diff options
Diffstat (limited to 'theories7/Reals/Ranalysis1.v')
| -rw-r--r-- | theories7/Reals/Ranalysis1.v | 1046 |
1 files changed, 0 insertions, 1046 deletions
diff --git a/theories7/Reals/Ranalysis1.v b/theories7/Reals/Ranalysis1.v deleted file mode 100644 index 8cb4c358..00000000 --- a/theories7/Reals/Ranalysis1.v +++ /dev/null @@ -1,1046 +0,0 @@ -(************************************************************************) -(* 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 *) -(************************************************************************) - -(*i $Id: Ranalysis1.v,v 1.1.2.1 2004/07/16 19:31:33 herbelin Exp $ i*) - -Require Rbase. -Require Rfunctions. -Require Export Rlimit. -Require Export Rderiv. -V7only [Import R_scope.]. Open Local Scope R_scope. -Implicit Variable Type f:R->R. - -(****************************************************) -(** Basic operations on functions *) -(****************************************************) -Definition plus_fct [f1,f2:R->R] : R->R := [x:R] ``(f1 x)+(f2 x)``. -Definition opp_fct [f:R->R] : R->R := [x:R] ``-(f x)``. -Definition mult_fct [f1,f2:R->R] : R->R := [x:R] ``(f1 x)*(f2 x)``. -Definition mult_real_fct [a:R;f:R->R] : R->R := [x:R] ``a*(f x)``. -Definition minus_fct [f1,f2:R->R] : R->R := [x:R] ``(f1 x)-(f2 x)``. -Definition div_fct [f1,f2:R->R] : R->R := [x:R] ``(f1 x)/(f2 x)``. -Definition div_real_fct [a:R;f:R->R] : R->R := [x:R] ``a/(f x)``. -Definition comp [f1,f2:R->R] : R->R := [x:R] ``(f1 (f2 x))``. -Definition inv_fct [f:R->R] : R->R := [x:R]``/(f x)``. - -V8Infix "+" plus_fct : Rfun_scope. -V8Notation "- x" := (opp_fct x) : Rfun_scope. -V8Infix "*" mult_fct : Rfun_scope. -V8Infix "-" minus_fct : Rfun_scope. -V8Infix "/" div_fct : Rfun_scope. -Notation Local "f1 'o' f2" := (comp f1 f2) (at level 2, right associativity) - : Rfun_scope - V8only (at level 20, right associativity). -V8Notation "/ x" := (inv_fct x) : Rfun_scope. - -Delimits Scope Rfun_scope with F. - -Definition fct_cte [a:R] : R->R := [x:R]a. -Definition id := [x:R]x. - -(****************************************************) -(** Variations of functions *) -(****************************************************) -Definition increasing [f:R->R] : Prop := (x,y:R) ``x<=y``->``(f x)<=(f y)``. -Definition decreasing [f:R->R] : Prop := (x,y:R) ``x<=y``->``(f y)<=(f x)``. -Definition strict_increasing [f:R->R] : Prop := (x,y:R) ``x<y``->``(f x)<(f y)``. -Definition strict_decreasing [f:R->R] : Prop := (x,y:R) ``x<y``->``(f y)<(f x)``. -Definition constant [f:R->R] : Prop := (x,y:R) ``(f x)==(f y)``. - -(**********) -Definition no_cond : R->Prop := [x:R] True. - -(**********) -Definition constant_D_eq [f:R->R;D:R->Prop;c:R] : Prop := (x:R) (D x) -> (f x)==c. - -(***************************************************) -(** Definition of continuity as a limit *) -(***************************************************) - -(**********) -Definition continuity_pt [f:R->R; x0:R] : Prop := (continue_in f no_cond x0). -Definition continuity [f:R->R] : Prop := (x:R) (continuity_pt f x). - -Arguments Scope continuity_pt [Rfun_scope R_scope]. -Arguments Scope continuity [Rfun_scope]. - -(**********) -Lemma continuity_pt_plus : (f1,f2:R->R; x0:R) (continuity_pt f1 x0) -> (continuity_pt f2 x0) -> (continuity_pt (plus_fct f1 f2) x0). -Unfold continuity_pt plus_fct; Unfold continue_in; Intros; Apply limit_plus; Assumption. -Qed. - -Lemma continuity_pt_opp : (f:R->R; x0:R) (continuity_pt f x0) -> (continuity_pt (opp_fct f) x0). -Unfold continuity_pt opp_fct; Unfold continue_in; Intros; Apply limit_Ropp; Assumption. -Qed. - -Lemma continuity_pt_minus : (f1,f2:R->R; x0:R) (continuity_pt f1 x0) -> (continuity_pt f2 x0) -> (continuity_pt (minus_fct f1 f2) x0). -Unfold continuity_pt minus_fct; Unfold continue_in; Intros; Apply limit_minus; Assumption. -Qed. - -Lemma continuity_pt_mult : (f1,f2:R->R; x0:R) (continuity_pt f1 x0) -> (continuity_pt f2 x0) -> (continuity_pt (mult_fct f1 f2) x0). -Unfold continuity_pt mult_fct; Unfold continue_in; Intros; Apply limit_mul; Assumption. -Qed. - -Lemma continuity_pt_const : (f:R->R; x0:R) (constant f) -> (continuity_pt f x0). -Unfold constant continuity_pt; Unfold continue_in; Unfold limit1_in; Unfold limit_in; Intros; Exists ``1``; Split; [Apply Rlt_R0_R1 | Intros; Generalize (H x x0); Intro; Rewrite H2; Simpl; Rewrite R_dist_eq; Assumption]. -Qed. - -Lemma continuity_pt_scal : (f:R->R;a:R; x0:R) (continuity_pt f x0) -> (continuity_pt (mult_real_fct a f) x0). -Unfold continuity_pt mult_real_fct; Unfold continue_in; Intros; Apply (limit_mul ([x:R] a) f (D_x no_cond x0) a (f x0) x0). -Unfold limit1_in; Unfold limit_in; Intros; Exists ``1``; Split. -Apply Rlt_R0_R1. -Intros; Rewrite R_dist_eq; Assumption. -Assumption. -Qed. - -Lemma continuity_pt_inv : (f:R->R; x0:R) (continuity_pt f x0) -> ~``(f x0)==0`` -> (continuity_pt (inv_fct f) x0). -Intros. -Replace (inv_fct f) with [x:R]``/(f x)``. -Unfold continuity_pt; Unfold continue_in; Intros; Apply limit_inv; Assumption. -Unfold inv_fct; Reflexivity. -Qed. - -Lemma div_eq_inv : (f1,f2:R->R) (div_fct f1 f2)==(mult_fct f1 (inv_fct f2)). -Intros; Reflexivity. -Qed. - -Lemma continuity_pt_div : (f1,f2:R->R; x0:R) (continuity_pt f1 x0) -> (continuity_pt f2 x0) -> ~``(f2 x0)==0`` -> (continuity_pt (div_fct f1 f2) x0). -Intros; Rewrite -> (div_eq_inv f1 f2); Apply continuity_pt_mult; [Assumption | Apply continuity_pt_inv; Assumption]. -Qed. - -Lemma continuity_pt_comp : (f1,f2:R->R;x:R) (continuity_pt f1 x) -> (continuity_pt f2 (f1 x)) -> (continuity_pt (comp f2 f1) x). -Unfold continuity_pt; Unfold continue_in; Intros; Unfold comp. -Cut (limit1_in [x0:R](f2 (f1 x0)) (Dgf (D_x no_cond x) (D_x no_cond (f1 x)) f1) -(f2 (f1 x)) x) -> (limit1_in [x0:R](f2 (f1 x0)) (D_x no_cond x) (f2 (f1 x)) x). -Intro; Apply H1. -EApply limit_comp. -Apply H. -Apply H0. -Unfold limit1_in; Unfold limit_in; Unfold dist; Simpl; Unfold R_dist; Intros. -Assert