基于μ-演算的一阶谓词界程逻辑，用谓词变量构造不动点公式，方便描述闭环系统的性质，公式语义简洁．-Based on μ-calculus, the predicate variable is used to construct the fixed point formula, which is convenient to describe the properties of the closed-loop system and the semantics of the formula is co