(r,s)(r,s)-Fuzzy FF-open sets and (r,s)(r,s)-fuzzy FF-closed spaces

In this paper, we introduce the concepts of (r,s)(r,s)-fuzzy FF-open and (r,s)(r,s)-fuzzy FF-closed sets in double fuzzy topological spaces. We used them to explain the notions of (r,s)(r,s)-fuzzy FF-closed spaces. Also, we give some characterization of (r,s)(r,s)-fuzzy FF-closeness in terms of fuzzy filterbasis.