H3 := (H1 eps H2). -Elim H3; Intros. -Exists x0. -Split. -Elim H4; Intros; Assumption. -Intros; Case (Req_EM (f1 x) (f1 x1)); Intro. -Rewrite H6; Unfold Rminus; Rewrite Rplus_Ropp_r; Rewrite Rabsolu_R0; Assumption. -Elim H4; Intros; Apply H8. -Split. -Unfold Dgf D_x no_cond. -Split. -Split. -Trivial. -Elim H5; Unfold D_x no_cond; Intros. -Elim H9; Intros; Assumption. -Split. -Trivial. -Assumption. -Elim H5; Intros; Assumption. -Qed. - -(**********) -Lemma continuity_plus : (f1,f2:R->R) (continuity f1)->(continuity f2)->(continuity (plus_fct f1 f2)). -Unfold continuity; Intros; Apply (continuity_pt_plus f1 f2 x (H x) (H0 x)). -Qed. - -Lemma continuity_opp : (f:R->R) (continuity f)->(continuity (opp_fct f)). -Unfold continuity; Intros; Apply (continuity_pt_opp f x (H x)). -Qed. - -Lemma continuity_minus : (f1,f2:R->R) (continuity f1)->(continuity f2)->(continuity (minus_fct f1 f2)). -Unfold continuity; Intros; Apply (continuity_pt_minus f1 f2 x (H x) (H0 x)). -Qed. - -Lemma continuity_mult : (f1,f2:R->R) (continuity f1)->(continuity f2)->(continuity (mult_fct f1 f2)). -Unfold continuity; Intros; Apply (continuity_pt_mult f1 f2 x (H x) (H0 x)). -Qed. - -Lemma continuity_const : (f:R->R) (constant f) -> (continuity f). -Unfold continuity; Intros; Apply (continuity_pt_const f x H). -Qed. - -Lemma continuity_scal : (f:R->R;a:R) (continuity f) -> (continuity (mult_real_fct a f)). -Unfold continuity; Intros; Apply (continuity_pt_scal f a x (H x)). -Qed. - -Lemma continuity_inv : (f:R->R) (continuity f)->((x:R) ~``(f x)==0``)->(continuity (inv_fct f)). -Unfold continuity; Intros; Apply (continuity_pt_inv f x (H x) (H0 x)). -Qed. - -Lemma continuity_div : (f1,f2:R->R) (continuity f1)->(continuity f2)->((x:R) ~``(f2 x)==0``)->(continuity (div_fct f1 f2)). -Unfold continuity; Intros; Apply (continuity_pt_div f1 f2 x (H x) (H0 x) (H1 x)). -Qed. - -Lemma continuity_comp : (f1,f2:R->R) (continuity f1) -> (continuity f2) -> (continuity (comp f2 f1)). -Unfold continuity; Intros. -Apply (continuity_pt_comp f1 f2 x (H x) (H0 (f1 x))). -Qed. - - -(*****************************************************) -(** Derivative's definition using Landau's kernel *) -(*****************************************************) - -Definition derivable_pt_lim [f:R->R;x,l:R] : Prop := ((eps:R) ``0<eps``->(EXT delta : posreal | ((h:R) ~``h==0``->``(Rabsolu h)<delta`` -> ``(Rabsolu ((((f (x+h))-(f x))/h)-l))<eps``))). - -Definition derivable_pt_abs [f:R->R;x:R] : R -> Prop := [l:R](derivable_pt_lim f x l). - -Definition derivable_pt [f:R->R;x:R] := (SigT R (derivable_pt_abs f x)). -Definition derivable [f:R->R] := (x:R)(derivable_pt f x). - -Definition derive_pt [f:R->R;x:R;pr:(derivable_pt f x)] := (projT1 ? ? pr). -Definition derive [f:R->R;pr:(derivable f)] := [x:R](derive_pt f x (pr x)). - -Arguments Scope derivable_pt_lim [Rfun_scope R_scope]. -Arguments Scope derivable_pt_abs [Rfun_scope R_scope R_scope]. -Arguments Scope derivable_pt [Rfun_scope R_scope]. -Arguments Scope derivable [Rfun_scope]. -Arguments Scope derive_pt [Rfun_scope R_scope _]. -Arguments Scope derive [Rfun_scope _]. - -Definition antiderivative [f,g:R->R;a,b:R] : Prop := ((x:R)``a<=x<=b``->(EXT pr : (derivable_pt g x) | (f x)==(derive_pt g x pr)))/\``a<=b``. -(************************************) -(** Class of differential functions *) -(************************************) -Record Differential : Type := mkDifferential { -d1 :> R->R; -cond_diff : (derivable d1) }. - -Record Differential_D2 : Type := mkDifferential_D2 { -d2 :> R->R; -cond_D1 : (derivable d2); -cond_D2 : (derivable (derive d2 cond_D1)) }. - -(**********) -Lemma unicite_step1 : (f:R->R;x,l1,l2:R) (limit1_in [h:R]``((f (x+h))-(f x))/h`` [h:R]``h<>0`` l1 R0) -> (limit1_in [h:R]``((f (x+h))-(f x))/h`` [h:R]``h<>0`` l2 R0) -> l1 == l2. -Intros; Apply (single_limit [h:R]``((f (x+h))-(f x))/h`` [h:R]``h<>0`` l1 l2 R0); Try Assumption. -Unfold adhDa; Intros; Exists ``alp/2``. -Split. -Unfold Rdiv; Apply prod_neq_R0. -Red; Intro; Rewrite H2 in H1; Elim (Rlt_antirefl ? H1). -Apply Rinv_neq_R0; DiscrR. -Unfold R_dist; Unfold Rminus; Rewrite Ropp_O; Rewrite Rplus_Or; Unfold Rdiv; Rewrite Rabsolu_mult. -Replace ``(Rabsolu (/2))`` with ``/2``. -Replace (Rabsolu alp) with alp. -Apply Rlt_monotony_contra with ``2``. -Sup0. -Rewrite (Rmult_sym ``2``); Rewrite Rmult_assoc; Rewrite <- Rinv_l_sym; [Idtac | DiscrR]; Rewrite Rmult_1r; Rewrite double; Pattern 1 alp; Replace alp with ``alp+0``; [Idtac | Ring]; Apply Rlt_compatibility; Assumption. -Symmetry; Apply Rabsolu_right; Left; Assumption. -Symmetry; Apply Rabsolu_right; Left; Change ``0</2``; Apply Rlt_Rinv; Sup0. -Qed. - -Lemma unicite_step2 : (f:R->R;x,l:R) (derivable_pt_lim f x l) -> (limit1_in [h:R]``((f (x+h))-(f x))/h`` [h:R]``h<>0`` l R0). -Unfold derivable_pt_lim; Intros; Unfold limit1_in; Unfold limit_in; Intros. -Assert H1 := (H eps H0). -Elim H1 ; Intros. -Exists (pos x0). -Split. -Apply (cond_pos x0). -Simpl; Unfold R_dist; Intros. -Elim H3; Intros. -Apply H2; [Assumption |Unfold Rminus in H5; Rewrite Ropp_O in H5; Rewrite Rplus_Or in H5; Assumption]. -Qed. - -Lemma unicite_step3 : (f:R->R;x,l:R) (limit1_in [h:R]``((f (x+h))-(f x))/h`` [h:R]``h<>0`` l R0) -> (derivable_pt_lim f x l). -Unfold limit1_in derivable_pt_lim; Unfold limit_in; Unfold dist; Simpl; Intros. -Elim (H eps H0). -Intros; Elim H1; Intros. -Exists (mkposreal x0 H2). -Simpl; Intros; Unfold R_dist in H3; Apply (H3 h). -Split; [Assumption | Unfold Rminus; Rewrite Ropp_O; Rewrite Rplus_Or; Assumption]. -Qed. - -Lemma unicite_limite : (f:R->R;x,l1,l2:R) (derivable_pt_lim f x l1) -> (derivable_pt_lim f x l2) -> l1==l2. -Intros. -Assert H1 := (unicite_step2 ? ? ? H). -Assert H2 := (unicite_step2 ? ? ? H0). -Assert H3 := (unicite_step1 ? ? ? ? H1 H2). -Assumption. -Qed. - -Lemma derive_pt_eq : (f:R->R;x,l:R;pr:(derivable_pt f x)) (derive_pt f x pr)==l <-> (derivable_pt_lim f x l). -Intros; Split. -Intro; Assert