English
An order isomorphism between Heyting algebras induces a Heyting homomorphism class.
Русский
Изоморфизм порядка между Хейтинговыми алгебрами индуцирует класс гомоморфизмов Хейтинга.
LaTeX
$$$ \text{If } F \text{ is an order isomorphism class between } α,β, \text{ then } F \text{ induces a HeytingHomClass.}$$$
Lean4
instance (priority := 100) toHeytingHomClass [BiheytingAlgebra α] {_ : BiheytingAlgebra β} [BiheytingHomClass F α β] :
HeytingHomClass F α β :=
{ ‹BiheytingHomClass F α β› with
map_bot := fun f => by rw [← @sdiff_self α _ ⊤, ← sdiff_self, BiheytingHomClass.map_sdiff] }
-- See note [lower instance priority]