On Subtyping Inheritance and Inference Rules in Object-Oriented Z
面向对象Z的子类型继承和推理规则

The inheritance relation of COOZ is discussed. It is divided into increasing inheritance and subtyping inheritance. The latter is studied and a behavioral subtyping inheritance is defined, by which the specification inheritance and its inference rules are defined. The soundness of the method is proved. The offered method is constructive compared with that of E. Cusack and is more flexible than that of Liskov et al.