H1 := (projT2 ? ? pr); Unfold derive_pt in H; Rewrite H in H1; Assumption. -Intro; Assert H1 := (projT2 ? ? pr); Unfold derivable_pt_abs in H1. -Assert H2 := (unicite_limite ? ? ? ? H H1). -Unfold derive_pt; Unfold derivable_pt_abs. -Symmetry; Assumption. -Qed. - -(**********) -Lemma derive_pt_eq_0 : (f:R->R;x,l:R;pr:(derivable_pt f x)) (derivable_pt_lim f x l) -> (derive_pt f x pr)==l. -Intros; Elim (derive_pt_eq f x l pr); Intros. -Apply (H1 H). -Qed. - -(**********) -Lemma derive_pt_eq_1 : (f:R->R;x,l:R;pr:(derivable_pt f x)) (derive_pt f x pr)==l -> (derivable_pt_lim f x l). -Intros; Elim (derive_pt_eq f x l pr); Intros. -Apply (H0 H). -Qed. - - -(********************************************************************) -(** Equivalence of this definition with the one using limit concept *) -(********************************************************************) -Lemma derive_pt_D_in : (f,df:R->R;x:R;pr:(derivable_pt f x)) (D_in f df no_cond x) <-> (derive_pt f x pr)==(df x). -Intros; Split. -Unfold D_in; Unfold limit1_in; Unfold limit_in; Simpl; Unfold R_dist; Intros. -Apply derive_pt_eq_0. -Unfold derivable_pt_lim. -Intros; Elim (H eps H0); Intros alpha H1; Elim H1; Intros; Exists (mkposreal alpha H2); Intros; Generalize (H3 ``x+h``); Intro; Cut ``x+h-x==h``; [Intro; Cut ``(D_x no_cond x (x+h))``/\``(Rabsolu (x+h-x)) < alpha``; [Intro; Generalize (H6 H8); Rewrite H7; Intro; Assumption | Split; [Unfold D_x; Split; [Unfold no_cond; Trivial | Apply Rminus_not_eq_right; Rewrite H7; Assumption] | Rewrite H7; Assumption]] | Ring]. -Intro. -Assert H0 := (derive_pt_eq_1 f x (df x) pr H). -Unfold D_in; Unfold limit1_in; Unfold limit_in; Unfold dist; Simpl; Unfold R_dist; Intros. -Elim (H0 eps H1); Intros alpha H2; Exists (pos alpha); Split. -Apply (cond_pos alpha). -Intros; Elim H3; Intros; Unfold D_x in H4; Elim H4; Intros; Cut ``x0-x<>0``. -Intro; Generalize (H2 ``x0-x`` H8 H5); Replace ``x+(x0-x)`` with x0. -Intro; Assumption. -Ring. -Auto with real. -Qed. - -Lemma derivable_pt_lim_D_in : (f,df:R->R;x:R) (D_in f df no_cond x) <-> (derivable_pt_lim f x (df x)). -Intros; Split. -Unfold D_in; Unfold limit1_in; Unfold limit_in; Simpl; Unfold R_dist; Intros. -Unfold derivable_pt_lim. -Intros; Elim (H eps H0); Intros alpha H1; Elim H1; Intros; Exists (mkposreal alpha H2); Intros; Generalize (H3 ``x+h``); Intro; Cut ``x+h-x==h``; [Intro; Cut ``(D_x no_cond x (x+h))``/\``(Rabsolu (x+h-x)) < alpha``; [Intro; Generalize (H6 H8); Rewrite H7; Intro; Assumption | Split; [Unfold D_x; Split; [Unfold no_cond; Trivial | Apply Rminus_not_eq_right; Rewrite H7; Assumption] | Rewrite H7; Assumption]] | Ring]. -Intro. -Unfold derivable_pt_lim in H. -Unfold D_in; Unfold limit1_in; Unfold limit_in; Unfold dist; Simpl; Unfold R_dist; Intros. -Elim (H eps H0); Intros alpha H2; Exists (pos alpha); Split. -Apply (cond_pos alpha). -Intros. -Elim H1; Intros; Unfold D_x in H3; Elim H3; Intros; Cut ``x0-x<>0``. -Intro; Generalize (H2 ``x0-x`` H7 H4); Replace ``x+(x0-x)`` with x0. -Intro; Assumption. -Ring. -Auto with real. -Qed. - - -(***********************************) -(** derivability -> continuity *) -(***********************************) -(**********) -Lemma derivable_derive : (f:R->R;x:R;pr:(derivable_pt f x)) (EXT l : R | (derive_pt f x pr)==l). -Intros; Exists (projT1 ? ? pr). -Unfold derive_pt; Reflexivity. -Qed. - -Theorem derivable_continuous_pt : (f:R->R;x:R) (derivable_pt f x) -> (continuity_pt f x). -Intros. -Generalize (derivable_derive f x X); Intro. -Elim H; Intros l H1. -Cut l==((fct_cte l) x). -Intro. -Rewrite H0 in H1. -Generalize (derive_pt_D_in f (fct_cte l) x); Intro. -Elim (H2 X); Intros. -Generalize (H4 H1); Intro. -Unfold continuity_pt. -Apply (cont_deriv f (fct_cte l) no_cond x H5). -Unfold fct_cte; Reflexivity. -Qed. - -Theorem derivable_continuous : (f:R->R) (derivable f) -> (continuity f). -Unfold derivable continuity; Intros. -Apply (derivable_continuous_pt f x (X x)). -Qed. - -(****************************************************************) -(** Main rules *) -(****************************************************************) - -Lemma derivable_pt_lim_plus : (f1,f2:R->R;x,l1,l2:R) (derivable_pt_lim f1 x l1) -> (derivable_pt_lim f2 x l2) -> (derivable_pt_lim (plus_fct f1 f2) x ``l1+l2``). -Intros. -Apply unicite_step3. -Assert H1 := (unicite_step2 ? ? ? H). -Assert H2 := (unicite_step2 ? ? ? H0). -Unfold plus_fct. -Cut (h:R)``((f1 (x+h))+(f2 (x+h))-((f1 x)+(f2 x)))/h``==``((f1 (x+h))-(f1 x))/h+((f2 (x+h))-(f2 x))/h``. -Intro. -Generalize(limit_plus [h':R]``((f1 (x+h'))-(f1 x))/h'`` [h':R]``((f2 (x+h'))-(f2 x))/h'`` [h:R]``h <> 0`` l1 l2 ``0`` H1 H2). -Unfold limit1_in; Unfold limit_in; Unfold dist; Simpl; Unfold R_dist; Intros. -Elim (H4 eps H5); Intros. -Exists x0. -Elim H6; Intros. -Split. -Assumption. -Intros; Rewrite H3; Apply H8; Assumption. -Intro; Unfold Rdiv; Ring. -Qed. - -Lemma derivable_pt_lim_opp : (f:R->R;x,l:R) (derivable_pt_lim f x l) -> (derivable_pt_lim (opp_fct f) x (Ropp l)). -Intros. -Apply unicite_step3. -Assert H1 := (unicite_step2 ? ? ? H). -Unfold opp_fct. -Cut (h:R) ``( -(f (x+h))- -(f x))/h``==(Ropp ``((f (x+h))-(f x))/h``). -Intro. -Generalize (limit_Ropp [h:R]``((f (x+h))-(f x))/h``[h:R]``h <> 0`` l ``0`` H1). -Unfold limit1_in; Unfold limit_in; Unfold dist; Simpl; Unfold R_dist; Intros. -Elim (H2 eps H3); Intros. -Exists x0. -Elim H4; Intros. -Split. -Assumption. -Intros; Rewrite H0; Apply H6; Assumption. -Intro; Unfold Rdiv; Ring. -Qed. - -Lemma derivable_pt_lim_minus : (f1,f2:R->R;x,l1,l2:R) (derivable_pt_lim f1 x l1) -> (derivable_pt_lim f2 x l2) -> (derivable_pt_lim (minus_fct f1 f2) x ``l1-l2``). -Intros. -Apply unicite_step3. -Assert H1 := (unicite_step2 ? ? ? H). -Assert H2 := (unicite_step2 ? ? ? H0). -Unfold minus_fct. -Cut (h:R)``((f1 (x+h))-(f1 x))/h-((f2 (x+h))-(f2 x))/h``==``((f1 (x+h))-(f2 (x+h))-((f1 x)-(f2 x)))/h``. -Intro. -Generalize (limit_minus [h':R]``((f1 (x+h'))-(f1 x))/h'`` [h':R]``((f2 (x+h'))-(f2 x))/h'`` [h:R]``h <> 0`` l1 l2 ``0`` H1 H2). -Unfold limit1_in; Unfold limit_in; Unfold dist; Simpl; Unfold R_dist; Intros. -Elim (H4 eps H5); Intros. -Exists x0. -Elim H6; Intros. -Split. -Assumption. -Intros; Rewrite <- H3; Apply H8; Assumption. -Intro; Unfold Rdiv; Ring. -Qed. - -Lemma derivable_pt_lim_mult : (f1,f2:R->R;x,l1,l2:R) (derivable_pt_lim f1 x l1) -> (derivable_pt_lim f2 x l2) -> (derivable_pt_lim (mult_fct f1 f2) x ``l1*(f2 x)+(f1 x)*l2``). -Intros. -Assert H1 := (derivable_pt_lim_D_in f1 [y:R]l1 x). -Elim H1; Intros. -Assert H4 := (H3 H). -Assert H5 := (derivable_pt_lim_D_in f2 [y:R]l2 x). -Elim H5; Intros. -Assert H8 := (H7 H0). -Clear H1 H2 H3 H5 H6 H7. -Assert H1 := (derivable_pt_lim_D_in (mult_fct f1 f2) [y:R]``l1*(f2 x)+(f1 x)*l2`` x). -Elim H1; Intros. -Clear H1 H3. -Apply H2. -Unfold mult_fct. -Apply (Dmult no_cond [y:R]l1 [y:R]l2 f1 f2 x); Assumption. -Qed. - -Lemma derivable_pt_lim_const : (a,x:R) (derivable_pt_lim (fct_cte a) x ``0``). -Intros; Unfold fct_cte derivable_pt_lim. -Intros; Exists (mkposreal ``1`` Rlt_R0_R1); Intros; Unfold Rminus; Rewrite Rplus_Ropp_r; Unfold Rdiv; Rewrite Rmult_Ol; Rewrite Rplus_Ropp_r; Rewrite Rabsolu_R0; Assumption. -Qed. - -Lemma derivable_pt_lim_scal : (f:R->R;a,x,l:R) (derivable_pt_lim f x l) -> (derivable_pt_lim (mult_real_fct a f) x ``a*l``). -Intros. -Assert H0 := (derivable_pt_lim_const a x). -Replace (mult_real_fct a f) with (mult_fct (fct_cte a) f). -Replace ``a*l`` with ``0*(f x)+a*l``; [Idtac | Ring]. -Apply (derivable_pt_lim_mult (fct_cte a) f x ``0`` l); Assumption. -Unfold mult_real_fct mult_fct fct_cte; Reflexivity. -Qed. - -Lemma derivable_pt_lim_id : (x:R) (derivable_pt_lim id x ``1``). -Intro; Unfold derivable_pt_lim. -Intros eps Heps; Exists (mkposreal eps Heps); Intros h H1 H2; Unfold id; Replace ``(x+h-x)/h-1`` with ``0``. -Rewrite Rabsolu_R0; Apply Rle_lt_trans with ``(Rabsolu h)``. -Apply Rabsolu_pos. -Assumption. -Unfold Rminus; Rewrite Rplus_assoc; Rewrite (Rplus_sym x); Rewrite Rplus_assoc. -Rewrite Rplus_Ropp_l; Rewrite Rplus_Or; Unfold Rdiv; Rewrite <- Rinv_r_sym. -Symmetry; Apply Rplus_Ropp_r. -Assumption. -Qed. - -Lemma derivable_pt_lim_Rsqr : (x:R) (derivable_pt_lim Rsqr x ``2*x``). -Intro; Unfold derivable_pt_lim. -Unfold Rsqr; Intros eps Heps; Exists (mkposreal eps Heps); Intros h H1 H2; Replace ``((x+h)*(x+h)-x*x)/h-2*x`` with ``h``. -Assumption. -Replace ``(x+h)*(x+h)-x*x`` with ``2*x*h+h*h``; [Idtac | Ring]. -Unfold Rdiv; Rewrite Rmult_Rplus_distrl. -Repeat Rewrite Rmult_assoc. -Repeat Rewrite <- Rinv_r_sym; [Idtac | Assumption]. -Ring. -Qed. - -Lemma derivable_pt_lim_comp : (f1,f2:R->R;x,l1,l2:R) (derivable_pt_lim f1 x l1) -> (derivable_pt_lim f2 (f1 x) l2) -> (derivable_pt_lim (comp f2 f1) x ``l2*l1``). -Intros; Assert H1 := (derivable_pt_lim_D_in f1 [y:R]l1 x). -Elim H1; Intros. -Assert H4 := (H3 H). -Assert H5 := (derivable_pt_lim_D_in f2 [y:R]l2 (f1 x)). -Elim H5; Intros. -Assert H8 := (H7 H0). -Clear H1 H2 H3 H5 H6 H7. -Assert H1 := (derivable_pt_lim_D_in (comp f2 f1) [y:R]``l2*l1`` x). -Elim H1; Intros. -Clear H1 H3; Apply H2. -Unfold comp; Cut (D_in [x0:R](f2 (f1 x0)) [y:R]``l2*l1`` (Dgf no_cond no_cond f1) x) -> (D_in [x0:R](f2 (f1 x0)) [y:R]``l2*l1`` no_cond x). -Intro; Apply H1. -Rewrite Rmult_sym; Apply (Dcomp no_cond no_cond [y:R]l1 [y:R]l2 f1 f2 x); Assumption. -Unfold Dgf D_in no_cond; Unfold limit1_in; Unfold limit_in; Unfold dist; Simpl; Unfold R_dist; Intros. -Elim (H1 eps H3); Intros. -Exists x0; Intros; Split. -Elim H5; Intros; Assumption. -Intros; Elim H5; Intros; Apply H9; Split. -Unfold D_x; Split. -Split; Trivial. -Elim H6; Intros; Unfold D_x in H10; Elim H10; Intros; Assumption. -Elim H6; Intros; Assumption. -Qed. - -Lemma derivable_pt_plus : (f1,f2:R->R;x:R) (derivable_pt f1 x) -> (derivable_pt f2 x) -> (derivable_pt (plus_fct f1 f2) x). -Unfold derivable_pt; Intros. -Elim X; Intros. -Elim X0; Intros. -Apply Specif.existT with ``x0+x1``. -Apply derivable_pt_lim_plus; Assumption. -Qed. - -Lemma derivable_pt_opp : (f:R->R;x:R) (derivable_pt f x) -> (derivable_pt (opp_fct f) x). -Unfold derivable_pt; Intros. -Elim X; Intros. -Apply Specif.existT with ``-x0``. -Apply derivable_pt_lim_opp; Assumption. -Qed. - -Lemma derivable_pt_minus : (f1,f2:R->R;x:R) (derivable_pt f1 x) -> (derivable_pt f2 x) -> (derivable_pt (minus_fct f1 f2) x). -Unfold derivable_pt; Intros. -Elim X; Intros. -Elim X0; Intros. -Apply Specif.existT with ``x0-x1``. -Apply derivable_pt_lim_minus; Assumption. -Qed. - -Lemma derivable_pt_mult : (f1,f2:R->R;x:R) (derivable_pt f1 x) -> (derivable_pt f2 x) -> (derivable_pt (mult_fct f1 f2) x). -Unfold derivable_pt; Intros. -Elim X; Intros. -Elim X0; Intros. -Apply Specif.existT with ``x0*(f2 x)+(f1 x)*x1``. -Apply derivable_pt_lim_mult; Assumption. -Qed. - -Lemma derivable_pt_const : (a,x:R) (derivable_pt (fct_cte a) x). -Intros; Unfold derivable_pt. -Apply Specif.existT with ``0``. -Apply derivable_pt_lim_const. -Qed. - -Lemma derivable_pt_scal : (f:R->R;a,x:R) (derivable_pt f x) -> (derivable_pt (mult_real_fct a f) x). -Unfold derivable_pt; Intros. -Elim X; Intros. -Apply Specif.existT with ``a*x0``. -Apply derivable_pt_lim_scal; Assumption. -Qed. - -Lemma derivable_pt_id : (x:R) (derivable_pt id x). -Unfold derivable_pt; Intro. -Exists ``1``. -Apply derivable_pt_lim_id. -Qed. - -Lemma derivable_pt_Rsqr : (x:R) (derivable_pt Rsqr x). -Unfold derivable_pt; Intro; Apply Specif.existT with ``2*x``. -Apply derivable_pt_lim_Rsqr. -Qed. - -Lemma derivable_pt_comp : (f1,f2:R->R;x:R) (derivable_pt f1 x) -> (derivable_pt f2 (f1 x)) -> (derivable_pt (comp f2 f1) x). -Unfold derivable_pt; Intros. -Elim X; Intros. -Elim X0 ;Intros. -Apply Specif.existT with ``x1*x0``. -Apply derivable_pt_lim_comp; Assumption. -Qed. - -Lemma derivable_plus : (f1,f2:R->R) (derivable f1) -> (derivable f2) -> (derivable (plus_fct f1 f2)). -Unfold