The Study On Soft Set

At present soft set theory is new mathematical tools de-veloped which deal with uncertainty problem in many fields.Manyresearchers attach importance to soft set theory because of its richpotential for applications in several directions.This paper mainly studied some aspects of soft set.First,the paper introduces the definition of soft set , fuzzy softset ,and soft set theory and fuzzy soft set theory ,and discusses theapplication of soft set and fuzzy soft set in a decision making problem.Next,in this paper we define fuzzy soft set in another hand throughnested set.In other words,fuzzy soft set is defined by classical softnested set,and the union,intersection,complement of fuzzy soft set aredefined by union,intersection,complement of soft set,so it finished theextension form classical soft sets to fuzzy soft sets .Last,the dual of soft set is defined and the property of soft groupare studied by dual soft set .Then soft subgroup ,normal soft subgroup,image and primary image of soft set are defined and discussed .Atlast,a new relation–soft relation are defined,and the relation of softrelation and equivalence relation is discussed by dual soft set.