Constructive and Algebraic Methods of Approximation Operators over Two Universes
Weizhi Wang · Mohu xitong yu shuxue · 2008
Constructive and axiomatic approaches of the theory of rough sets were developed in paper [1], and they were studied by using the binary relation over singleton universes U. This paper generalize two methods to the rough sets over two universes when using the binary relation between universes U and V, it is a generalization of the conclusion in literature [1].