prod_SO_pos; Intros; Elim (H n (le_trans ? ? ? H0 (le_n_Sn N))); Intros; Assumption. -Elim (H (S N) (le_n (S N))); Intros; Assumption. -Do 2 Rewrite <- (Rmult_sym (Bn (S N))); Apply Rle_monotony. -Elim (H (S N) (le_n (S N))); Intros. -Apply Rle_trans with (An (S N)); Assumption. -Apply HrecN; Intros; Elim (H n (le_trans ? ? ? H0 (le_n_Sn N))); Intros; Split; Assumption. +Lemma prod_SO_Rle : + forall (An Bn:nat -> R) (N:nat), + (forall n:nat, (n <= N)%nat -> 0 <= An n <= Bn n) -> + prod_f_SO An N <= prod_f_SO Bn N. +intros; induction N as [| N HrecN]. +right; reflexivity. +simpl in |- *; apply Rle_trans with (prod_f_SO An N * Bn (S N)). +apply Rmult_le_compat_l. +apply prod_SO_pos; intros; elim (H n (le_trans _ _ _ H0 (le_n_Sn N))); intros; + assumption. +elim (H (S N) (le_n (S N))); intros; assumption. +do 2 rewrite <- (Rmult_comm (Bn (S N))); apply Rmult_le_compat_l. +elim (H (S N) (le_n (S N))); intros. +apply Rle_trans with (An (S N)); assumption. +apply HrecN; intros; elim (H n (le_trans _ _ _ H0 (le_n_Sn N))); intros; + split; assumption. Qed. (* Application to factorial *) -Lemma fact_prodSO : (n:nat) (INR (fact n))==(prod_f_SO [k:nat](INR k) n). -Intro; Induction n. -Reflexivity. -Change (INR (mult (S n) (fact n)))==(prod_f_SO ([k:nat](INR k)) (S n)). -Rewrite mult_INR; Rewrite Rmult_sym; Rewrite Hrecn; Reflexivity. +Lemma fact_prodSO : + forall n:nat, INR (fact n) = prod_f_SO (fun k:nat => INR k) n. +intro; induction n as [| n Hrecn]. +reflexivity. +change (INR (S n * fact n) = prod_f_SO (fun k:nat => INR k) (S n)) in |- *. +rewrite mult_INR; rewrite Rmult_comm; rewrite Hrecn; reflexivity. Qed. -Lemma le_n_2n : (n:nat) (le n (mult (2) n)). -Induction n. -Replace (mult (2) (O)) with O; [Apply le_n | Ring]. -Intros; Replace (mult (2) (S n0)) with (S (S (mult (2) n0))). -Apply le_n_S; Apply le_S; Assumption. -Replace (S (S (mult (2) n0))) with (plus (mult (2) n0) (2)); [Idtac | Ring]. -Replace (S n0) with (plus n0 (1)); [Idtac | Ring]. -Ring. +Lemma le_n_2n : forall n:nat, (n <= 2 * n)%nat. +simple induction n. +replace (2 * 0)%nat with 0%nat; [ apply le_n | ring ]. +intros; replace (2 * S n0)%nat with (S (S (2 * n0))). +apply le_n_S; apply le_S; assumption. +replace (S (S (2 * n0))) with (2 * n0 + 2)%nat; [ idtac | ring ]. +replace (S n0) with (n0 + 1)%nat; [ idtac | ring ]. +ring. Qed. (* We prove that (N!)²<=(2N-k)!*k! forall k in [|O;2N|] *) -Lemma RfactN_fact2N_factk : (N,k:nat) (le k (mult (2) N)) -> ``(Rsqr (INR (fact N)))<=(INR (fact (minus (mult (S (S O)) N) k)))*(INR (fact k))``. -Intros; Unfold Rsqr; Repeat Rewrite fact_prodSO. -Cut (le k N)\/(le N k). -Intro; Elim H0; Intro. -Rewrite (prod_SO_split [l:nat](INR l) (minus (mult (2) N) k) N). -Rewrite Rmult_assoc; Apply Rle_monotony. -Apply prod_SO_pos; Intros; Apply pos_INR. -Replace (minus (minus (mult (2) N) k) N) with (minus N k). -Rewrite Rmult_sym; Rewrite (prod_SO_split [l:nat](INR l) N k). -Apply Rle_monotony. -Apply prod_SO_pos; Intros; Apply pos_INR. -Apply prod_SO_Rle; Intros; Split. -Apply pos_INR. -Apply le_INR; Apply le_reg_r; Assumption. -Assumption. -Apply INR_eq; Repeat Rewrite minus_INR. -Rewrite mult_INR; Repeat Rewrite S_INR; Ring. -Apply le_trans