∀ {ι : Type u} (R : ι → CommRingCat) (X : AlgebraicGeometry.Scheme)
  (f : AlgebraicGeometry.Spec (CommRingCat.of ((i : ι) → ↑(R i))) ⟶ X) (i : ι),
  AlgebraicGeometry.pointsPi R X f i =
    CategoryTheory.CategoryStruct.comp
      (AlgebraicGeometry.Spec.map (CommRingCat.ofHom (Pi.evalRingHom (fun x => ↑(R x)) i))) f