English
There is a canonical algebra homomorphism from S to the stalk of the pushforward structure sheaf, describing the algebra structure on the pushforward stalk.
Русский
Существует канонический алгебра-гомоморфизм из S в stalk пушфорвардной структуры оболочки, описывающий алгебраическую структуру stalk.
LaTeX
$$$S \to_{\text{AlgHom}} (\Spec.topMap \cdot).stalk p$$$
Lean4
/-- This is the `AlgHom` version of `toPushforwardStalk`, which is the map `S ⟶ (f∗ 𝒪ₛ)ₚ` for some
algebra `R ⟶ S` and some `p : Spec R`.
-/
@[simps!]
def toPushforwardStalkAlgHom :
S →ₐ[R] (Spec.topMap (CommRingCat.ofHom (algebraMap R S)) _* (structureSheaf S).1).stalk p :=
{ (StructureSheaf.toPushforwardStalk (CommRingCat.ofHom (algebraMap R S)) p).hom with commutes' := fun _ => rfl }