1 (**************************************************************************)
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 *)
13 (**************************************************************************)
15 include "o-algebra.ma".
16 include "o-saturations.ma".
18 record basic_topology: Type ≝
20 A: arrows1 SET (oa_P carrbt) (oa_P carrbt);
21 J: arrows1 SET (oa_P carrbt) (oa_P carrbt);
22 A_is_saturation: is_saturation ? A;
23 J_is_reduction: is_reduction ? J;
24 compatibility: ∀U,V. (A U >< J V) = (U >< J V)
27 record continuous_relation (S,T: basic_topology) : Type ≝
28 { cont_rel:> arrows1 ? S T;
29 (* reduces uses eq1, saturated uses eq!!! *)
30 reduced: ∀U. U = J ? U → cont_rel U = J ? (cont_rel U);
31 saturated: ∀U. U = A ? U → cont_rel⎻* U = A ? (cont_rel⎻* U)
34 definition continuous_relation_setoid: basic_topology → basic_topology → setoid1.
35 intros (S T); constructor 1;
36 [ apply (continuous_relation S T)
38 [ apply (λr,s:continuous_relation S T.∀b. eq1 (oa_P (carrbt S)) (A ? (r⎻ b)) (A ? (s⎻ b)));
39 | simplify; intros; apply refl1;
40 | simplify; intros; apply sym1; apply H
41 | simplify; intros; apply trans1; [2: apply H |3: apply H1; |1: skip]]]
44 definition cont_rel': ∀S,T: basic_topology. continuous_relation_setoid S T → arrows1 ? S T ≝ cont_rel.
48 definition cont_rel'':
50 continuous_relation_setoid S T → unary_morphism (oa_P (carrbt S)) (oa_P (carrbt T)).
51 intros; apply rule cont_rel; apply c;
56 theorem continuous_relation_eq':
57 ∀o1,o2.∀a,a': continuous_relation_setoid o1 o2.
58 a = a' → ∀X.a⎻* (A o1 X) = a'⎻* (A o1 X).
59 intros; apply oa_leq_antisym; intro; unfold minus_star_image; simplify; intros;
60 [ cut (ext ?? a a1 ⊆ A ? X); [2: intros 2; apply (H1 a2); cases f1; assumption;]
61 lapply (if ?? (A_is_saturation ???) Hcut); clear Hcut;
62 cut (A ? (ext ?? a' a1) ⊆ A ? X); [2: apply (. (H ?)‡#); assumption]
63 lapply (fi ?? (A_is_saturation ???) Hcut);
64 apply (Hletin1 x); change with (x ∈ ext ?? a' a1); split; simplify;
65 [ apply I | assumption ]
66 | cut (ext ?? a' a1 ⊆ A ? X); [2: intros 2; apply (H1 a2); cases f1; assumption;]
67 lapply (if ?? (A_is_saturation ???) Hcut); clear Hcut;
68 cut (A ? (ext ?? a a1) ⊆ A ? X); [2: apply (. (H ?)\sup -1‡#); assumption]
69 lapply (fi ?? (A_is_saturation ???) Hcut);
70 apply (Hletin1 x); change with (x ∈ ext ?? a a1); split; simplify;
71 [ apply I | assumption ]]
74 theorem continuous_relation_eq_inv':
75 ∀o1,o2.∀a,a': continuous_relation_setoid o1 o2.
76 (∀X.a⎻* (A o1 X) = a'⎻* (A o1 X)) → a=a'.
78 cut (∀a,a': continuous_relation_setoid o1 o2.
79 (∀X.a⎻* (A o1 X) = a'⎻* (A o1 X)) →
80 ∀V:(oa_P (carrbt o2)). A o1 (a'⎻ V) ≤ A o1 (a⎻ V));
81 [2: clear b H a' a; intros;
82 lapply depth=0 (λV.saturation_expansive ??? (extS ?? a V)); [2: apply A_is_saturation;|skip]
83 (* fundamental adjunction here! to be taken out *)
84 cut (∀V:Ω \sup o2.V ⊆ minus_star_image ?? a (A ? (extS ?? a V)));
85 [2: intro; intros 2; unfold minus_star_image; simplify; intros;
86 apply (Hletin V1 x); whd; split; [ exact I | exists; [apply a1] split; assumption]]
88 cut (∀V:Ω \sup o2.V ⊆ minus_star_image ?? a' (A ? (extS ?? a V)));
89 [2: intro; apply (. #‡(H ?)); apply Hcut] clear H Hcut;
90 (* second half of the fundamental adjunction here! to be taken out too *)
91 intro; lapply (Hcut1 (singleton ? V)); clear Hcut1;
92 unfold minus_star_image in Hletin; unfold singleton in Hletin; simplify in Hletin;
93 whd in Hletin; whd in Hletin:(?→?→%); simplify in Hletin;
94 apply (if ?? (A_is_saturation ???));
95 intros 2 (x H); lapply (Hletin V ? x ?);
96 [ apply refl | cases H; assumption; ]
97 change with (x ∈ A ? (ext ?? a V));
98 apply (. #‡(†(extS_singleton ????)));
100 split; apply Hcut; [2: assumption | intro; apply sym1; apply H]
103 definition continuous_relation_comp:
105 continuous_relation_setoid o1 o2 →
106 continuous_relation_setoid o2 o3 →
107 continuous_relation_setoid o1 o3.
