English
For an open immersion f and X, Y, invApp assigns a morphism X.presheaf.obj(op U) → Y.presheaf.obj(op (opensFunctor f).obj U).
Русский
Для открытого вложения f и X, Y invApp задаёт морфизм X.presheaf.obj(op U) → Y.presheaf.obj(op (opensFunctor f).obj U).
LaTeX
$$$\text{invApp} : (U:\mathrm{Opens}(X)) \to X.presheaf(U) \to Y.presheaf(op( opensFunctor f(U))).$$$
Lean4
/-- For an open immersion `f : X ⟶ Y` and an open set `U ⊆ X`, we have the map `X(U) ⟶ Y(U)`. -/
noncomputable def invApp (U : Opens X) : X.presheaf.obj (op U) ⟶ Y.presheaf.obj (op (opensFunctor f |>.obj U)) :=
PresheafedSpace.IsOpenImmersion.invApp f U