一个粗糙集代数是由一个集合代数加上一对近似算子构成的。本文用公理化方法定义了模糊环境下的近似算子和粗糙集代数系统。证明了若系统(F(U),∩,∪,~,L,H)是一个模糊粗糙集(粗糙模糊集)代数,则其导出的系统(F(U),∩,∪,~,LL,HH)也是模糊粗糙集(粗糙模糊集)代数,同时讨论了特殊类型的模糊粗糙集代数和粗糙模糊集代数与其导出的系统之间的关系。
A rough set algebra is a set algebra with added dual pair of rough approximation operators. In this paper, axiomatic definitions of rough set approximation operators and rough set algebras in fuzzy environment are introduced. It is proved that if a system (F(U), ∩,∪~ ,L,H) is a fuzzy rough set algebra (a rough fuzzy set algebra, respectively), then the derived system (F-(U), ∩,∪~, LL, HH) is also a fuzzy rough set algebra (a rough fuzzy set algebra,respectively). Relationships between special types of fuzzy rough set algebras (rough fuzzy set algebras, respectively) and their producing composed rough set algebras are further examined.