On rough multi-granularity soft sets and its application in decision making

In this paper we proposed the concept of optimistic rough multi-granularity soft set and pessimistic rough multi-granularity soft set. Basic properties of rough multi-granularity soft sets are presented. Furthermore, we compared the difference between rough multi-granularity soft sets and rough soft sets showed by some illustrative examples. Finally, an algorithm for decision making problem is proposed. We also give an example to illustrate the validity of this kind of method.