On $L$-double fuzzy rough sets

Abstract

ur aim of this paper is to introduce the concept of $L$-double fuzzy rough sets in which<br />both constructive and axiomatic approaches are used. In constructive approach, a pair<br />of $L$-double fuzzy lower (resp. upper) approximation operators is defined and the basic properties of them are studied.<br />From the viewpoint of the axiomatic approach, a set of axioms is constructed to characterize the $L$-double fuzzy upper (resp. lower) approximation of $L$-double fuzzy rough sets. Finally, from $L$-double fuzzy approximation operators, we generated Alexandrov $L$-double fuzzy topology.