include "logic/cprop.ma".
-nrecord powerset (A: setoid) : Type[1] ≝ { mem_op: unary_morphism1 A CPROP }.
+nrecord powerset (A: setoid) : Type[1] ≝ { mem_op:> unary_morphism1 A CPROP }.
interpretation "powerset" 'powerset A = (powerset A).
[ napply (Ω \sup S)
| napply mk_equivalence_relation1
[ #A; #B; napply (∀x. iff (x ∈ A) (x ∈ B))
- | nnormalize; #x; #x0; napply mk_iff; #H; nassumption
- | nnormalize; #x; #y; #H; #A; napply mk_iff; #K
+ | nwhd; #x; #x0; napply mk_iff; #H; nassumption
+ | nwhd; #x; #y; #H; #A; napply mk_iff; #K
[ napply (fi ?? (H ?)) | napply (if ?? (H ?)) ]
nassumption
- | nnormalize; #A; #B; #C; #H1; #H2; #H3; napply mk_iff; #H4
+ | nwhd; #A; #B; #C; #H1; #H2; #H3; napply mk_iff; #H4
[ napply (if ?? (H2 ?)); napply (if ?? (H1 ?)); nassumption
| napply (fi ?? (H1 ?)); napply (fi ?? (H2 ?)); nassumption]##]
nqed.
interpretation "overlaps" 'overlaps U V = (overlaps ? U V).
-ndefinition intersects ≝ λA.λU,V:Ω \sup A. {x | x ∈ U ∧ x ∈ V }.
- #a; #a'; #H; napply mk_iff; *; #H1; #H2
- [ napply (. ((H^-1‡#)‡(H^-1‡#))); nnormalize; napply conj; nassumption
- | napply (. ((H‡#)‡(H‡#))); nnormalize; napply conj; nassumption]
+ndefinition intersects ≝ λA:Type[0].λU,V:A → CProp[0]. λx. U x ∧ V x.
+
+interpretation "intersects" 'intersects U V = (intersects ? U V).
+
+(* dovrebbe essere un binario? *)
+ndefinition intersects_ok: ∀A. Ω \sup A → Ω \sup A → Ω \sup A.
+ #A; #U; #V; napply mk_powerset; napply mk_unary_morphism1
+ [ napply (intersects ? (mem_op ? U) (mem_op ? V))
+ | #a; #a'; #H; napply mk_iff; *; #H1; #H2
+ [ nwhd; napply (. ((H^-1‡#)‡(H^-1‡#))); nwhd; napply conj; nassumption
+ | nwhd; napply (. ((H‡#)‡(H‡#))); nwhd; napply conj; nassumption]
+nqed.
+
+unification hint 0 (∀A.∀U,V: Ω \sup A.∀w.(λx,y.True)
+ (intersects A U V w) (fun11 ?? (mem_op ? (intersects_ok A U V)) w)).
+
+nlemma test: ∀A. ∀U,V: Ω \sup A. ∀x,x':A. x=x' → (U ∩ V) x → (U ∩ V) x'.
+ #A; #U; #V; #x; #x'; #H; #p;
+ nwhd in ⊢ (? ? % % ?);
+ (* l'unification hint non funziona *)
+ nchange with (? ∈ (intersects_ok ? ? ?));
+ napply (. (†H^-1));
+ nassumption.
nqed.
-
-(*interpretation "intersects" 'intersects U V = (intersects ? U V).*)
(*
ndefinition union ≝ λA.λU,V:Ω \sup A. {x | x ∈ U ∨ x ∈ V }.
ndefinition singleton ≝ λA:setoid.λa:A.{b | a=b}.
-interpretation "singleton" 'singl a = (singleton ? a).*)
\ No newline at end of file
+interpretation "singleton" 'singl a = (singleton ? a).*)
+
+(*
+(* qui non funziona una cippa *)
+ndefinition image: ∀A,B. (carr A → carr B) → Ω \sup A → Ω \sup B ≝
+ λA,B:setoid.λf:carr A → carr B.λSa:Ω \sup A.
+ {y | ∃x. x ∈ Sa ∧ eq_rel (carr B) (eq B) ? ?(*(f x) y*)}.
+ ##[##2: napply (f x); ##|##3: napply y]
+ #a; #a'; #H; nwhd; nnormalize; (* per togliere setoid1_of_setoid *) napply (mk_iff ????);
+ *; #x; #Hx; napply (ex_intro … x)
+ [ napply (. (#‡(#‡#)));
+
+ndefinition counter_image: ∀A,B. (A → B) → Ω \sup B → Ω \sup A ≝
+ λA,B,f,Sb. {x | ∃y. y ∈ Sb ∧ f x = y}.
+*)