中文摘要：

变精度覆盖粗糙集模型是在放宽了覆盖标准的前提下给出的，因而导致近似算子发生了变化．在介绍了覆盖粗糙集模型和变精度覆盖粗糙集模型的概念的基础上，给出并证明了变精度覆盖粗糙集模型的近似算子的几个性质，即定理1、定理2、定理3及其推论．

英文摘要：

The model of variable precision covering rough set is proposed under certain conditions of relaxing coverage standard which yields diversification of the approximation operators.After introducing the concepts on models of covering rough set and variable precision covering rough set.Several properties of approximation operators are put forward and proved,that is theorem 1,theorem 2 and the related corollaries.