From 295e0da7cddce4b71ab6a8257ef3e7ee75ab46ba Mon Sep 17 00:00:00 2001 From: desmettr Date: Wed, 31 Jul 2002 09:47:49 +0000 Subject: Proprietes de l'exponentielle git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@2945 85f007b7-540e-0410-9357-904b9bb8a0f7 --- theories/Reals/Exp_prop.v | 892 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 892 insertions(+) create mode 100644 theories/Reals/Exp_prop.v diff --git a/theories/Reals/Exp_prop.v b/theories/Reals/Exp_prop.v new file mode 100644 index 0000000000..92f1e52935 --- /dev/null +++ b/theories/Reals/Exp_prop.v @@ -0,0 +1,892 @@ +(***********************************************************************) +(* v * The Coq Proof Assistant / The Coq Development Team *) +(* R := [N:nat](sum_f_R0 [k:nat]``/(INR (fact k))*(pow x k)`` N). + +Lemma E1_cvg : (x:R) (Un_cv (E1 x) (exp x)). +Intro; Unfold exp; Unfold projT1. +Case (exist_exp x); Intro. +Unfold exp_in Un_cv; Unfold infinit_sum E1; Trivial. +Qed. + +(* Le reste du produit de Cauchy des sommes partielles de l'exponentielle *) +Definition Reste_E [x,y:R] : nat->R := [N:nat](sum_f_R0 [k:nat](sum_f_R0 [l:nat]``/(INR (fact (S (plus l k))))*(pow x (S (plus l k)))*(/(INR (fact (minus N l)))*(pow y (minus N l)))`` (pred (minus N k))) (pred N)). + +Lemma exp_form : (x,y:R;n:nat) (lt O n) -> ``(E1 x n)*(E1 y n)-(Reste_E x y n)==(E1 (x+y) n)``. +Intros; Unfold E1. +Rewrite cauchy_finite. +Unfold Reste_E; Unfold Rminus; Rewrite Rplus_assoc; Rewrite Rplus_Ropp_r; Rewrite Rplus_Or; Apply sum_eq; Intros. +Rewrite binome. +Rewrite scal_sum; Apply sum_eq; Intros. +Unfold C; Unfold Rdiv; Repeat Rewrite Rmult_assoc; Rewrite (Rmult_sym (INR (fact i))); Repeat Rewrite Rmult_assoc; Rewrite <- Rinv_l_sym. +Rewrite Rmult_1r; Rewrite Rinv_Rmult. +Ring. +Apply INR_fact_neq_0. +Apply INR_fact_neq_0. +Apply INR_fact_neq_0. +Apply H. +Qed. + +(* Un majorant du reste *) +Definition maj_Reste_E [x,y:R] : nat->R := [N:nat]``4*(pow (Rmax R1 (Rmax (Rabsolu x) (Rabsolu y))) (mult (S (S O)) N))/(Rsqr (INR (fact (div2 (pred N)))))``. + +Lemma Rle_Rinv : (x,y:R) ``0 ``0 ``x<=y`` -> ``/y<=/x``. +Intros; Apply Rle_monotony_contra with x. +Apply H. +Rewrite <- Rinv_r_sym. +Apply Rle_monotony_contra with y. +Apply H0. +Rewrite Rmult_1r; Rewrite Rmult_sym; Rewrite Rmult_assoc; Rewrite <- Rinv_l_sym. +Rewrite Rmult_1r; Apply H1. +Red; Intro; Rewrite H2 in H0; Elim (Rlt_antirefl ? H0). +Red; Intro; Rewrite H2 in H; Elim (Rlt_antirefl ? H). +Qed. + +(**********) +Lemma div2_double : (N:nat) (div2 (mult (2) N))=N. +Intro; Induction N. +Reflexivity. +Replace (mult (2) (S N)) with (S (S (mult (2) N))). +Simpl; Simpl in HrecN; Rewrite HrecN; Reflexivity. +Apply INR_eq; Do 2 Rewrite S_INR; Do 2 Rewrite mult_INR; Repeat Rewrite S_INR; Ring. +Qed. + +Lemma div2_S_double : (N:nat) (div2 (S (mult (2) N)))=N. +Intro; Induction N. +Reflexivity. +Replace (mult (2) (S N)) with (S (S (mult (2) N))). +Simpl; Simpl in HrecN; Rewrite HrecN; Reflexivity. +Apply INR_eq; Do 2 Rewrite S_INR; Do 2 Rewrite mult_INR; Repeat Rewrite S_INR; Ring. +Qed. + +Lemma div2_not_R0 : (N:nat) (lt (1) N) -> (lt O (div2 N)). +Intros; Induction N. +Elim (lt_n_O ? H). +Cut (lt (1) N)\/N=(1). +Intro; Elim H0; Intro. +Assert H2 := (even_odd_dec N). +Elim H2; Intro. +Rewrite <- (even_div2 ? a); Apply HrecN; Assumption. +Rewrite <- (odd_div2 ? b); Apply lt_O_Sn. +Rewrite H1; Simpl; Apply lt_O_Sn. +Inversion H. +Right; Reflexivity. +Left; Apply lt_le_trans with (2); [Apply lt_n_Sn | Apply H1]. +Qed. + +(* Majoration du reste par une suite convergeant vers 0 *) +Lemma Reste_E_maj : (x,y:R;N:nat) (lt O N) -> ``(Rabsolu (Reste_E x y N))<=(maj_Reste_E x y N)``. +Intros; Pose M := (Rmax R1 (Rmax (Rabsolu x) (Rabsolu y))). +Apply Rle_trans with (Rmult (pow M (mult (2) N)) (sum_f_R0 [k:nat](sum_f_R0 [l:nat]``/(Rsqr (INR (fact (div2 (S N)))))`` (pred (minus N k))) (pred N))). +Unfold Reste_E. +Apply Rle_trans with (sum_f_R0 [k:nat](Rabsolu (sum_f_R0 [l:nat]``/(INR (fact (S (plus l k))))*(pow x (S (plus l k)))*(/(INR (fact (minus N l)))*(pow y (minus N l)))`` (pred (minus N k)))) (pred N)). +Apply (sum_Rabsolu [k:nat](sum_f_R0 [l:nat]``/(INR (fact (S (plus l k))))*(pow x (S (plus l k)))*(/(INR (fact (minus N l)))*(pow y (minus N l)))`` (pred (minus N k))) (pred N)). +Apply Rle_trans with (sum_f_R0 [k:nat](sum_f_R0 [l:nat]``(Rabsolu (/(INR (fact (S (plus l k))))*(pow x (S (plus l k)))*(/(INR (fact (minus N l)))*(pow y (minus N l)))))`` (pred (minus N k))) (pred N)). +Apply sum_Rle; Intros. +Apply (sum_Rabsolu [l:nat]``/(INR (fact (S (plus l n))))*(pow x (S (plus l n)))*(/(INR (fact (minus N l)))*(pow y (minus N l)))``). +Apply Rle_trans with (sum_f_R0 [k:nat](sum_f_R0 [l:nat]``(pow M (mult (S (S O)) N))*/(INR (fact (S l)))*/(INR (fact (minus N l)))`` (pred (minus N k))) (pred N)). +Apply sum_Rle; Intros. +Apply sum_Rle; Intros. +Repeat Rewrite Rabsolu_mult. +Do 2 Rewrite <- Pow_Rabsolu. +Rewrite (Rabsolu_right ``/(INR (fact (S (plus n0 n))))``). +Rewrite (Rabsolu_right ``/(INR (fact (minus N n0)))``). +Replace ``/(INR (fact (S (plus n0 n))))*(pow (Rabsolu x) (S (plus n0 n)))* + (/(INR (fact (minus N n0)))*(pow (Rabsolu y) (minus N n0)))`` with ``/(INR (fact (minus N n0)))*/(INR (fact (S (plus n0 n))))*(pow (Rabsolu x) (S (plus n0 n)))*(pow (Rabsolu y) (minus N n0))``; [Idtac | Ring]. +Rewrite <- (Rmult_sym ``/(INR (fact (minus N n0)))``). +Repeat Rewrite Rmult_assoc. +Apply Rle_monotony. +Left; Apply Rlt_Rinv; Apply INR_fact_lt_0. +Apply Rle_trans with ``/(INR (fact (S n0)))*(pow (Rabsolu x) (S (plus n0 n)))*(pow (Rabsolu y) (minus N n0))``. +Rewrite (Rmult_sym ``/(INR (fact (S (plus n0 n))))``); Rewrite (Rmult_sym ``/(INR (fact (S n0)))``); Repeat Rewrite Rmult_assoc; Apply Rle_monotony. +Apply pow_le; Apply Rabsolu_pos. +Rewrite (Rmult_sym ``/(INR (fact (S n0)))``); Apply Rle_monotony. +Apply pow_le; Apply Rabsolu_pos. +Apply Rle_Rinv. +Apply INR_fact_lt_0. +Apply INR_fact_lt_0. +Apply le_INR; Apply fact_growing; Apply le_n_S. +Apply le_plus_l. +Rewrite (Rmult_sym ``(pow M (mult (S (S O)) N))``); Rewrite Rmult_assoc; Apply Rle_monotony. +Left; Apply Rlt_Rinv; Apply INR_fact_lt_0. +Apply Rle_trans with ``(pow M (S (plus n0 n)))*(pow (Rabsolu y) (minus N n0))``. +Do 2 Rewrite <- (Rmult_sym ``(pow (Rabsolu y) (minus N n0))``). +Apply Rle_monotony. +Apply pow_le; Apply Rabsolu_pos. +Apply pow_incr; Split. +Apply Rabsolu_pos. +Apply Rle_trans with (Rmax (Rabsolu x) (Rabsolu y)). +Apply RmaxLess1. +Unfold M; Apply RmaxLess2. +Apply Rle_trans with ``(pow M (S (plus n0 n)))*(pow M (minus N n0))``. +Apply Rle_monotony. +Apply pow_le; Apply Rle_trans with R1. +Left; Apply Rlt_R0_R1. +Unfold M; Apply RmaxLess1. +Apply pow_incr; Split. +Apply Rabsolu_pos. +Apply Rle_trans with (Rmax (Rabsolu x) (Rabsolu y)). +Apply RmaxLess2. +Unfold M; Apply RmaxLess2. +Rewrite <- pow_add; Replace (plus (S (plus n0 n)) (minus N n0)) with (plus N (S n)). +Apply Rle_pow. +Unfold M; Apply RmaxLess1. +Replace (mult (2) N) with (plus N N); [Idtac | Ring]. +Apply le_reg_l. +Replace N with (S (pred N)). +Apply le_n_S; Apply H0. +Symmetry; Apply S_pred with O; Apply H. +Apply INR_eq; Do 2 Rewrite plus_INR; Do 2 Rewrite S_INR; Rewrite plus_INR; Rewrite minus_INR. +Ring. +Apply le_trans with (pred (minus N n)). +Apply H1. +Apply le_S_n. +Replace (S (pred (minus N n))) with (minus N n). +Apply le_trans with N. +Apply simpl_le_plus_l with n. +Rewrite <- le_plus_minus. +Apply le_plus_r. +Apply le_trans with (pred N). +Apply H0. +Apply le_pred_n. +Apply le_n_Sn. +Apply S_pred with O. +Apply simpl_lt_plus_l with n. +Rewrite <- le_plus_minus. +Replace (plus n (0)) with n; [Idtac | Ring]. +Apply le_lt_trans with (pred N). +Apply H0. +Apply lt_pred_n_n. +Apply H. +Apply le_trans with (pred N). +Apply H0. +Apply le_pred_n. +Apply Rle_sym1; Left; Apply Rlt_Rinv; Apply INR_fact_lt_0. +Apply Rle_sym1; Left; Apply Rlt_Rinv; Apply INR_fact_lt_0. +Rewrite scal_sum. +Apply sum_Rle; Intros. +Rewrite <- Rmult_sym. +Rewrite scal_sum. +Apply sum_Rle; Intros. +Rewrite (Rmult_sym ``/(Rsqr (INR (fact (div2 (S N)))))``). +Rewrite Rmult_assoc; Apply Rle_monotony. +Apply pow_le. +Apply Rle_trans with R1. +Left; Apply Rlt_R0_R1. +Unfold M; Apply RmaxLess1. +Assert H2 := (even_odd_cor N). +Elim H2; Intros N0 H3. +Elim H3; Intro. +Apply Rle_trans with ``/(INR (fact n0))*/(INR (fact (minus N n0)))``. +Do 2 Rewrite <- (Rmult_sym ``/(INR (fact (minus N