In this paper, the properties of general fuzzy approximation operators are studied, and the concept of composition of two general fuzzy approximation spaces in the rough set theory is given. The relationships between the approximation operators in the composite space and in the two fuzzy approximation spaces are discussed. It is proved that the approximation operators in the composite space are just the composition of the approximation operators in the two fuzzy approximation spaces.
['Ju-Sheng Mi', 'Wenxiu Zhang']
Composition of General Fuzzy Approximation Spaces