Axiomatic approaches to rough approximation operators on complete completely distributive lattices

We proposed a pair of rough approximation operators on a complete completely distributive lattice (CCD lattice for short) in 2015. In this paper, we further discuss its properties and study the axiomatic approaches to the rough approximation operators. Through these axioms, fuzzy rough approximation operators can be seen as special cases of rough approximation operators on a CCD lattice. We also discuss the axiomatic approaches to generalized rough sets on CCD lattices.