Fuzzy set with three kinds of negations in fuzzy knowledge processing

In this paper, the negative relation in fuzzy information is distinguished contradictory negative relation and opposite negative relation, and a character of fuzzy information is discovered that if two opposite concepts are fuzzy concepts, there must exist a “medium” fuzzy concept between them, vice versa. Therefore, we proposed that negative relation in fuzzy information include contradictory negative relation, opposite negative relation and medium negative relation, and that formalization definition of them. Based on this cognition, we defined a new fuzzy set FScom with contradictory negation, opposite negation and medium negation, and discussed characteristics of FScom, operations and their properties in FScom.