∀ (X : AlgebraicGeometry.LocallyRingedSpace) (U : (TopologicalSpace.Opens ↑↑X.toPresheafedSpace)ᵒᵖ)
  (x y : ↑(X.presheaf.1 U)),
  (↑{ toFun := 0, map_one' := ⋯, map_mul' := ⋯ }).toFun (x + y) =
    (↑{ toFun := 0, map_one' := ⋯, map_mul' := ⋯ }).toFun (x + y)