with N; [Assumption | Apply le_n_2n]. -Apply simpl_le_plus_l with k; Rewrite <- le_plus_minus. -Replace (mult (2) N) with (plus N N); [Idtac | Ring]. -Apply le_reg_r; Assumption. -Assumption. -Assumption. -Apply simpl_le_plus_l with k; Rewrite <- le_plus_minus. -Replace (mult (2) N) with (plus N N); [Idtac | Ring]. -Apply le_reg_r; Assumption. -Assumption. -Rewrite <- (Rmult_sym (prod_f_SO [l:nat](INR l) k)); Rewrite (prod_SO_split [l:nat](INR l) k N). -Rewrite Rmult_assoc; Apply Rle_monotony. -Apply prod_SO_pos; Intros; Apply pos_INR. -Rewrite Rmult_sym; Rewrite (prod_SO_split [l:nat](INR l) N (minus (mult (2) N) k)). -Apply Rle_monotony. -Apply prod_SO_pos; Intros; Apply pos_INR. -Replace (minus N (minus (mult (2) N) k)) with (minus k N). -Apply prod_SO_Rle; Intros; Split. -Apply pos_INR. -Apply le_INR; Apply le_reg_r. -Apply simpl_le_plus_l with k; Rewrite <- le_plus_minus. -Replace (mult (2) N) with (plus N N); [Idtac | Ring]; Apply le_reg_r; Assumption. -Assumption. -Apply INR_eq; Repeat Rewrite minus_INR. -Rewrite mult_INR; Do 2 Rewrite S_INR; Ring. -Assumption. -Apply simpl_le_plus_l with k; Rewrite <- le_plus_minus. -Replace (mult (2) N) with (plus N N); [Idtac | Ring]; Apply le_reg_r; Assumption. -Assumption. -Assumption. -Apply simpl_le_plus_l with k; Rewrite <- le_plus_minus. -Replace (mult (2) N) with (plus N N); [Idtac | Ring]; Apply le_reg_r; Assumption. -Assumption. -Assumption. -Elim (le_dec k N); Intro; [Left; Assumption | Right; Assumption]. +Lemma RfactN_fact2N_factk : + forall N k:nat, + (k <= 2 * N)%nat -> + Rsqr (INR (fact N)) <= INR (fact (2 * N - k)) * INR (fact k). +intros; unfold Rsqr in |- *; repeat rewrite fact_prodSO. +cut ((k <= N)%nat \/ (N <= k)%nat). +intro; elim H0; intro. +rewrite (prod_SO_split (fun l:nat => INR l) (2 * N - k) N). +rewrite Rmult_assoc; apply Rmult_le_compat_l. +apply prod_SO_pos; intros; apply pos_INR. +replace (2 * N - k - N)%nat with (N - k)%nat. +rewrite Rmult_comm; rewrite (prod_SO_split (fun l:nat => INR l) N k). +apply Rmult_le_compat_l. +apply prod_SO_pos; intros; apply pos_INR. +apply prod_SO_Rle; intros; split. +apply pos_INR. +apply le_INR; apply plus_le_compat_r; assumption. +assumption. +apply INR_eq; repeat rewrite minus_INR. +rewrite mult_INR; repeat rewrite S_INR; ring. +apply le_trans with N; [ assumption | apply le_n_2n ]. +apply (fun p n m:nat => plus_le_reg_l n m p) with k; rewrite <- le_plus_minus. +replace (2 * N)%nat with (N + N)%nat; [ idtac | ring ]. +apply plus_le_compat_r; assumption. +assumption. +assumption. +apply (fun p n m:nat => plus_le_reg_l n m p) with k; rewrite <- le_plus_minus. +replace (2 * N)%nat with (N + N)%nat; [ idtac | ring ]. +apply plus_le_compat_r; assumption. +assumption. +rewrite <- (Rmult_comm (prod_f_SO (fun l:nat => INR l) k)); + rewrite (prod_SO_split (fun l:nat => INR l) k N). +rewrite Rmult_assoc; apply Rmult_le_compat_l. +apply prod_SO_pos; intros; apply pos_INR. +rewrite Rmult_comm; + rewrite (prod_SO_split (fun l:nat => INR l) N (2 * N - k)). +apply Rmult_le_compat_l. +apply prod_SO_pos; intros; apply pos_INR. +replace (N - (2 * N - k))%nat with (k - N)%nat. +apply prod_SO_Rle; intros; split. +apply pos_INR. +apply le_INR; apply