n0)))``). +Apply Rle_monotony. +Left; Apply Rlt_Rinv; Apply INR_fact_lt_0. +Apply Rle_Rinv. +Apply INR_fact_lt_0. +Apply INR_fact_lt_0. +Apply le_INR. +Apply fact_growing. +Apply le_n_Sn. +Replace ``/(INR (fact n0))*/(INR (fact (minus N n0)))`` with ``(C N n0)/(INR (fact N))``. +Pattern 1 N; Rewrite H4. +Apply Rle_trans with ``(C N N0)/(INR (fact N))``. +Unfold Rdiv; Do 2 Rewrite <- (Rmult_sym ``/(INR (fact N))``). +Apply Rle_monotony. +Left; Apply Rlt_Rinv; Apply INR_fact_lt_0. +Rewrite H4. +Apply C_maj. +Rewrite <- H4; Apply le_trans with (pred (minus N n)). +Apply H1. +Apply le_S_n. +Replace (S (pred (minus N n))) with (minus N n). +Apply le_trans with N. +Apply simpl_le_plus_l with n. +Rewrite <- le_plus_minus. +Apply le_plus_r. +Apply le_trans with (pred N). +Apply H0. +Apply le_pred_n. +Apply le_n_Sn. +Apply S_pred with O. +Apply simpl_lt_plus_l with n. +Rewrite <- le_plus_minus. +Replace (plus n (0)) with n; [Idtac | Ring]. +Apply le_lt_trans with (pred N). +Apply H0. +Apply lt_pred_n_n. +Apply H. +Apply le_trans with (pred N). +Apply H0. +Apply le_pred_n. +Replace ``(C N N0)/(INR (fact N))`` with ``/(Rsqr (INR (fact N0)))``. +Rewrite H4; Rewrite div2_S_double; Right; Reflexivity. +Unfold Rsqr C Rdiv. +Repeat Rewrite Rinv_Rmult. +Rewrite (Rmult_sym (INR (fact N))). +Repeat Rewrite Rmult_assoc. +Rewrite <- Rinv_r_sym. +Rewrite Rmult_1r; Replace (minus N N0) with N0. +Ring. +Replace N with (plus N0 N0). +Symmetry; Apply minus_plus. +Rewrite H4. +Apply INR_eq; Rewrite plus_INR; Rewrite mult_INR; Do 2 Rewrite S_INR; Ring. +Apply INR_fact_neq_0. +Apply INR_fact_neq_0. +Apply INR_fact_neq_0. +Apply INR_fact_neq_0. +Apply INR_fact_neq_0. +Unfold C Rdiv. +Rewrite (Rmult_sym (INR (fact N))). +Repeat Rewrite Rmult_assoc. +Rewrite <- Rinv_r_sym. +Rewrite Rinv_Rmult. +Rewrite Rmult_1r; Ring. +Apply INR_fact_neq_0. +Apply INR_fact_neq_0. +Apply INR_fact_neq_0. +Replace ``/(INR (fact (S n0)))*/(INR (fact (minus N n0)))`` with ``(C (S N) (S n0))/(INR (fact (S N)))``. +Apply Rle_trans with ``(C (S N) (S N0))/(INR (fact (S N)))``. +Unfold Rdiv; Do 2 Rewrite <- (Rmult_sym ``/(INR (fact (S N)))``). +Apply Rle_monotony. +Left; Apply Rlt_Rinv; Apply INR_fact_lt_0. +Cut (S N) = (mult (2) (S N0)). +Intro; Rewrite H5; Apply C_maj. +Rewrite <- H5; Apply le_n_S. +Apply le_trans with (pred (minus N n)). +Apply H1. +Apply le_S_n. +Replace (S (pred (minus N n))) with (minus N n). +Apply le_trans with N. +Apply simpl_le_plus_l with n. +Rewrite <- le_plus_minus. +Apply le_plus_r. +Apply le_trans with (pred N). +Apply H0. +Apply le_pred_n. +Apply le_n_Sn. +Apply S_pred with O. +Apply simpl_lt_plus_l with n. +Rewrite <- le_plus_minus. +Replace (plus n (0)) with n; [Idtac | Ring]. +Apply le_lt_trans with (pred N). +Apply H0. +Apply lt_pred_n_n. +Apply H. +Apply le_trans