∀ {X Y Z : AlgebraicGeometry.LocallyRingedSpace} (f : X ⟶ Z) (g : Y ⟶ Z)
  [H : AlgebraicGeometry.LocallyRingedSpace.IsOpenImmersion f],
  CategoryTheory.Limits.PreservesLimit (CategoryTheory.Limits.cospan g f)
    (AlgebraicGeometry.LocallyRingedSpace.forgetToSheafedSpace.comp
      AlgebraicGeometry.SheafedSpace.forgetToPresheafedSpace)