English
Given an isomorphism of topological spaces and a morphism of presheaves, the isomorphically transported pushforward acts by composing the maps as described by the isomorphism.
Русский
Приизложение изоморфизма пространств и морфизм пресшефа перемещает pushforward согласно изоморфизму.
LaTeX
$$(toPushforwardOfIso H₁ H₂).app U = F.map (eqToHom ...) ≫ H₂.app (op ((Opens.map H₁.inv).obj (unop U)))$$
Lean4
@[simp]
theorem toPushforwardOfIso_app {X Y : TopCat} (H₁ : X ≅ Y) {ℱ : X.Presheaf C} {𝒢 : Y.Presheaf C} (H₂ : H₁.hom _* ℱ ⟶ 𝒢)
(U : (Opens X)ᵒᵖ) :
(toPushforwardOfIso H₁ H₂).app U =
ℱ.map (eqToHom (by simp [Opens.map, Set.preimage_preimage])) ≫ H₂.app (op ((Opens.map H₁.inv).obj (unop U))) :=
by simp [toPushforwardOfIso, Adjunction.homEquiv_unit]