“…Remark 2.6 About the notation and nomenclature used in Definition 2.5, we point out that in some papers (see e.g., [9,14,17]) the left R-topology (respectively, the right R-topology) is called "upper topology" (respectively, "lower topology"). However, that nomenclature may cause confusion when compared to the traditional one in the domain theory (see [15]), where, if a partial order is fixed on a set X , then usually the upper topology is the least topology such that all the principal lower sets {y ∈ X : y x}, x ∈ X , are closed.…”