Comparing Formal Specification . . .

This paper presents a comparison between eight specification languages discussed during the Workshop on Formal Specification Techniques for Complex Reasoning Systems held in Vienna during the ECAI'92 conference. The languages as discussed here possess many important common characteristics, but also differ substantially. The analysis discussed here departs from looking at the purposes of the presented languages (Section 1). The comparison in Section 2 focuses on the way of dealing with heuristic knowledge in the specification of the common example task. In Section 3 some differences between the languages are discussed: expressive power� the way of specifying control knowledge� layering of the system architecture. In Section 4 we identify where already a certain consensus can be found� points are discussed that are in common for most of the languages: modularity� local declarativeness� multi-level view on a specification� distinct speci cation of static and dynamic aspects� separation of generic and domain-specific parts of a specification� object-meta distinctions in specifications� the level of specification. Moreover, in Section 4.2 the major open problems are presented. Partially funded by the ESPRIT Programme of the of the European Communities as projec