with (pred N). +Apply H0. +Apply le_pred_n. +Apply INR_eq; Rewrite H4. +Do 2 Rewrite S_INR; Do 2 Rewrite mult_INR; Repeat Rewrite S_INR; Ring. +Cut (S N) = (mult (2) (S N0)). +Intro. +Replace ``(C (S N) (S N0))/(INR (fact (S N)))`` with ``/(Rsqr (INR (fact (S N0))))``. +Rewrite H5; Rewrite div2_double. +Right; Reflexivity. +Unfold Rsqr C Rdiv. +Repeat Rewrite Rinv_Rmult. +Replace (minus (S N) (S N0)) with (S N0). +Rewrite (Rmult_sym (INR (fact (S N)))). +Repeat Rewrite Rmult_assoc. +Rewrite <- Rinv_r_sym. +Rewrite Rmult_1r; Reflexivity. +Apply INR_fact_neq_0. +Replace (S N) with (plus (S N0) (S N0)). +Symmetry; Apply minus_plus. +Rewrite H5; Ring. +Apply INR_fact_neq_0. +Apply INR_fact_neq_0. +Apply INR_fact_neq_0. +Apply INR_fact_neq_0. +Apply INR_eq; Rewrite H4; Do 2 Rewrite S_INR; Do 2 Rewrite mult_INR; Repeat Rewrite S_INR; Ring. +Unfold C Rdiv. +Rewrite (Rmult_sym (INR (fact (S N)))). +Rewrite Rmult_assoc; Rewrite <- Rinv_r_sym. +Rewrite Rmult_1r; Rewrite Rinv_Rmult. +Reflexivity. +Apply INR_fact_neq_0. +Apply INR_fact_neq_0. +Apply INR_fact_neq_0. +Unfold maj_Reste_E. +Unfold Rdiv; Rewrite (Rmult_sym ``4``). +Rewrite Rmult_assoc. +Apply Rle_monotony. +Apply pow_le. +Apply Rle_trans with R1. +Left; Apply Rlt_R0_R1. +Apply RmaxLess1. +Apply Rle_trans with (sum_f_R0 [k:nat]``(INR (minus N k))*/(Rsqr (INR (fact (div2 (S N)))))`` (pred N)). +Apply sum_Rle; Intros. +Rewrite sum_cte. +Replace (S (pred (minus N n))) with (minus N n). +Right; Apply Rmult_sym. +Apply S_pred with O. +Apply simpl_lt_plus_l with n. +Rewrite <- le_plus_minus. +Replace (plus n (0)) with n; [Idtac | Ring]. +Apply le_lt_trans with (pred N). +Apply H0. +Apply lt_pred_n_n. +Apply H. +Apply le_trans with (pred N). +Apply H0. +Apply le_pred_n. +Apply Rle_trans with (sum_f_R0 [k:nat]``(INR N)*/(Rsqr (INR (fact (div2 (S N)))))`` (pred N)). +Apply sum_Rle; Intros. +Do 2 Rewrite <- (Rmult_sym ``/(Rsqr (INR (fact (div2 (S N)))))``). +Apply Rle_monotony. +Left; Apply Rlt_Rinv; Apply Rsqr_pos_lt. +Apply INR_fact_neq_0. +Apply le_INR. +Apply simpl_le_plus_l with n. +Rewrite <- le_plus_minus. +Apply le_plus_r. +Apply le_trans with (pred N). +Apply H0. +Apply le_pred_n. +Rewrite sum_cte; Replace (S (pred N)) with N. +Cut (div2 (S N)) = (S (div2 (pred N))). +Intro; Rewrite H0. +Rewrite fact_simpl; Rewrite mult_sym; Rewrite mult_INR; Rewrite Rsqr_times. +Rewrite Rinv_Rmult. +Rewrite (Rmult_sym (INR N)); Repeat Rewrite Rmult_assoc; Apply Rle_monotony. +Left; Apply Rlt_Rinv; Apply Rsqr_pos_lt; Apply INR_fact_neq_0. +Rewrite <- H0. +Cut ``(INR N)<=(INR (mult (S (S O)) (div2 (S N))))``. +Intro; Apply Rle_monotony_contra with ``(Rsqr (INR (div2 (S N))))``. +Apply Rsqr_pos_lt. +Apply not_O_INR; Red; Intro. +Cut (lt (1) (S N)). +Intro; Assert H4 := (div2_not_R0 ? H3). +Rewrite H2 in H4; Elim (lt_n_O ? H4). +Apply lt_n_S; Apply H. +Repeat Rewrite <- Rmult_assoc. +Rewrite <- Rinv_r_sym. +Rewrite Rmult_1l. +Replace ``(INR N)*(INR N)`` with (Rsqr (INR N)); [Idtac | Reflexivity]. +Rewrite Rmult_sym. +Replace ``4`` with (Rsqr ``2``); [Idtac | SqRing]. +Rewrite <- Rsqr_times. +Apply Rsqr_incr_1. +Replace ``2`` with (INR (2)). +Rewrite <- mult_INR; Apply H1. +Reflexivity. +Left; Apply lt_INR_0; Apply H. +Left; Apply Rmult_lt_pos. +Apply Rgt_2_0. +Apply lt_INR_0; Apply div2_not_R0. +Apply lt_n_S; Apply H. +Cut (lt (1) (S N)). +Intro; Unfold Rsqr; Apply prod_neq_R0; Apply not_O_INR; Intro; Assert H4 := (div2_not_R0 ? H2); Rewrite H3 in H4; Elim (lt_n_O ? H4). +Apply lt_n_S; Apply H. +Assert H1 := (even_odd_cor N). +Elim H1; Intros N0 H2. +Elim H2; Intro. +Pattern 2 N; Rewrite H3. +Rewrite div2_S_double. +Right; Rewrite H3; Reflexivity. +Pattern 2 N; Rewrite H3. +Replace (S (S (mult (2) N0))) with (mult (2) (S N0)). +Rewrite div2_double. +Rewrite H3. +Rewrite S_INR; Do 2 Rewrite mult_INR. +Rewrite (S_INR N0). +Rewrite Rmult_Rplus_distr. +Apply Rle_compatibility. +Rewrite Rmult_1r. +Simpl. +Pattern 1 R1; Rewrite <- Rplus_Or; Apply Rle_compatibility; Left; Apply Rlt_R0_R1. +Apply INR_eq; Do 2 Rewrite S_INR; Do 2 Rewrite mult_INR; Repeat Rewrite S_INR; Ring. +Unfold Rsqr; Apply prod_neq_R0; Apply INR_fact_neq_0. +Unfold Rsqr; Apply prod_neq_R0; Apply not_O_INR; Discriminate. +Assert H0 := (even_odd_cor N). +Elim H0; Intros N0 H1. +Elim H1; Intro. +Cut (lt O N0). +Intro; Rewrite H2. +Rewrite div2_S_double. +Replace (mult (2) N0) with (S (S (mult (2) (pred N0)))). +Replace (pred (S (S (mult (2) (pred N0))))) with (S (mult (2) (pred N0))). +Rewrite div2_S_double. +Apply S_pred with O; Apply H3. +Reflexivity. +Replace N0 with (S (pred N0)). +Apply INR_eq; Do 2 Rewrite S_INR; Do 2 Rewrite mult_INR; Repeat Rewrite S_INR; Ring. +Symmetry; Apply S_pred with O; Apply H3. +Rewrite H2 in H. +Apply neq_O_lt. +Red; Intro. +Rewrite <- H3 in H. +Simpl in H. +Elim (lt_n_O ? H). +Rewrite H2. +Replace (pred (S (mult (2) N0))) with (mult (2) N0); [Idtac | Reflexivity]. +Replace (S (S (mult (2) N0))) with (mult (2) (S N0)). +Do 2 Rewrite div2_double. +Reflexivity. +Apply INR_eq; Do 2 Rewrite S_INR; Do 2 Rewrite mult_INR; Repeat Rewrite S_INR; Ring. +Apply S_pred with O; Apply H. +Qed. + +Lemma maj_Reste_cv_R0 : (x,y:R) (Un_cv (maj_Reste_E x y) ``0``). +Intros; Assert H := (Majxy_cv_R0 x y). +Unfold Un_cv in H; Unfold Un_cv; Intros. +Cut ``0 ``0<(exp x)``. +Intros; Pose An := [N:nat]``/(INR (fact N))*(pow x N)``. +Cut (Un_cv [n:nat](sum_f_R0 An n) (exp x)). +Intro; Apply Rlt_le_trans with (sum_f_R0 An O). +Unfold An; Simpl; Rewrite Rinv_R1; Rewrite Rmult_1r; Apply Rlt_R0_R1. +Apply sum_incr. +Assumption. +Intro; Unfold An; Left; Apply Rmult_lt_pos. +Apply