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 (******************* SETS OVER TYPES *****************)
17 include "logic/connectives.ma".
19 nrecord powerclass (A: Type[0]) : Type[1] ≝ { mem: A → CProp[0] }.
21 interpretation "mem" 'mem a S = (mem ? S a).
22 interpretation "powerclass" 'powerset A = (powerclass A).
23 interpretation "subset construction" 'subset \eta.x = (mk_powerclass ? x).
25 ndefinition subseteq ≝ λA.λU,V.∀a:A. a ∈ U → a ∈ V.
26 interpretation "subseteq" 'subseteq U V = (subseteq ? U V).
28 ndefinition overlaps ≝ λA.λU,V.∃x:A.x ∈ U ∧ x ∈ V.
29 interpretation "overlaps" 'overlaps U V = (overlaps ? U V).
31 ndefinition intersect ≝ λA.λU,V:Ω^A.{ x | x ∈ U ∧ x ∈ V }.
32 interpretation "intersect" 'intersects U V = (intersect ? U V).
34 ndefinition union ≝ λA.λU,V:Ω^A.{ x | x ∈ U ∨ x ∈ V }.
35 interpretation "union" 'union U V = (union ? U V).
37 ndefinition big_union ≝ λA,B.λT:Ω^A.λf:A → Ω^B.{ x | ∃i. i ∈ T ∧ x ∈ f i }.
39 ndefinition big_intersection ≝ λA,B.λT:Ω^A.λf:A → Ω^B.{ x | ∀i. i ∈ T → x ∈ f i }.
41 ndefinition full_set: ∀A. Ω^A ≝ λA.{ x | True }.
42 ncoercion full_set : ∀A:Type[0]. Ω^A ≝ full_set on A: Type[0] to (Ω^?).
44 nlemma subseteq_refl: ∀A.∀S: Ω^A. S ⊆ S.
45 #A; #S; #x; #H; nassumption.
48 nlemma subseteq_trans: ∀A.∀S,T,U: Ω^A. S ⊆ T → T ⊆ U → S ⊆ U.
49 #A; #S; #T; #U; #H1; #H2; #x; #P; napply H2; napply H1; nassumption.
52 include "properties/relations1.ma".
54 ndefinition seteq: ∀A. equivalence_relation1 (Ω^A).
55 #A; napply mk_equivalence_relation1
56 [ napply (λS,S'. S ⊆ S' ∧ S' ⊆ S)
57 | #S; @; napply subseteq_refl
58 | #S; #S'; *; #H1; #H2; @; nassumption
59 | #S; #T; #U; *; #H1; #H2; *; #H3; #H4; @; napply subseteq_trans;
60 ##[##2,5: nassumption |##1,4: ##skip |##*: nassumption]##]
63 include "sets/setoids1.ma".
65 ndefinition powerclass_setoid: Type[0] → setoid1.
66 #A; @[ napply (Ω^A)| napply seteq ]
69 include "hints_declaration.ma".
71 alias symbol "hint_decl" = "hint_decl_Type2".
72 unification hint 0 ≔ A ⊢ carr1 (powerclass_setoid A) ≡ Ω^A.
74 (************ SETS OVER SETOIDS ********************)
76 include "logic/cprop.ma".
78 nrecord qpowerclass (A: setoid) : Type[1] ≝
79 { pc:> Ω^A; (* qui pc viene dichiarato con un target preciso...
80 forse lo si vorrebbe dichiarato con un target più lasco
81 ma la sintassi :> non lo supporta *)
82 mem_ok': ∀x,x':A. x=x' → (x ∈ pc) = (x' ∈ pc)
85 ndefinition Full_set: ∀A. qpowerclass A.
88 | #x; #x'; #H; napply refl1; ##]
91 ndefinition qseteq: ∀A. equivalence_relation1 (qpowerclass A).
93 [ napply (λS,S'. S = S')
94 | #S; napply (refl1 ? (seteq A))
95 | #S; #S'; napply (sym1 ? (seteq A))
96 | #S; #T; #U; napply (trans1 ? (seteq A))]
99 ndefinition qpowerclass_setoid: setoid → setoid1.
101 [ napply (qpowerclass A)
102 | napply (qseteq A) ]
105 unification hint 0 ≔ A ⊢
106 carr1 (qpowerclass_setoid A) ≡ qpowerclass A.
108 nlemma mem_ok: ∀A. binary_morphism1 (setoid1_of_setoid A) (qpowerclass_setoid A) CPROP.
110 [ napply (λx,S. x ∈ S)
111 | #a; #a'; #b; #b'; #Ha; *; #Hb1; #Hb2; napply mk_iff; #H;
112 ##[ napply Hb1; napply (. (mem_ok' …)); ##[##3: napply H| napply Ha^-1;##]
113 ##| napply Hb2; napply (. (mem_ok' …)); ##[##3: napply H| napply Ha;##]
119 A : setoid, x, S ⊢ (mem_ok A) x S ≡ mem A S x.
121 nlemma subseteq_ok: ∀A. binary_morphism1 (qpowerclass_setoid A) (qpowerclass_setoid A) CPROP.
123 [ napply (λS,S'. S ⊆ S')
124 | #a; #a'; #b; #b'; *; #Ha1; #Ha2; *; #Hb1; #Hb2; napply mk_iff; #H
125 [ napply (subseteq_trans … a)
126 [ nassumption | napply (subseteq_trans … b); nassumption ]
127 ##| napply (subseteq_trans … a')
128 [ nassumption | napply (subseteq_trans … b'); nassumption ] ##]
131 nlemma intersect_ok: ∀A. binary_morphism1 (qpowerclass_setoid A) (qpowerclass_setoid A) (qpowerclass_setoid A).
