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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 include "datatypes/subsets.ma".
16 include "logic/cprop_connectives.ma".
17 include "formal_topology/categories.ma".
19 record basic_pair: Type ≝
24 rel: binary_relation ?? concr form
27 notation "x ⊩ y" with precedence 45 for @{'Vdash2 $x $y}.
28 notation "⊩" with precedence 60 for @{'Vdash}.
30 interpretation "basic pair relation" 'Vdash2 x y = (rel _ x y).
31 interpretation "basic pair relation (non applied)" 'Vdash = (rel _).
33 alias symbol "eq" = "equal relation".
34 alias symbol "compose" = "binary relation composition".
35 record relation_pair (BP1,BP2: basic_pair): Type ≝
36 { concr_rel: binary_relation ?? (concr BP1) (concr BP2);
37 form_rel: binary_relation ?? (form BP1) (form BP2);
38 commute: concr_rel ∘ ⊩ = ⊩ ∘ form_rel
41 notation "hvbox (r \sub \c)" with precedence 90 for @{'concr_rel $r}.
42 notation "hvbox (r \sub \f)" with precedence 90 for @{'form_rel $r}.
44 interpretation "concrete relation" 'concr_rel r = (concr_rel __ r).
45 interpretation "formal relation" 'form_rel r = (form_rel __ r).
48 definition relation_pair_equality:
49 ∀o1,o2. equivalence_relation (relation_pair o1 o2).
52 [ apply (λr,r'. r \sub\c ∘ ⊩ = r' \sub\c ∘ ⊩);
55 apply refl_equal_relations;
58 apply sym_equal_relations;
62 apply (trans_equal_relations ??????? H);
67 definition relation_pair_setoid: basic_pair → basic_pair → setoid.
70 [ apply (relation_pair b b1)
71 | apply relation_pair_equality
76 λo1,o2.λr,r':relation_pair o1 o2.⊩ ∘ r \sub\f = ⊩ ∘ r' \sub\f.
78 alias symbol "eq" = "setoid eq".
79 lemma eq_to_eq': ∀o1,o2.∀r,r': relation_pair_setoid o1 o2. r=r' → eq' ?? r r'.
80 intros 7 (o1 o2 r r' H c1 f2);
82 [ lapply (fi ?? (commute ?? r c1 f2) H1) as H2;
83 lapply (if ?? (H c1 f2) H2) as H3;
84 apply (if ?? (commute ?? r' c1 f2) H3);
85 | lapply (fi ?? (commute ?? r' c1 f2) H1) as H2;
86 lapply (fi ?? (H c1 f2) H2) as H3;
87 apply (if ?? (commute ?? r c1 f2) H3);
92 definition id: ∀o:basic_pair. relation_pair o o.
102 cases H1; clear H H1;
105 [ rewrite > H2; assumption
109 [2: rewrite < H3; assumption
113 definition relation_pair_composition:
114 ∀o1,o2,o3. binary_morphism (relation_pair_setoid o1 o2) (relation_pair_setoid o2 o3) (relation_pair_setoid o1 o3).
119 [ apply (r \sub\c ∘ r1 \sub\c)
120 | apply (r \sub\f ∘ r1 \sub\f)
121 | lapply (commute ?? r) as H;
122 lapply (commute ?? r1) as H1;
123 apply (equal_morphism ???? (r\sub\c ∘ (r1\sub\c ∘ ⊩)) ? ((⊩ ∘ r\sub\f) ∘ r1\sub\f));
124 [1,2: apply associative_composition]
125 apply (equal_morphism ???? (r\sub\c ∘ (⊩ ∘ r1\sub\f)) ? ((r\sub\c ∘ ⊩) ∘ r1\sub\f));
126 [1,2: apply composition_morphism; first [assumption | apply refl_equal_relations]
127 | apply sym_equal_relations;
128 apply associative_composition
131 alias symbol "eq" = "equal relation".
132 change with (a\sub\c ∘ b\sub\c ∘ ⊩ = a'\sub\c ∘ b'\sub\c ∘ ⊩);
133 apply (equal_morphism ???? (a\sub\c ∘ (b\sub\c ∘ ⊩)) ? (a'\sub\c ∘ (b'\sub\c ∘ ⊩)));
134 [ apply associative_composition
135 | apply sym_equal_relations; apply associative_composition]
136 apply (equal_morphism ???? (a\sub\c ∘ (b'\sub\c ∘ ⊩)) ? (a' \sub \c∘(b' \sub \c∘⊩)));
137 [2: apply refl_equal_relations;
138 |1: apply composition_morphism;
139 [ apply refl_equal_relations
141 apply (equal_morphism ???? (a\sub\c ∘ (⊩ ∘ b'\sub\f)) ? (a'\sub\c ∘ (⊩ ∘ b'\sub\f)));
142 [1,2: apply composition_morphism;
143 [1,3: apply refl_equal_relations
144 | apply (commute ?? b');
145 | apply sym_equal_relations; apply (commute ?? b');]]
146 apply (equal_morphism ???? ((a\sub\c ∘ ⊩) ∘ b'\sub\f) ? ((a'\sub\c ∘ ⊩) ∘ b'\sub\f));
147 [2: apply associative_composition
148 |1: apply sym_equal_relations; apply associative_composition]
149 apply composition_morphism;
151 | apply refl_equal_relations]]
154 definition BP: category.
157 | apply relation_pair_setoid
159 | apply relation_pair_composition
161 change with (a12\sub\c ∘ a23\sub\c ∘ a34\sub\c ∘ ⊩ =
162 (a12\sub\c ∘ (a23\sub\c ∘ a34\sub\c) ∘ ⊩));
163 apply composition_morphism;
164 [2: apply refl_equal_relations]
165 apply associative_composition
167 change with ((id o1)\sub\c ∘ a\sub\c ∘ ⊩ = a\sub\c ∘ ⊩);
168 apply composition_morphism;
169 [2: apply refl_equal_relations]
170 intros 2; unfold id; simplify;
172 [ cases H; cases H1; rewrite > H2; assumption
173 | exists; [assumption] split; [reflexivity| assumption]]
175 change with (a\sub\c ∘ (id o2)\sub\c ∘ ⊩ = a\sub\c ∘ ⊩);
176 apply composition_morphism;
177 [2: apply refl_equal_relations]
178 intros 2; unfold id; simplify;
180 [ cases H; cases H1; rewrite < H3; assumption
181 | exists; [assumption] split; [assumption|reflexivity]]