Rlt_Rinv; Apply INR_fact_lt_0. +Apply (pow_lt ? n H). +Unfold exp; Unfold projT1; Case (exist_exp x); Intro. +Unfold exp_in; Unfold infinit_sum Un_cv; Trivial. +Qed. + +(**********) +Lemma exp_pos : (x:R) ``0<(exp x)``. +Intro; Case (total_order_T R0 x); Intro. +Elim s; Intro. +Apply (exp_pos_pos ? a). +Rewrite <- b; Rewrite exp_0; Apply Rlt_R0_R1. +Replace (exp x) with ``1/(exp (-x))``. +Unfold Rdiv; Apply Rmult_lt_pos. +Apply Rlt_R0_R1. +Apply Rlt_Rinv; Apply exp_pos_pos. +Apply (Rgt_RO_Ropp ? r). +Cut ``(exp (-x))<>0``. +Intro; Unfold Rdiv; Apply r_Rmult_mult with ``(exp (-x))``. +Rewrite Rmult_1l; Rewrite <- Rinv_r_sym. +Rewrite <- exp_plus. +Rewrite Rplus_Ropp_l; Rewrite exp_0; Reflexivity. +Apply H. +Apply H. +Assert H := (exp_plus x ``-x``). +Rewrite Rplus_Ropp_r in H; Rewrite exp_0 in H. +Red; Intro; Rewrite H0 in H. +Rewrite Rmult_Or in H. +Elim R1_neq_R0; Assumption. +Qed. + +(* ((exp h)-1)/h -> 0 quand h->0 *) +Lemma derivable_pt_lim_exp_0 : (derivable_pt_lim exp ``0`` ``1``). +Unfold derivable_pt_lim; Intros. +Pose fn := [N:nat][x:R]``(pow x N)/(INR (fact (S N)))``. +Cut (CVN_R fn). +Intro; Cut (x:R)(sigTT ? [l:R](Un_cv [N:nat](SP fn N x) l)). +Intro cv; Cut ((n:nat)(continuity (fn n))). +Intro; Cut (continuity (SFL fn cv)). +Intro; Unfold continuity in H1. +Assert H2 := (H1 R0). +Unfold continuity_pt in H2; Unfold continue_in in H2; Unfold limit1_in in H2; Unfold limit_in in H2; Simpl in H2; Unfold R_dist in H2. +Elim (H2 ? H); Intros alp H3. +Elim H3; Intros. +Exists (mkposreal ? H4); Intros. +Rewrite Rplus_Ol; Rewrite exp_0. +Replace ``((exp h)-1)/h`` with (SFL fn cv h). +Replace R1 with (SFL fn cv R0). +Apply H5. +Split. +Unfold D_x no_cond; Split. +Trivial. +Apply (not_sym ? ? H6). +Rewrite minus_R0; Apply H7. +Unfold SFL. +Case (cv ``0``); Intros. +EApply UL_suite. +Apply u. +Unfold Un_cv SP. +Intros; Exists (1); Intros. +Unfold R_dist; Rewrite decomp_sum. +Rewrite (Rplus_sym (fn O R0)). +Replace (fn O R0) with R1. +Unfold Rminus; Rewrite Rplus_assoc; Rewrite Rplus_Ropp_r; Rewrite Rplus_Or. +Replace (sum_f_R0 [i:nat](fn (S i) ``0``) (pred n)) with R0. +Rewrite Rabsolu_R0; Apply H8. +Symmetry; Apply sum_eq_R0; Intros. +Unfold fn. +Simpl. +Unfold Rdiv; Do 2 Rewrite Rmult_Ol; Reflexivity. +Unfold fn; Simpl. +Unfold Rdiv; Rewrite Rinv_R1; Rewrite Rmult_1r; Reflexivity. +Apply lt_le_trans with (1); [Apply lt_n_Sn | Apply H9]. +Unfold SFL exp. +Unfold projT1. +Case (cv h); Case (exist_exp h); Intros. +EApply UL_suite. +Apply u. +Unfold Un_cv; Intros. +Unfold exp_in in e. +Unfold infinit_sum in e. +Cut ``00``. +Intro; Apply Alembert_general. +Intro; Apply Rabsolu_no_R0. +Unfold Rdiv; Apply prod_neq_R0. +Apply pow_nonzero; Assumption. +Apply Rinv_neq_R0; Apply INR_fact_neq_0. +Unfold Un_cv in H0. +Unfold Un_cv; Intros. +Cut ``0