Rough membership measure in intuitionistic fuzzy information system

Fuzzy relation is the generalization of the classical binary relation. Based on intuitionistic fuzzy information system, a fuzzy equivalence relation is defined in this paper. Thus, fuzzy approximation space is established in intuitionistic fuzzy information system. And rough membership measure is defined by fuzzy equivalence relation. In addition, a few significant properties of the degree of the roughness of membership are proved., after that an demonstrative case is proposed in intuitionistic fuzzy information system.