- A:?, B,C : 𝛀^A ⊢
- fun21 …
- (mk_binary_morphism1 …
- (λS,S':qpowerclass_setoid A.S ∩ S')
- (prop21 … (intersect_ok'' A))) B C
- ≡ intersect ? B C.
+ A:setoid, B,C : 𝛀^A;
+ R ≟ (mk_binary_morphism1 (ext_powerclass_setoid A) (ext_powerclass_setoid A) (ext_powerclass_setoid A)
+ (λS,S':carr1 (ext_powerclass_setoid A).
+ mk_ext_powerclass A (S∩S') (ext_prop A (intersect_is_ext ? S S')))
+ (prop21 … (intersect_is_ext_morph A))) ,
+ BB ≟ (ext_carr ? B),
+ CC ≟ (ext_carr ? C)
+ (* ------------------------------------------------------*) ⊢
+ ext_carr A
+ (fun21
+ (ext_powerclass_setoid A)
+ (ext_powerclass_setoid A)
+ (ext_powerclass_setoid A) R B C) ≡
+ intersect (carr A) BB CC.