{n : Type v} →
  (S : AlgebraicGeometry.Scheme) →
    {X : AlgebraicGeometry.Scheme} →
      [inst : X.Over S] → { f // AlgebraicGeometry.Scheme.Hom.IsOver f S } ≃ (n → ↑(X.presheaf.obj (Opposite.op ⊤)))