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4 (* ||A|| A project by Andrea Asperti *)
6 (* ||I|| Developers: *)
7 (* ||T|| The HELM team. *)
8 (* ||A|| http://helm.cs.unibo.it *)
10 (* \ / This file is distributed under the terms of the *)
11 (* v GNU General Public License Version 2 *)
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15 (* manca un pezzo del pullback, se inverto poi non tipa *)
16 include "sandwich.ma".
17 include "property_exhaustivity.ma".
20 alias symbol "low" = "lower".
21 alias id "le" = "cic:/matita/dama/ordered_set/le.con".
22 lemma order_converges_bigger_lowsegment:
24 ∀a:sequence (os_l C).∀s:segment C.∀H:∀i:nat.a i ∈ s.
25 ∀x:C.∀p:order_converge C a x.
26 ∀j. seg_l (os_l C) s (λl.le (os_l C) l (pi1exT23 ???? p j)).
27 intros; cases p (xi yi Ux Dy Hxy); clear p; simplify;
28 cases Ux (Ixi Sxi); clear Ux; cases Dy (Dyi Iyi); clear Dy;
29 cases (Hxy j) (Ia Sa); clear Hxy; cases Ia (Da SSa); cases Sa (Inca SIa); clear Ia Sa;
30 cases (wloss_prop (os_l C))(W W);rewrite <W;
31 [ intro H2; cases (SSa (seg_l_ C s) H2) (w Hw); simplify in Hw;
32 lapply (H (w+j)) as K; unfold in K;
33 whd in K:(? % ? ? ? ?); simplify in K:(%); rewrite <W in K; cases K;
34 whd in H1:(? % ? ? ? ?); simplify in H1:(%); rewrite <W in H1;
35 simplify in H1; apply (H1 Hw);
36 | intro H2; cases (SSa (seg_u_ C s) H2) (w Hw); simplify in Hw;
37 lapply (H (w+j)) as K; unfold in K;
38 whd in K:(? % ? ? ? ?);simplify in K:(%); rewrite <W in K; cases K;
39 whd in H3:(? % ? ? ? ?);simplify in H3:(%); rewrite <W in H3;
40 simplify in H3; apply (H3 Hw);]
43 lemma order_converges_smaller_upsegment:
45 ∀a:sequence (os_l C).∀s:segment C.∀H:∀i:nat.a i ∈ s.
46 ∀x:C.∀p:order_converge C a x.
47 ∀j. seg_u (os_l C) s (λu.le (os_l C) (pi2exT23 ???? p j) u).
48 intros; cases p (xi yi Ux Dy Hxy); clear p; simplify;
49 cases Ux (Ixi Sxi); clear Ux; cases Dy (Dyi Iyi); clear Dy;
50 cases (Hxy j) (Ia Sa); clear Hxy; cases Ia (Da SSa); cases Sa (Inca SIa); clear Ia Sa;
51 cases (wloss_prop (os_l C))(W W); unfold os_r; unfold dual_hos; simplify;rewrite <W;
52 [ intro H2; cases (SIa (seg_u_ (os_l C) s) H2) (w Hw); simplify in Hw;
53 lapply (H (w+j)) as K; unfold in K; whd in K:(? % ? ? ? ?); simplify in K:(%);
54 rewrite <W in K; cases K; whd in H3:(? % ? ? ? ?); simplify in H3:(%); rewrite <W in H3;
55 simplify in H3; apply (H3 Hw);
56 | intro H2; cases (SIa (seg_l_ C s) H2) (w Hw); simplify in Hw;
57 lapply (H (w+j)) as K; unfold in K; whd in K:(? % ? ? ? ?); simplify in K:(%);
58 rewrite <W in K; cases K; whd in H1:(? % ? ? ? ?); simplify in H1:(%);
59 rewrite <W in H1; simplify in H1; apply (H1 Hw);]
62 alias symbol "upp" = "uppper".
63 alias symbol "leq" = "Ordered set less or equal than".
64 lemma cases_in_segment:
65 ∀C:half_ordered_set.∀s:segment C.∀x. x ∈ s → seg_l C s (λl.l ≤≤ x) ∧ seg_u C s (λu.x ≤≤ u).
66 intros; unfold in H; cases (wloss_prop C) (W W); rewrite<W in H; [cases H; split;assumption]
67 cases H; split; assumption;
70 lemma trans_under_upp:
71 ∀O:ordered_set.∀s:‡O.∀x,y:O.
72 x ≤ y → 𝕦_s (λu.y ≤ u) → 𝕦_s (λu.x ≤ u).
73 intros; cases (wloss_prop (os_l O)) (W W); unfold; unfold in H1; rewrite<W in H1 ⊢ %;
74 apply (le_transitive ??? H H1);
77 lemma trans_under_low:
78 ∀O:ordered_set.∀s:‡O.∀x,y:O.
79 y ≤ x → 𝕝_s (λl.l ≤ y) → 𝕝_s (λl.l ≤ x).
80 intros; cases (wloss_prop (os_l O)) (W W); unfold; unfold in H1; rewrite<W in H1 ⊢ %;
81 apply (le_transitive ??? H1 H);
85 ∀C,s.∀x,y:half_segment_ordered_set C s. \fst x ≤≤ \fst y → x ≤≤ y.
86 intros; unfold in H ⊢ %; intro; apply H; clear H; unfold in H1 ⊢ %;
87 cases (wloss_prop C) (W W); whd in H1:(? (% ? ?) ? ? ? ?); simplify in H1:(%);
88 rewrite < W in H1 ⊢ %; apply H1;
93 ∀C:ordered_uniform_space.
94 (∀s:‡C.order_continuity {[s]}) →
95 ∀a:sequence C.∀s:‡C.∀H:∀i:nat.a i ∈ s.