derivable; Intros. -Apply (derivable_pt_plus ? ? x (X ?) (X0 ?)). -Qed. - -Lemma derivable_opp : (f:R->R) (derivable f) -> (derivable (opp_fct f)). -Unfold derivable; Intros. -Apply (derivable_pt_opp ? x (X ?)). -Qed. - -Lemma derivable_minus : (f1,f2:R->R) (derivable f1) -> (derivable f2) -> (derivable (minus_fct f1 f2)). -Unfold derivable; Intros. -Apply (derivable_pt_minus ? ? x (X ?) (X0 ?)). -Qed. - -Lemma derivable_mult : (f1,f2:R->R) (derivable f1) -> (derivable f2) -> (derivable (mult_fct f1 f2)). -Unfold derivable; Intros. -Apply (derivable_pt_mult ? ? x (X ?) (X0 ?)). -Qed. - -Lemma derivable_const : (a:R) (derivable (fct_cte a)). -Unfold derivable; Intros. -Apply derivable_pt_const. -Qed. - -Lemma derivable_scal : (f:R->R;a:R) (derivable f) -> (derivable (mult_real_fct a f)). -Unfold derivable; Intros. -Apply (derivable_pt_scal ? a x (X ?)). -Qed. - -Lemma derivable_id : (derivable id). -Unfold derivable; Intro; Apply derivable_pt_id. -Qed. - -Lemma derivable_Rsqr : (derivable Rsqr). -Unfold derivable; Intro; Apply derivable_pt_Rsqr. -Qed. - -Lemma derivable_comp : (f1,f2:R->R) (derivable f1) -> (derivable f2) -> (derivable (comp f2 f1)). -Unfold derivable; Intros. -Apply (derivable_pt_comp ? ? x (X ?) (X0 ?)). -Qed. - -Lemma derive_pt_plus : (f1,f2:R->R;x:R;pr1:(derivable_pt f1 x);pr2:(derivable_pt f2 x)) ``(derive_pt (plus_fct f1 f2) x (derivable_pt_plus ? ? ? pr1 pr2)) == (derive_pt f1 x pr1) + (derive_pt f2 x pr2)``. -Intros. -Assert H := (derivable_derive f1 x pr1). -Assert H0 := (derivable_derive f2 x pr2). -Assert H1 := (derivable_derive (plus_fct f1 f2) x (derivable_pt_plus ? ? ? pr1 pr2)). -Elim H; Clear H; Intros l1 H. -Elim H0; Clear H0; Intros l2 H0. -Elim H1; Clear H1; Intros l H1. -Rewrite H; Rewrite H0; Apply derive_pt_eq_0. -Assert H3 := (projT2 ? ? pr1). -Unfold derive_pt in H; Rewrite H in H3. -Assert H4 := (projT2 ? ? pr2). -Unfold derive_pt in H0; Rewrite H0 in H4. -Apply derivable_pt_lim_plus; Assumption. -Qed. - -Lemma derive_pt_opp : (f:R->R;x:R;pr1:(derivable_pt f x)) ``(derive_pt (opp_fct f) x (derivable_pt_opp ? ? pr1)) == -(derive_pt f x pr1)``. -Intros. -Assert H := (derivable_derive f x pr1). -Assert H0 := (derivable_derive (opp_fct f) x (derivable_pt_opp ? ? pr1)). -Elim H; Clear H; Intros l1 H. -Elim H0; Clear H0; Intros l2 H0. -Rewrite H; Apply derive_pt_eq_0. -Assert H3 := (projT2 ? ? pr1). -Unfold derive_pt in H; Rewrite H in H3. -Apply derivable_pt_lim_opp; Assumption. -Qed. - -Lemma derive_pt_minus : (f1,f2:R->R;x:R;pr1:(derivable_pt f1 x);pr2:(derivable_pt f2 x)) ``(derive_pt (minus_fct f1 f2) x (derivable_pt_minus ? ? ? pr1 pr2)) == (derive_pt f1 x pr1) - (derive_pt f2 x pr2)``. -Intros. -Assert H := (derivable_derive f1 x pr1). -Assert H0 := (derivable_derive f2 x pr2). -Assert H1 := (derivable_derive (minus_fct f1 f2) x (derivable_pt_minus ? ? ? pr1 pr2)). -Elim H; Clear H; Intros l1 H. -Elim H0; Clear H0; Intros l2 H0. -Elim H1; Clear H1; Intros l H1. -Rewrite H; Rewrite H0; Apply derive_pt_eq_0. -Assert H3 := (projT2 ? ? pr1). -Unfold derive_pt in H; Rewrite H in H3. -Assert H4 := (projT2 ? ? pr2). -Unfold derive_pt in H0; Rewrite H0 in H4. -Apply derivable_pt_lim_minus; Assumption. -Qed. - -Lemma derive_pt_mult : (f1,f2:R->R;x:R;pr1:(derivable_pt f1 x);pr2:(derivable_pt f2 x)) ``(derive_pt (mult_fct f1 f2) x (derivable_pt_mult ? ? ? pr1 pr2)) == (derive_pt f1 x pr1)*(f2 x) + (f1 x)*(derive_pt f2 x pr2)``. -Intros. -Assert H := (derivable_derive f1 x pr1). -Assert H0 := (derivable_derive f2 x pr2). -Assert H1 := (derivable_derive (mult_fct f1 f2) x (derivable_pt_mult ? ? ? pr1 pr2)). -Elim H; Clear H; Intros l1 H. -Elim H0; Clear H0; Intros l2 H0. -Elim H1; Clear H1; Intros l H1. -Rewrite H; Rewrite H0; Apply derive_pt_eq_0. -Assert H3 := (projT2 ? ? pr1). -Unfold derive_pt in H; Rewrite H in H3. -Assert H4 := (projT2 ? ? pr2). -Unfold derive_pt in H0; Rewrite H0 in H4. -Apply derivable_pt_lim_mult; Assumption. -Qed. - -Lemma derive_pt_const : (a,x:R) (derive_pt (fct_cte a) x (derivable_pt_const a x)) == R0. -Intros. -Apply derive_pt_eq_0. -Apply derivable_pt_lim_const. -Qed. - -Lemma derive_pt_scal : (f:R->R;a,x:R;pr:(derivable_pt f x)) ``(derive_pt (mult_real_fct a f) x (derivable_pt_scal ? ? ? pr)) == a * (derive_pt f x pr)``. -Intros. -Assert H := (derivable_derive f x pr). -Assert H0 := (derivable_derive (mult_real_fct a f) x (derivable_pt_scal ? ? ? pr)). -Elim H; Clear H; Intros l1 H. -Elim H0; Clear H0; Intros l2 H0. -Rewrite H; Apply derive_pt_eq_0. -Assert H3 := (projT2 ? ? pr). -Unfold derive_pt in H; Rewrite H in H3. -Apply derivable_pt_lim_scal; Assumption. -Qed. - -Lemma derive_pt_id : (x:R) (derive_pt id x (derivable_pt_id ?))==R1. -Intros. -Apply derive_pt_eq_0. -Apply derivable_pt_lim_id. -Qed. - -Lemma derive_pt_Rsqr : (x:R) (derive_pt Rsqr x (derivable_pt_Rsqr ?)) == ``2*x``. -Intros. -Apply derive_pt_eq_0. -Apply derivable_pt_lim_Rsqr. -Qed. - -Lemma derive_pt_comp : (f1,f2:R->R;x:R;pr1:(derivable_pt f1 x);pr2:(derivable_pt f2 (f1 x))) ``(derive_pt (comp f2 f1) x (derivable_pt_comp ? ? ? pr1 pr2)) == (derive_pt f2 (f1 x) pr2) * (derive_pt f1 x pr1)``. -Intros. -Assert H := (derivable_derive f1 x pr1). -Assert H0 := (derivable_derive f2 (f1 x) pr2). -Assert H1 := (derivable_derive (comp f2 f1) x (derivable_pt_comp ? ? ? pr1 pr2)). -Elim H; Clear H; Intros l1 H. -Elim H0; Clear H0; Intros l2 H0. -Elim H1; Clear H1; Intros l H1. -Rewrite H; Rewrite H0; Apply derive_pt_eq_0. -Assert H3 := (projT2 ? ? pr1). -Unfold derive_pt in H; Rewrite H in H3. -Assert H4 := (projT2 ? ? pr2). -Unfold derive_pt in H0; Rewrite H0 in H4. -Apply derivable_pt_lim_comp; Assumption. -Qed. - -(* Pow *) -Definition pow_fct [n:nat] : R->R := [y:R](pow y n). - -Lemma derivable_pt_lim_pow_pos : (x:R;n:nat) (lt O n) -> (derivable_pt_lim [y:R](pow y n) x ``(INR n)*(pow x (pred n))``). -Intros. -Induction n. -Elim (lt_n_n ? H). -Cut n=O\/(lt O n). -Intro; Elim H0; Intro. -Rewrite