Extension of some definitions of Aggregations inhesitant fuzzy concepts

The definition of some subjects in hesitant fuzzy set (HFS) Theory will be addressed in this paper. First, some basic definitionsof special hesitant fuzzy sets are stated by generalizing the definitions of fuzzy set to HFS related to different types of defuzzificationmethod of fuzzy sets; also generalization of the intuition fuzzy sets to HFS, called IHFS, will be also addressed.