96 ∀x:C.a order_converges x →
99 uniform_converge {[s]} (⌊n,≪a n,H n≫⌋) ≪x,h≫.
101 generalize in match (order_converges_bigger_lowsegment ? a s H1 ? H2);
102 generalize in match (order_converges_smaller_upsegment ? a s H1 ? H2);
103 cases H2 (xi yi Hx Hy Hxy); clear H2; simplify in ⊢ ((?→???%) → (?→???%) → ?); intros;
104 cut (∀i.xi i ∈ s) as Hxi; [2:
105 intros; apply (prove_in_segment (os_l C)); [apply (H3 i)] cases (Hxy i) (H5 _); cases H5 (H7 _);
106 lapply (H7 0) as K; cases (cases_in_segment ? s ? (H1 i)) (Pl Pu); simplify in K;
107 apply (trans_under_upp ?? (xi i) (a i) K Pu);] clear H3;
108 cut (∀i.yi i ∈ s) as Hyi; [2:
109 intros; apply (prove_in_segment (os_l C)); [2:apply (H2 i)] cases (Hxy i) (_ H5); cases H5 (H7 _);
110 lapply (H7 0) as K; cases (cases_in_segment ? s ? (H1 i)) (Pl Pu); simplify in K;
111 apply (trans_under_low ?? (yi i) (a i) K Pl);] clear H2;
113 [1: apply (uparrow_to_in_segment s ? Hxi ? Hx);
115 letin Xi ≝ (⌊n,≪xi n, Hxi n≫⌋);
116 letin Yi ≝ (⌊n,≪yi n, Hyi n≫⌋);
117 letin Ai ≝ (⌊n,≪a n, H1 n≫⌋);
118 apply (sandwich {[s]} ≪x, h≫ Xi Yi Ai); [4: assumption;]
119 [1: intro j; cases (Hxy j); cases H3; cases H4; split; clear H3 H4; simplify in H5 H7;
120 [apply (l2sl ? s (Xi j) (Ai j) (H5 0));|apply (l2sl ? s (Ai j) (Yi j) (H7 0))]
121 |2: cases (H s Xi ≪?,h≫) (Ux Uy); apply Ux; cases Hx; split; [intro i; apply (l2sl ? s (Xi i) (Xi (S i)) (H3 i));]
122 cases H4; split; [intro i; apply (l2sl ? s (Xi i) ≪x,h≫ (H5 i))]
123 intros (y Hy);cases (H6 (\fst y));[2:apply (sx2x ? s ? y Hy)]
124 exists [apply w] apply (x2sx ? s (Xi w) y H7);
125 |3: cases (H s Yi ≪?,h≫) (Ux Uy); apply Uy; cases Hy; split; [intro i; apply (l2sl ? s (Yi (S i)) (Yi i) (H3 i));]
126 cases H4; split; [intro i; apply (l2sl ? s ≪x,h≫ (Yi i) (H5 i))]
127 intros (y Hy);cases (H6 (\fst y));[2:apply (sx2x ? s y ≪x,h≫ Hy)]
128 exists [apply w] apply (x2sx ? s y (Yi w) H7);]]
134 ∀C:ordered_uniform_space.property_sigma C →
135 (∀s:‡C.exhaustive {[s]}) →
136 ∀a:sequence C.∀s:‡C.∀H:∀i:nat.a i ∈ s.
137 ∀x:C.a order_converges x →
140 uniform_converge {[s]} (⌊n,≪a n,H n≫⌋) ≪x,h≫.
142 generalize in match (order_converges_bigger_lowsegment ? a s H1 ? H2);
143 generalize in match (order_converges_smaller_upsegment ? a s H1 ? H2);
144 cases H2 (xi yi Hx Hy Hxy); clear H2; simplify in ⊢ ((?→???%) → (?→???%) → ?); intros;
145 cut (∀i.xi i ∈ s) as Hxi; [2:
146 intros; apply (prove_in_segment (os_l C)); [apply (H3 i)] cases (Hxy i) (H5 _); cases H5 (H7 _);
147 lapply (H7 0) as K; cases (cases_in_segment ? s ? (H1 i)) (Pl Pu); simplify in K;
148 apply (trans_under_upp ?? (xi i) (a i) K Pu);] clear H3;
149 cut (∀i.yi i ∈ s) as Hyi; [2:
150 intros; apply (prove_in_segment (os_l C)); [2:apply (H2 i)] cases (Hxy i) (_ H5); cases H5 (H7 _);
151 lapply (H7 0) as K; cases (cases_in_segment ? s ? (H1 i)) (Pl Pu); simplify in K;
152 apply (trans_under_low ?? (yi i) (a i) K Pl);] clear H2;
153 letin Xi ≝ (⌊n,≪xi n, Hxi n≫⌋);
154 letin Yi ≝ (⌊n,≪yi n, Hyi n≫⌋);
155 cases (restrict_uniform_convergence_uparrow ? S ? (H s) Xi x Hx);
156 cases (restrict_uniform_convergence_downarrow ? S ? (H s) Yi x Hy);
157 split; [1: assumption]
159 lapply (uparrow_upperlocated xi x Hx)as Ux;
160 lapply (downarrow_lowerlocated yi x Hy)as Uy;
161 letin Ai ≝ (⌊n,≪a n, H1 n≫⌋);
162 apply (sandwich {[s]} ≪x, h≫ Xi Yi Ai); [4: assumption;|2:apply H3;|3:apply H5]
163 intro j; cases (Hxy j); cases H7; cases H8; split;
164 [apply (l2sl ? s (Xi j) (Ai j) (H9 0));|apply (l2sl ? s (Ai j) (Yi j) (H11 0))]