H1; Simpl. -Replace [y:R]``y*1`` with (mult_fct id (fct_cte R1)). -Replace ``1*1`` with ``1*(fct_cte R1 x)+(id x)*0``. -Apply derivable_pt_lim_mult. -Apply derivable_pt_lim_id. -Apply derivable_pt_lim_const. -Unfold fct_cte id; Ring. -Reflexivity. -Replace [y:R](pow y (S n)) with [y:R]``y*(pow y n)``. -Replace (pred (S n)) with n; [Idtac | Reflexivity]. -Replace [y:R]``y*(pow y n)`` with (mult_fct id [y:R](pow y n)). -Pose f := [y:R](pow y n). -Replace ``(INR (S n))*(pow x n)`` with (Rplus (Rmult R1 (f x)) (Rmult (id x) (Rmult (INR n) (pow x (pred n))))). -Apply derivable_pt_lim_mult. -Apply derivable_pt_lim_id. -Unfold f; Apply Hrecn; Assumption. -Unfold f. -Pattern 1 5 n; Replace n with (S (pred n)). -Unfold id; Rewrite S_INR; Simpl. -Ring. -Symmetry; Apply S_pred with O; Assumption. -Unfold mult_fct id; Reflexivity. -Reflexivity. -Inversion H. -Left; Reflexivity. -Right. -Apply lt_le_trans with (1). -Apply lt_O_Sn. -Assumption. -Qed. - -Lemma derivable_pt_lim_pow : (x:R; n:nat) (derivable_pt_lim [y:R](pow y n) x ``(INR n)*(pow x (pred n))``). -Intros. -Induction n. -Simpl. -Rewrite Rmult_Ol. -Replace [_:R]``1`` with (fct_cte R1); [Apply derivable_pt_lim_const | Reflexivity]. -Apply derivable_pt_lim_pow_pos. -Apply lt_O_Sn. -Qed. - -Lemma derivable_pt_pow : (n:nat;x:R) (derivable_pt [y:R](pow y n) x). -Intros; Unfold derivable_pt. -Apply Specif.existT with ``(INR n)*(pow x (pred n))``. -Apply derivable_pt_lim_pow. -Qed. - -Lemma derivable_pow : (n:nat) (derivable [y:R](pow y n)). -Intro; Unfold derivable; Intro; Apply derivable_pt_pow. -Qed. - -Lemma derive_pt_pow : (n:nat;x:R) (derive_pt [y:R](pow y n) x (derivable_pt_pow n x))==``(INR n)*(pow x (pred n))``. -Intros; Apply derive_pt_eq_0. -Apply derivable_pt_lim_pow. -Qed. - -Lemma pr_nu : (f:R->R;x:R;pr1,pr2:(derivable_pt f x)) (derive_pt f x pr1)==(derive_pt f x pr2). -Intros. -Unfold derivable_pt in pr1. -Unfold derivable_pt in pr2. -Elim pr1; Intros. -Elim pr2; Intros. -Unfold derivable_pt_abs in p. -Unfold derivable_pt_abs in p0. -Simpl. -Apply (unicite_limite f x x0 x1 p p0). -Qed. - - -(************************************************************) -(** Local extremum's condition *) -(************************************************************) - -Theorem deriv_maximum : (f:R->R;a,b,c:R;pr:(derivable_pt f c)) ``a<c``->``c<b``->((x:R) ``a<x``->``x<b``->``(f x)<=(f c)``)->``(derive_pt f c pr)==0``. -Intros; Case (total_order R0 (derive_pt f c pr)); Intro. -Assert H3 := (derivable_derive f c pr). -Elim H3; Intros l H4; Rewrite H4 in H2. -Assert H5 := (derive_pt_eq_1 f c l pr H4). -Cut ``0<l/2``; [Intro | Unfold Rdiv; Apply Rmult_lt_pos; [Assumption | Apply Rlt_Rinv; Sup0]]. -Elim (H5 ``l/2`` H6); Intros delta H7. -Cut ``0<(b-c)/2``. -Intro; Cut ``(Rmin delta/2 ((b-c)/2))<>0``. -Intro; Cut ``(Rabsolu (Rmin delta/2 ((b-c)/2)))<delta``. -Intro. -Assert H11 := (H7 ``(Rmin delta/2 ((b-c)/2))`` H9 H10). -Cut ``0<(Rmin (delta/2) ((b-c)/2))``. -Intro; Cut ``a<c+(Rmin (delta/2) ((b-c)/2))``. -Intro; Cut ``c+(Rmin (delta/2) ((b-c)/2))<b``. -Intro; Assert H15 := (H1 ``c+(Rmin (delta/2) ((b-c)/2))`` H13 H14). -Cut ``((f (c+(Rmin (delta/2) ((b-c)/2))))-(f c))/(Rmin (delta/2) ((b-c)/2))<=0``. -Intro; Cut ``-l<0``. -Intro; Unfold Rminus in H11. -Cut ``((f (c+(Rmin (delta/2) ((b+ -c)/2))))+ -(f c))/(Rmin (delta/2) ((b+ -c)/2))+ -l<0``. -Intro; Cut ``(Rabsolu (((f (c+(Rmin (delta/2) ((b+ -c)/2))))+ -(f c))/(Rmin (delta/2) ((b+ -c)/2))+ -l)) < l/2``. -Unfold Rabsolu; Case (case_Rabsolu ``((f (c+(Rmin (delta/2) ((b+ -c)/2))))+ -(f c))/(Rmin (delta/2) ((b+ -c)/2))+ -l``); Intro. -Replace `` -(((f (c+(Rmin (delta/2) ((b+ -c)/2))))+ -(f c))/(Rmin (delta/2) ((b+ -c)/2))+ -l)`` with ``l+ -(((f (c+(Rmin (delta/2) ((b+ -c)/2))))+ -(f c))/(Rmin (delta/2) ((b+ -c)/2)))``. -Intro; Generalize (Rlt_compatibility ``-l`` ``l+ -(((f (c+(Rmin (delta/2) ((b+ -c)/2))))+ -(f c))/(Rmin (delta/2) ((b+ -c)/2)))`` ``l/2`` H19); Repeat Rewrite <- Rplus_assoc; Rewrite Rplus_Ropp_l; Rewrite Rplus_Ol; Replace ``-l+l/2`` with ``-(l/2)``. -Intro; Generalize (Rlt_Ropp ``-(((f (c+(Rmin (delta/2) ((b+ -c)/2))))+ -(f c))/(Rmin (delta/2) ((b+ -c)/2)))`` ``-(l/2)`` H20); Repeat Rewrite Ropp_Ropp; Intro; Generalize (Rlt_trans ``0`` ``l/2`` ``((f (c+(Rmin (delta/2) ((b+ -c)/2))))+ -(f c))/(Rmin (delta/2) ((b+ -c)/2))`` H6 H21); Intro; Elim (Rlt_antirefl ``0`` (Rlt_le_trans ``0`` ``((f (c+(Rmin (delta/2) ((b+ -c)/2))))+ -(f c))/(Rmin (delta/2) ((b+ -c)/2))`` ``0`` H22 H16)). -Pattern 2 l; Rewrite double_var. -Ring. -Ring. -Intro. -Assert H20 := (Rle_sym2 ``0`` ``((f (c+(Rmin (delta/2) ((b+ -c)/2))))+ -(f c))/(Rmin (delta/2) ((b+ -c)/2))+ -l`` r). -Elim (Rlt_antirefl ? (Rle_lt_trans ? ? ? H20 H18)). -Assumption. -Rewrite <- Ropp_O; Replace ``((f (c+(Rmin (delta/2) ((b+ -c)/2))))+ -(f c))/(Rmin (delta/2) ((b+ -c)/2))+ -l`` with ``-(l+ -(((f (c+(Rmin (delta/2) ((b+ -c)/2))))-(f c))/(Rmin (delta/2) ((b+ -c)/2))))``. -Apply Rgt_Ropp; Change ``0<l+ -(((f (c+(Rmin (delta/2) ((b+ -c)/2))))-(f c))/(Rmin (delta/2) ((b+ -c)/2)))``; Apply gt0_plus_ge0_is_gt0; [Assumption | Rewrite <- Ropp_O; Apply Rge_Ropp; Apply Rle_sym1; Assumption]. -Ring. -Rewrite <- Ropp_O; Apply Rlt_Ropp; Assumption. -Replace ``((f (c+(Rmin (delta/2) ((b-c)/2))))-(f c))/(Rmin (delta/2) ((b-c)/2))`` with ``- (((f c)-(f (c+(Rmin (delta/2) ((b-c)/2)))))/(Rmin (delta/2) ((b-c)/2)))``. -Rewrite <- Ropp_O; Apply Rge_Ropp; Apply Rle_sym1; Unfold Rdiv; Apply Rmult_le_pos; [Generalize (Rle_compatibility_r ``-(f (c+(Rmin (delta*/2) ((b-c)*/2))))`` ``(f (c+(Rmin (delta*/2) ((b-c)*/2))))`` (f c) H15); Rewrite Rplus_Ropp_r; Intro; Assumption | Left; Apply Rlt_Rinv; Assumption]. -Unfold Rdiv. -Rewrite <- Ropp_mul1. -Repeat Rewrite <- (Rmult_sym ``/(Rmin (delta*/2) ((b-c)*/2))``). -Apply r_Rmult_mult with ``(Rmin (delta*/2) ((b-c)*/2))``. -Repeat Rewrite <- Rmult_assoc. -Rewrite <- Rinv_r_sym. -Repeat Rewrite Rmult_1l. -Ring. -Red; Intro. -Unfold Rdiv in