∀ {X Y : AlgebraicGeometry.Scheme} (f : X ⟶ Y) {Z : AlgebraicGeometry.Scheme}
  [inst : AlgebraicGeometry.IsOpenImmersion f] (g : Y ⟶ Z) [inst_1 : AlgebraicGeometry.LocallyOfFiniteType g],
  AlgebraicGeometry.Scheme.Hom.quasiFiniteLocus (CategoryTheory.CategoryStruct.comp f g) =
    (TopologicalSpace.Opens.map f.base).obj (AlgebraicGeometry.Scheme.Hom.quasiFiniteLocus g)