∀ {X Y : AlgebraicGeometry.Scheme} (e : X ≅ Y) (x : ↥X) (y : ↑(X.presheaf.stalk (e.inv (e.hom x)))),
  (CategoryTheory.ConcreteCategory.hom (AlgebraicGeometry.Scheme.Hom.stalkMap e.hom x))
      ((CategoryTheory.ConcreteCategory.hom (AlgebraicGeometry.Scheme.Hom.stalkMap e.inv (e.hom x))) y) =
    (CategoryTheory.ConcreteCategory.hom (X.presheaf.stalkCongr ⋯).hom) y