135 | #a; #a'; #Ha; nwhd in ⊢ (? ? ? % %); napply mk_iff; *; #H1; #H2; @
136 [##1,2: napply (. (mem_ok' …)^-1) [##3,6: nassumption |##2,5: nassumption |##*: ##skip]
137 ##|##3,4: napply (. (mem_ok' …)) [##1,3,4,6: nassumption |##*: ##skip]##]##]
138 ##| #a; #a'; #b; #b'; #Ha; #Hb; nwhd; @; #x; nwhd in ⊢ (% → %); #H
139 [ napply (. ((#‡Ha^-1)‡(#‡Hb^-1))); nassumption
140 | napply (. ((#‡Ha)‡(#‡Hb))); nassumption ]##]
143 (* unfold if intersect, exposing fun21 *)
144 alias symbol "hint_decl" = "hint_decl_Type1".
146 A : setoid, B,C : qpowerclass A ⊢
147 pc A (intersect_ok A B C) ≡ intersect ? (pc ? B) (pc ? C).
149 (* hints can pass under mem *) (* ??? XXX why is it needed? *)
150 unification hint 0 ≔ A,B,x ;
152 (*---------------------*) ⊢
153 mem A B x ≡ mem A C x.
155 nlemma test: ∀A:setoid. ∀U,V:qpowerclass A. ∀x,x':setoid1_of_setoid A. x=x' → x ∈ U ∩ V → x' ∈ U ∩ V.
156 #A; #U; #V; #x; #x'; #H; #p; napply (. (H^-1‡#)); nassumption.
159 ndefinition image: ∀A,B. (carr A → carr B) → Ω^A → Ω^B ≝
160 λA,B:setoid.λf:carr A → carr B.λSa:Ω^A.
161 {y | ∃x. x ∈ Sa ∧ eq_rel (carr B) (eq B) (f x) y}.
163 ndefinition counter_image: ∀A,B. (carr A → carr B) → Ω^B → Ω^A ≝
164 λA,B,f,Sb. {x | ∃y. y ∈ Sb ∧ f x = y}.
166 (******************* compatible equivalence relations **********************)
168 nrecord compatible_equivalence_relation (A: setoid) : Type[1] ≝
169 { rel:> equivalence_relation A;
170 compatibility: ∀x,x':A. x=x' → rel x x'
171 (* coercion qui non andava per via di un Failure invece di Uncertain
172 ritornato dall'unificazione per il problema:
173 ?[] A =?= ?[Γ]->?[Γ+1]
177 ndefinition quotient: ∀A. compatible_equivalence_relation A → setoid.
181 (******************* first omomorphism theorem for sets **********************)
183 ndefinition eqrel_of_morphism:
184 ∀A,B. unary_morphism A B → compatible_equivalence_relation A.
185 #A; #B; #f; napply mk_compatible_equivalence_relation
187 [ napply (λx,y. f x = f y)
188 | #x; napply refl | #x; #y; napply sym | #x; #y; #z; napply trans]
189 ##| #x; #x'; #H; nwhd; napply (.= (†H)); napply refl ]
192 ndefinition canonical_proj: ∀A,R. unary_morphism A (quotient A R).
194 [ napply (λx.x) | #a; #a'; #H; napply (compatibility … R … H) ]
197 ndefinition quotiented_mor:
198 ∀A,B.∀f:unary_morphism A B.
199 unary_morphism (quotient … (eqrel_of_morphism … f)) B.
201 [ napply f | #a; #a'; #H; nassumption]
204 nlemma first_omomorphism_theorem_functions1:
205 ∀A,B.∀f: unary_morphism A B.
206 ∀x. f x = quotiented_mor … (canonical_proj … (eqrel_of_morphism … f) x).
207 #A; #B; #f; #x; napply refl;
210 ndefinition surjective ≝
211 λA,B.λS: qpowerclass A.λT: qpowerclass B.λf:unary_morphism A B.
212 ∀y. y ∈ T → ∃x. x ∈ S ∧ f x = y.
214 ndefinition injective ≝
215 λA,B.λS: qpowerclass A.λf:unary_morphism A B.
216 ∀x,x'. x ∈ S → x' ∈ S → f x = f x' → x = x'.
218 nlemma first_omomorphism_theorem_functions2:
219 ∀A,B.∀f: unary_morphism A B.
220 surjective … (Full_set ?) (Full_set ?) (canonical_proj ? (eqrel_of_morphism … f)).
221 #A; #B; #f; nwhd; #y; #Hy; @ y; @ [ napply I | napply refl]
222 (* bug, prova @ I refl *)
225 nlemma first_omomorphism_theorem_functions3:
226 ∀A,B.∀f: unary_morphism A B.
227 injective … (Full_set ?) (quotiented_mor … f).
228 #A; #B; #f; nwhd; #x; #x'; #Hx; #Hx'; #K; nassumption.
231 nrecord isomorphism (A) (B) (S: qpowerclass A) (T: qpowerclass B) : CProp[0] ≝
232 { iso_f:> unary_morphism A B;
233 f_closed: ∀x. x ∈ S → iso_f x ∈ T;
234 f_sur: surjective … S T iso_f;
235 f_inj: injective … S iso_f