plus_le_compat_r. +apply (fun p n m:nat => plus_le_reg_l n m p) with k; rewrite <- le_plus_minus. +replace (2 * N)%nat with (N + N)%nat; [ idtac | ring ]; + apply plus_le_compat_r; assumption. +assumption. +apply INR_eq; repeat rewrite minus_INR. +rewrite mult_INR; do 2 rewrite S_INR; ring. +assumption. +apply (fun p n m:nat => plus_le_reg_l n m p) with k; rewrite <- le_plus_minus. +replace (2 * N)%nat with (N + N)%nat; [ idtac | ring ]; + apply plus_le_compat_r; assumption. +assumption. +assumption. +apply (fun p n m:nat => plus_le_reg_l n m p) with k; rewrite <- le_plus_minus. +replace (2 * N)%nat with (N + N)%nat; [ idtac | ring ]; + apply plus_le_compat_r; assumption. +assumption. +assumption. +elim (le_dec k N); intro; [ left; assumption | right; assumption ]. Qed. (**********) -Lemma INR_fact_lt_0 : (n:nat) ``0<(INR (fact n))``. -Intro; Apply lt_INR_0; Apply neq_O_lt; Red; Intro; Elim (fact_neq_0 n); Symmetry; Assumption. +Lemma INR_fact_lt_0 : forall n:nat, 0 < INR (fact n). +intro; apply lt_INR_0; apply neq_O_lt; red in |- *; intro; + elim (fact_neq_0 n); symmetry in |- *; assumption. Qed. (* We have the following inequality : (C 2N k) <= (C 2N N) forall k in [|O;2N|] *) -Lemma C_maj : (N,k:nat) (le k (mult (2) N)) -> ``(C (mult (S (S O)) N) k)<=(C (mult (S (S O)) N) N)``. -Intros; Unfold C; Unfold Rdiv; Apply Rle_monotony. -Apply pos_INR. -Replace (minus (mult (2) N) N) with N. -Apply Rle_monotony_contra with ``((INR (fact N))*(INR (fact N)))``. -Apply Rmult_lt_pos; Apply INR_fact_lt_0. -Rewrite <- Rinv_r_sym. -Rewrite Rmult_sym; Apply Rle_monotony_contra with ``((INR (fact k))* - (INR (fact (minus (mult (S (S O)) N) k))))``. -Apply Rmult_lt_pos; Apply INR_fact_lt_0. -Rewrite Rmult_1r; Rewrite <- mult_INR; Rewrite <- Rmult_assoc; Rewrite <- Rinv_r_sym. -Rewrite Rmult_1l; Rewrite mult_INR; Rewrite (Rmult_sym (INR (fact k))); Replace ``(INR (fact N))*(INR (fact N))`` with (Rsqr (INR (fact N))). -Apply RfactN_fact2N_factk. -Assumption. -Reflexivity. -Rewrite mult_INR; Apply prod_neq_R0; Apply INR_fact_neq_0. -Apply prod_neq_R0; Apply INR_fact_neq_0. -Apply INR_eq; Rewrite minus_INR; [Rewrite mult_INR; Do 2 Rewrite S_INR; Ring | Apply le_n_2n]. -Qed. +Lemma C_maj : forall N k:nat, (k <= 2 * N)%nat -> C (2 * N) k <= C (2 * N) N. +intros; unfold C in |- *; unfold Rdiv in |- *; apply Rmult_le_compat_l. +apply pos_INR. +replace (2 * N - N)%nat with N. +apply Rmult_le_reg_l with (INR (fact N) * INR (fact N)). +apply Rmult_lt_0_compat; apply INR_fact_lt_0. +rewrite <- Rinv_r_sym. +rewrite Rmult_comm; + apply Rmult_le_reg_l with (INR (fact k) * INR (fact (2 * N - k))). +apply Rmult_lt_0_compat; apply INR_fact_lt_0. +rewrite Rmult_1_r; rewrite <- mult_INR; rewrite <- Rmult_assoc; + rewrite <- Rinv_r_sym. +rewrite Rmult_1_l; rewrite mult_INR; rewrite (Rmult_comm (INR (fact k))); + replace (INR (fact N) * INR (fact N)) with (Rsqr (INR (fact N))). +apply RfactN_fact2N_factk. +assumption. +reflexivity. +rewrite mult_INR; apply prod_neq_R0; apply INR_fact_neq_0. +apply prod_neq_R0; apply INR_fact_neq_0. +apply INR_eq; rewrite minus_INR; + [ rewrite mult_INR; do 2 rewrite S_INR; ring | apply le_n_2n ]. +Qed.
\ No newline at end of file |