108 intros (o1 o2 o3 r s); constructor 1;
112 change in match ((s ∘ r) U) with (s (r U));
113 (*BAD*) unfold FunClass_1_OF_carr1;
114 apply (.= ((reduced : ?)\sup -1));
115 [ (*BAD*) change with (eq1 ? (r U) (J ? (r U)));
116 (* BAD U *) apply (.= (reduced ??? U ?)); [ assumption | apply refl1 ]
120 change in match ((s ∘ r)⎻* U) with (s⎻* (r⎻* U));
121 apply (.= (saturated : ?)\sup -1);
122 [ apply (.= (saturated : ?)); [ assumption | apply refl ]
126 definition BTop: category1.
128 [ apply basic_topology
129 | apply continuous_relation_setoid
130 | intro; constructor 1;
134 | intros; constructor 1;
135 [ apply continuous_relation_comp;
136 | intros; simplify; intro x; simplify; (*
137 lapply depth=0 (continuous_relation_eq' ???? H) as H';
138 lapply depth=0 (continuous_relation_eq' ???? H1) as H1';
139 letin K ≝ (λX.H1' (minus_star_image ?? a (A ? X))); clearbody K;
141 minus_star_image o2 o3 b (A o2 (minus_star_image o1 o2 a (A o1 X)))
142 = minus_star_image o2 o3 b' (A o2 (minus_star_image o1 o2 a' (A o1 X))));
143 [2: intro; apply sym1; apply (.= #‡(†((H' ?)\sup -1))); apply sym1; apply (K X);]
146 minus_star_image o1 o3 (b ∘ a) (A o1 X) = minus_star_image o1 o3 (b'∘a') (A o1 X));
148 apply (.= (minus_star_image_comp ??????));
149 apply (.= #‡(saturated ?????));
150 [ apply ((saturation_idempotent ????) \sup -1); apply A_is_saturation ]
152 apply (.= (minus_star_image_comp ??????));
153 apply (.= #‡(saturated ?????));
154 [ apply ((saturation_idempotent ????) \sup -1); apply A_is_saturation ]
155 apply ((Hcut X) \sup -1)]
156 clear Hcut; generalize in match x; clear x;
157 apply (continuous_relation_eq_inv');
159 | intros; simplify; intro; do 2 (unfold continuous_relation_comp); simplify;
160 (*apply (.= †(ASSOC1‡#));
162 | intros; simplify; intro; unfold continuous_relation_comp; simplify;
163 (*apply (.= †((id_neutral_right1 ????)‡#));
165 | intros; simplify; intro; simplify;
166 apply (.= †((id_neutral_left1 ????)‡#));
172 (* this proof is more logic-oriented than set/lattice oriented *)
173 theorem continuous_relation_eqS:
174 ∀o1,o2:basic_topology.∀a,a': continuous_relation_setoid o1 o2.
175 a = a' → ∀X. A ? (extS ?? a X) = A ? (extS ?? a' X).
177 cut (∀a: arrows1 ? o1 ?.∀x. x ∈ extS ?? a X → ∃y:o2.y ∈ X ∧ x ∈ ext ?? a y);
178 [2: intros; cases f; clear f; cases H1; exists [apply w] cases x1; split;
179 try assumption; split; assumption]
180 cut (∀a,a':continuous_relation_setoid o1 o2.eq1 ? a a' → ∀x. x ∈ extS ?? a X → ∃y:o2. y ∈ X ∧ x ∈ A ? (ext ?? a' y));
181 [2: intros; cases (Hcut ?? f); exists; [apply w] cases x1; split; try assumption;
183 apply (saturation_expansive ?? (A_is_saturation o1) (ext ?? a1 w) x);
184 assumption;] clear Hcut;
185 split; apply (if ?? (A_is_saturation ???)); intros 2;
186 [lapply (Hcut1 a a' H a1 f) | lapply (Hcut1 a' a (H \sup -1) a1 f)]
187 cases Hletin; clear Hletin; cases x; clear x;
188 cut (∀a: arrows1 ? o1 ?. ext ?? a w ⊆ extS ?? a X);
189 [2,4: intros 3; cases f3; clear f3; simplify in f5; split; try assumption;
190 exists [1,3: apply w] split; assumption;]
191 cut (∀a. A ? (ext o1 o2 a w) ⊆ A ? (extS o1 o2 a X));
192 [2,4: intros; apply saturation_monotone; try (apply A_is_saturation); apply Hcut;]
193 apply Hcut2; assumption.