. bla Keywords: Concurrent rewriting, -calculus, abstract interpretation, inheritance anomaly, reusability. 1 Introduction Responsible for this is the synchronization code, which implements the autonomy of objects. Thus, synchronization code again is responsible for the incompatibility of concurrency and inheritance which has been analyzed by Matsuoka and Yonezawa, called the inheritance anomaly. We would like to have reuse of code, and this means not necessarily inheritance, more precisely inheritance alone, to us. Thus, we have developed for the reuse of classes a set of reuse concepts and constructs for Maude and we have demonstrated that those set of reuse constructs is able to circumvent the inheritance anomaly [LLNW95]. However, one is not generally interested in reuse of code, but inheritance of properties. In a well- structured design of the class hierarchy should be set up in a way, such that the reuse relations between the classes have some semantic connotation, i.e., th..