H12; Rewrite H16 in H12; Elim (Rlt_antirefl ``0`` H12). -Red; Intro. -Unfold Rdiv in H12; Rewrite H16 in H12; Elim (Rlt_antirefl ``0`` H12). -Assert H14 := (Rmin_r ``(delta/2)`` ``((b-c)/2)``). -Assert H15 := (Rle_compatibility ``c`` ``(Rmin (delta/2) ((b-c)/2))`` ``(b-c)/2`` H14). -Apply Rle_lt_trans with ``c+(b-c)/2``. -Assumption. -Apply Rlt_monotony_contra with ``2``. -Sup0. -Replace ``2*(c+(b-c)/2)`` with ``c+b``. -Replace ``2*b`` with ``b+b``. -Apply Rlt_compatibility_r; Assumption. -Ring. -Unfold Rdiv; Rewrite Rmult_Rplus_distr. -Repeat Rewrite (Rmult_sym ``2``). -Rewrite Rmult_assoc; Rewrite <- Rinv_l_sym. -Rewrite Rmult_1r. -Ring. -DiscrR. -Apply Rlt_trans with c. -Assumption. -Pattern 1 c; Rewrite <- (Rplus_Or c); Apply Rlt_compatibility; Assumption. -Cut ``0<delta/2``. -Intro; Apply (Rmin_stable_in_posreal (mkposreal ``delta/2`` H12) (mkposreal ``(b-c)/2`` H8)). -Unfold Rdiv; Apply Rmult_lt_pos; [Apply (cond_pos delta) | Apply Rlt_Rinv; Sup0]. -Unfold Rabsolu; Case (case_Rabsolu (Rmin ``delta/2`` ``(b-c)/2``)). -Intro. -Cut ``0<delta/2``. -Intro. -Generalize (Rmin_stable_in_posreal (mkposreal ``delta/2`` H10) (mkposreal ``(b-c)/2`` H8)); Simpl; Intro; Elim (Rlt_antirefl ``0`` (Rlt_trans ``0`` ``(Rmin (delta/2) ((b-c)/2))`` ``0`` H11 r)). -Unfold Rdiv; Apply Rmult_lt_pos; [Apply (cond_pos delta) | Apply Rlt_Rinv; Sup0]. -Intro; Apply Rle_lt_trans with ``delta/2``. -Apply Rmin_l. -Unfold Rdiv; Apply Rlt_monotony_contra with ``2``. -Sup0. -Rewrite <- (Rmult_sym ``/2``); Rewrite <- Rmult_assoc; Rewrite <- Rinv_r_sym. -Rewrite Rmult_1l. -Replace ``2*delta`` with ``delta+delta``. -Pattern 2 delta; Rewrite <- (Rplus_Or delta); Apply Rlt_compatibility. -Rewrite Rplus_Or; Apply (cond_pos delta). -Symmetry; Apply double. -DiscrR. -Cut ``0<delta/2``. -Intro; Generalize (Rmin_stable_in_posreal (mkposreal ``delta/2`` H9) (mkposreal ``(b-c)/2`` H8)); Simpl; Intro; Red; Intro; Rewrite H11 in H10; Elim (Rlt_antirefl ``0`` H10). -Unfold Rdiv; Apply Rmult_lt_pos; [Apply (cond_pos delta) | Apply Rlt_Rinv; Sup0]. -Unfold Rdiv; Apply Rmult_lt_pos. -Generalize (Rlt_compatibility_r ``-c`` c b H0); Rewrite Rplus_Ropp_r; Intro; Assumption. -Apply Rlt_Rinv; Sup0. -Elim H2; Intro. -Symmetry; Assumption. -Generalize (derivable_derive f c pr); Intro; Elim H4; Intros l H5. -Rewrite H5 in H3; Generalize (derive_pt_eq_1 f c l pr H5); Intro; Cut ``0< -(l/2)``. -Intro; Elim (H6 ``-(l/2)`` H7); Intros delta H9. -Cut ``0<(c-a)/2``. -Intro; Cut ``(Rmax (-(delta/2)) ((a-c)/2))<0``. -Intro; Cut ``(Rmax (-(delta/2)) ((a-c)/2))<>0``. -Intro; Cut ``(Rabsolu (Rmax (-(delta/2)) ((a-c)/2)))<delta``. -Intro; Generalize (H9 ``(Rmax (-(delta/2)) ((a-c)/2))`` H11 H12); Intro; Cut ``a<c+(Rmax (-(delta/2)) ((a-c)/2))``. -Cut ``c+(Rmax (-(delta/2)) ((a-c)/2))<b``. -Intros; Generalize (H1 ``c+(Rmax (-(delta/2)) ((a-c)/2))`` H15 H14); Intro; Cut ``0<=((f (c+(Rmax (-(delta/2)) ((a-c)/2))))-(f c))/(Rmax (-(delta/2)) ((a-c)/2))``. -Intro; Cut ``0< -l``. -Intro; Unfold Rminus in H13; Cut ``0<((f (c+(Rmax (-(delta/2)) ((a+ -c)/2))))+ -(f c))/(Rmax (-(delta/2)) ((a+ -c)/2))+ -l``. -Intro; Cut ``(Rabsolu (((f (c+(Rmax (-(delta/2)) ((a+ -c)/2))))+ -(f c))/(Rmax (-(delta/2)) ((a+ -c)/2))+ -l)) < -(l/2)``. -Unfold Rabsolu; Case (case_Rabsolu ``((f (c+(Rmax (-(delta/2)) ((a+ -c)/2))))+ -(f c))/(Rmax (-(delta/2)) ((a+ -c)/2))+ -l``). -Intro; Elim (Rlt_antirefl ``0`` (Rlt_trans ``0`` ``((f (c+(Rmax ( -(delta/2)) ((a+ -c)/2))))+ -(f c))/(Rmax ( -(delta/2)) ((a+ -c)/2))+ -l`` ``0`` H19 r)). -Intros; Generalize (Rlt_compatibility_r ``l`` ``(((f (c+(Rmax (-(delta/2)) ((a+ -c)/2))))+ -(f c))/(Rmax (-(delta/2)) ((a+ -c)/2)))+ -l`` ``-(l/2)`` H20); Repeat Rewrite Rplus_assoc; Rewrite Rplus_Ropp_l; Rewrite Rplus_Or; Replace ``-(l/2)+l`` with ``l/2``. -Cut ``l/2<0``. -Intros; Generalize (Rlt_trans ``((f (c+(Rmax ( -(delta/2)) ((a+ -c)/2))))+ -(f c))/(Rmax ( -(delta/2)) ((a+ -c)/2))`` ``l/2`` ``0`` H22 H21); Intro; Elim (Rlt_antirefl ``0`` (Rle_lt_trans ``0`` ``((f (c+(Rmax ( -(delta/2)) ((a-c)/2))))-(f c))/(Rmax ( -(delta/2)) ((a-c)/2))`` ``0`` H17 H23)). -Rewrite <- (Ropp_Ropp ``l/2``); Rewrite <- Ropp_O; Apply Rlt_Ropp; Assumption. -Pattern 3 l; Rewrite double_var. -Ring. -Assumption. -Apply ge0_plus_gt0_is_gt0; Assumption. -Rewrite <- Ropp_O; Apply Rlt_Ropp; Assumption. -Unfold Rdiv; Replace ``((f (c+(Rmax ( -(delta*/2)) ((a-c)*/2))))-(f c))*/(Rmax ( -(delta*/2)) ((a-c)*/2))`` with ``(-((f (c+(Rmax ( -(delta*/2)) ((a-c)*/2))))-(f c)))*/(-(Rmax ( -(delta*/2)) ((a-c)*/2)))``. -Apply Rmult_le_pos. -Generalize (Rle_compatibility ``-(f (c+(Rmax (-(delta*/2)) ((a-c)*/2))))`` ``(f (c+(Rmax (-(delta*/2)) ((a-c)*/2))))`` (f c) H16); Rewrite Rplus_Ropp_l; Replace ``-((f (c+(Rmax ( -(delta*/2)) ((a-c)*/2))))-(f c))`` with ``-((f (c+(Rmax ( -(delta*/2)) ((a-c)*/2)))))+(f c)``. -Intro; Assumption. -Ring. -Left; Apply Rlt_Rinv; Rewrite <- Ropp_O; Apply Rlt_Ropp; Assumption. -Unfold Rdiv. -Rewrite <- Ropp_Rinv. -Rewrite Ropp_mul2. -Reflexivity. -Unfold Rdiv in H11; Assumption. -Generalize (Rlt_compatibility c ``(Rmax ( -(delta/2)) ((a-c)/2))`` ``0`` H10); Rewrite Rplus_Or; Intro; Apply Rlt_trans with ``c``; Assumption. -Generalize (RmaxLess2 ``(-(delta/2))`` ``((a-c)/2)``); Intro; Generalize (Rle_compatibility c ``(a-c)/2`` ``(Rmax ( -(delta/2)) ((a-c)/2))`` H14); Intro; Apply Rlt_le_trans with ``c+(a-c)/2``. -Apply Rlt_monotony_contra with ``2``. -Sup0. -Replace ``2*(c+(a-c)/2)`` with ``a+c``. -Rewrite double. -Apply Rlt_compatibility; Assumption. -Ring. -Rewrite <- Rplus_assoc. -Rewrite <- double_var. -Ring. -Assumption. -Unfold Rabsolu; Case (case_Rabsolu (Rmax ``-(delta/2)`` ``(a-c)/2``)). -Intro; Generalize (RmaxLess1 ``-(delta/2)`` ``(a-c)/2``); Intro; Generalize (Rle_Ropp ``-(delta/2)`` ``(Rmax ( -(delta/2)) ((a-c)/2))`` H12); Rewrite Ropp_Ropp; Intro; Generalize (Rle_sym2 ``-(Rmax ( -(delta/2)) ((a-c)/2))`` ``delta/2`` H13); Intro; Apply Rle_lt_trans with ``delta/2``. -Assumption. -Apply