English
Pull back a CoheytingAlgebra along an injection, preserving top, bottom, negation and sdiff. Domain inherits a CoheytingAlgebra.
Русский
Вытягивание по инъекции для коейтинговой алгебры сохраняет ⊤, ⊥, отрицание и разность; область определения наследует коейтинговую алгебру.
LaTeX
$$$\text{Function.Injective.coheytingAlgebra}(f,hf,map\_sup,map\_inf,map\_top,map\_bot,map\_hnot,map\_sdiff) : \text{CoheytingAlgebra } \alpha$$$
Lean4
/-- Pullback a `CoheytingAlgebra` along an injection. -/
protected abbrev coheytingAlgebra [Max α] [Min α] [Top α] [Bot α] [HNot α] [SDiff α] [CoheytingAlgebra β] (f : α → β)
(hf : Injective f) (map_sup : ∀ a b, f (a ⊔ b) = f a ⊔ f b) (map_inf : ∀ a b, f (a ⊓ b) = f a ⊓ f b)
(map_top : f ⊤ = ⊤) (map_bot : f ⊥ = ⊥) (map_hnot : ∀ a, f (¬a) = ¬f a) (map_sdiff : ∀ a b, f (a \ b) = f a \ f b) :
CoheytingAlgebra α :=
{ __ := hf.generalizedCoheytingAlgebra f map_sup map_inf map_bot map_sdiff
__ := ‹Top α›
__ := ‹HNot α›
le_top := fun a => by
change f _ ≤ _
rw [map_top]
exact le_top,
top_sdiff := fun a => hf <| by rw [map_sdiff, map_hnot, map_top, top_sdiff'] }
-- See note [reducible non-instances]