Theories of fuzzy sets and rough sets are different and complementary generalizations of classical set theory, both of
them are motivated by practical needs to manage and process uncertainty information. The aim of this paper is to study the
relationship between fuzzy sets and rough sets from the view of logic. A new implication operation of rough sets is
constructed, and the rough sets semantics of residuated based fuzzy logic system is presented.
logic with t-norm based semantics, i.e. where the
conjunction connective is interpreted by a t-norm and the
implication operator by its residuum. Hajek [2] introduces
a logic system, named BL, which is the logic of all
continuous t-norms and of their residua. Esteva et al. in
Ref. [3] propose monoidal t-norm based logic (MTL), and
conjecture that MTL is the logic of left-continuous t-norms
and of their residuals. This conjecture was shown to be
true in Ref. [4]. The fuzzy logic system the logic of
nilpotent minimum (NM) is an important schematic
extension of MTL, and further studies in many literatures
(see Refs. [5–6]).