Invertible approximation operators of generalized rough sets and fuzzy rough sets
This paper studies the classes of rough sets and fuzzy rough sets. We discuss the invertible lower and upper approximations and present the necessary and sufficient conditions for the lower approximation to coincide with the upper approximation in both rough sets and fuzzy rough sets. We also study the mathematical properties of a fuzzy rough set induced by a cyclic fuzzy relation.
rough set fuzzy rough set cyclic fuzzy relation invertible mapping mapping