Rlt_monotony_contra with ``2``. -Sup0. -Unfold Rdiv; Rewrite <- (Rmult_sym ``/2``); Rewrite <- Rmult_assoc; Rewrite <- Rinv_r_sym. -Rewrite Rmult_1l; Rewrite double. -Pattern 2 delta; Rewrite <- (Rplus_Or delta); Apply Rlt_compatibility; Rewrite Rplus_Or; Apply (cond_pos delta). -DiscrR. -Cut ``-(delta/2) < 0``. -Cut ``(a-c)/2<0``. -Intros; Generalize (Rmax_stable_in_negreal (mknegreal ``-(delta/2)`` H13) (mknegreal ``(a-c)/2`` H12)); Simpl; Intro; Generalize (Rle_sym2 ``0`` ``(Rmax ( -(delta/2)) ((a-c)/2))`` r); Intro; Elim (Rlt_antirefl ``0`` (Rle_lt_trans ``0`` ``(Rmax ( -(delta/2)) ((a-c)/2))`` ``0`` H15 H14)). -Rewrite <- Ropp_O; Rewrite <- (Ropp_Ropp ``(a-c)/2``); Apply Rlt_Ropp; Replace ``-((a-c)/2)`` with ``(c-a)/2``. -Assumption. -Unfold Rdiv. -Rewrite <- Ropp_mul1. -Rewrite (Ropp_distr2 a c). -Reflexivity. -Rewrite <- Ropp_O; Apply Rlt_Ropp; Unfold Rdiv; Apply Rmult_lt_pos; [Apply (cond_pos delta) | Assert Hyp : ``0<2``; [Sup0 | Apply (Rlt_Rinv ``2`` Hyp)]]. -Red; Intro; Rewrite H11 in H10; Elim (Rlt_antirefl ``0`` H10). -Cut ``(a-c)/2<0``. -Intro; Cut ``-(delta/2)<0``. -Intro; Apply (Rmax_stable_in_negreal (mknegreal ``-(delta/2)`` H11) (mknegreal ``(a-c)/2`` H10)). -Rewrite <- Ropp_O; Apply Rlt_Ropp; Unfold Rdiv; Apply Rmult_lt_pos; [Apply (cond_pos delta) | Assert Hyp : ``0<2``; [Sup0 | Apply (Rlt_Rinv ``2`` Hyp)]]. -Rewrite <- Ropp_O; Rewrite <- (Ropp_Ropp ``(a-c)/2``); Apply Rlt_Ropp; Replace ``-((a-c)/2)`` with ``(c-a)/2``. -Assumption. -Unfold Rdiv. -Rewrite <- Ropp_mul1. -Rewrite (Ropp_distr2 a c). -Reflexivity. -Unfold Rdiv; Apply Rmult_lt_pos; [Generalize (Rlt_compatibility_r ``-a`` a c H); Rewrite Rplus_Ropp_r; Intro; Assumption | Assert Hyp : ``0<2``; [Sup0 | Apply (Rlt_Rinv ``2`` Hyp)]]. -Replace ``-(l/2)`` with ``(-l)/2``. -Unfold Rdiv; Apply Rmult_lt_pos. -Rewrite <- Ropp_O; Apply Rlt_Ropp; Assumption. -Assert Hyp : ``0<2``; [Sup0 | Apply (Rlt_Rinv ``2`` Hyp)]. -Unfold Rdiv; Apply Ropp_mul1. -Qed. - -Theorem deriv_minimum : (f:R->R;a,b,c:R;pr:(derivable_pt f c)) ``a<c``->``c<b``->((x:R) ``a<x``->``x<b``->``(f c)<=(f x)``)->``(derive_pt f c pr)==0``. -Intros. -Rewrite <- (Ropp_Ropp (derive_pt f c pr)). -Apply eq_RoppO. -Rewrite <- (derive_pt_opp f c pr). -Cut (x:R)(``a<x``->``x<b``->``((opp_fct f) x)<=((opp_fct f) c)``). -Intro. -Apply (deriv_maximum (opp_fct f) a b c (derivable_pt_opp ? ? pr) H H0 H2). -Intros; Unfold opp_fct; Apply Rge_Ropp; Apply Rle_sym1. -Apply (H1 x H2 H3). -Qed. - -Theorem deriv_constant2 : (f:R->R;a,b,c:R;pr:(derivable_pt f c)) ``a<c``->``c<b``->((x:R) ``a<x``->``x<b``->``(f x)==(f c)``)->``(derive_pt f c pr)==0``. -Intros. -EApply deriv_maximum with a b; Try Assumption. -Intros; Right; Apply (H1 x H2 H3). -Qed. - -(**********) -Lemma nonneg_derivative_0 : (f:R->R;pr:(derivable f)) (increasing f) -> ((x:R) ``0<=(derive_pt f x (pr x))``). -Intros; Unfold increasing in H. -Assert H0 := (derivable_derive f x (pr x)). -Elim H0; Intros l H1. -Rewrite H1; Case (total_order R0 l); Intro. -Left; Assumption. -Elim H2; Intro. -Right; Assumption. -Assert H4 := (derive_pt_eq_1 f x l (pr x) H1). -Cut ``0< -(l/2)``. -Intro; Elim (H4 ``-(l/2)`` H5); Intros delta H6. -Cut ``delta/2<>0``/\``0<delta/2``/\``(Rabsolu delta/2)<delta``. -Intro; Decompose [and] H7; Intros; Generalize (H6 ``delta/2`` H8 H11); Cut ``0<=((f (x+delta/2))-(f x))/(delta/2)``. -Intro; Cut ``0<=((f (x+delta/2))-(f x))/(delta/2)-l``. -Intro; Unfold Rabsolu; Case (case_Rabsolu ``((f (x+delta/2))-(f x))/(delta/2)-l``). -Intro; Elim (Rlt_antirefl ``0`` (Rle_lt_trans ``0`` ``((f (x+delta/2))-(f x))/(delta/2)-l`` ``0`` H12 r)). -Intros; Generalize (Rlt_compatibility_r l ``((f (x+delta/2))-(f x))/(delta/2)-l`` ``-(l/2)`` H13); Unfold Rminus; Replace ``-(l/2)+l`` with ``l/2``. -Rewrite Rplus_assoc; Rewrite Rplus_Ropp_l; Rewrite Rplus_Or; Intro; Generalize (Rle_lt_trans ``0`` ``((f (x+delta/2))-(f x))/(delta/2)`` ``l/2`` H9 H14); Intro; Cut ``l/2<0``. -Intro; Elim (Rlt_antirefl ``0`` (Rlt_trans ``0`` ``l/2`` ``0`` H15 H16)). -Rewrite <- Ropp_O in H5; Generalize (Rlt_Ropp ``-0`` ``-(l/2)`` H5); Repeat Rewrite Ropp_Ropp; Intro; Assumption. -Pattern 3 l ; Rewrite double_var. -Ring. -Unfold Rminus; Apply ge0_plus_ge0_is_ge0. -Unfold Rdiv; Apply Rmult_le_pos. -Cut ``x<=(x+(delta*/2))``. -Intro; Generalize (H x ``x+(delta*/2)`` H12); Intro; Generalize (Rle_compatibility ``-(f x)`` ``(f x)`` ``(f (x+delta*/2))`` H13); Rewrite Rplus_Ropp_l; Rewrite Rplus_sym; Intro; Assumption. -Pattern 1 x; Rewrite <- (Rplus_Or x); Apply Rle_compatibility; Left; Assumption. -Left; Apply Rlt_Rinv; Assumption. -Left; Rewrite <- Ropp_O; Apply Rlt_Ropp; Assumption. -Unfold Rdiv; Apply Rmult_le_pos. -Cut ``x<=(x+(delta*/2))``. -Intro; Generalize (H x ``x+(delta*/2)`` H9); Intro; Generalize (Rle_compatibility ``-(f x)`` ``(f x)`` ``(f (x+delta*/2))`` H12); Rewrite Rplus_Ropp_l; Rewrite Rplus_sym; Intro; Assumption. -Pattern 1 x; Rewrite <- (Rplus_Or x); Apply Rle_compatibility; Left; Assumption. -Left; Apply Rlt_Rinv; Assumption. -Split. -Unfold Rdiv; Apply prod_neq_R0. -Generalize (cond_pos delta); Intro; Red; Intro H9; Rewrite H9 in H7; Elim (Rlt_antirefl ``0`` H7). -Apply Rinv_neq_R0; DiscrR. -Split. -Unfold Rdiv; Apply Rmult_lt_pos; [Apply (cond_pos delta) | Apply Rlt_Rinv; Sup0]. -Replace ``(Rabsolu delta/2)`` with ``delta/2``. -Unfold Rdiv; Apply Rlt_monotony_contra with ``2``. -Sup0. -Rewrite (Rmult_sym ``2``). -Rewrite Rmult_assoc; Rewrite <- Rinv_l_sym; [Idtac | DiscrR]. -Rewrite Rmult_1r. -Rewrite double. -Pattern 1 (pos delta); Rewrite <- Rplus_Or. -Apply Rlt_compatibility; Apply (cond_pos delta). -Symmetry; Apply Rabsolu_right. -Left; Change ``0<delta/2``; Unfold Rdiv; Apply Rmult_lt_pos; [Apply (cond_pos delta) | Apply Rlt_Rinv; Sup0]. -Unfold Rdiv; Rewrite <- Ropp_mul1; Apply Rmult_lt_pos. -Apply Rlt_anti_compatibility with l. -Unfold Rminus; Rewrite Rplus_Ropp_r; Rewrite Rplus_Or; Assumption. -Apply Rlt_Rinv; Sup0. -Qed. |