∀ {P : CategoryTheory.MorphismProperty AlgebraicGeometry.Scheme} {Q : AlgebraicGeometry.AffineTargetMorphismProperty}
  [AlgebraicGeometry.HasAffineProperty P Q],
  (∀ {X Y : AlgebraicGeometry.Scheme} (f : X ⟶ Y) [inst : AlgebraicGeometry.IsAffine Y] (𝒰 : X.OpenCover),
      Q f ↔ ∀ (i : 𝒰.I₀), Q (CategoryTheory.CategoryStruct.comp (𝒰.f i) f)) →
    AlgebraicGeometry.IsZariskiLocalAtSource P