hostuart @ t.qut.edu.au As model-based formal methods (e.g. VDM, Z) are becoming popular for the development of safety-critical and complex systems in industry, automatic transformation from formal speci cations to programs is an ideal and e cient approach to software production. However, it is impossible in general for this transformation to be fully automatic, because of the language of rst order logic used for speci cation is not decidable. This paper uses VDM (Vienna Development Method) as an example to investigate this di culty, and proposes an approach to address the problem. Rules for automatically transforming abstract level VDM specications are described, and further transformation at a detailed level is discussed. Finally, further work towards the construction of a rule-based software system to support the transformation from VDM speci cations to programs in general is addressed. 1.

In this paper we suggest a three-language (3L) paradigm for building the program generator models. The basis of the paradigm is a relationship model of the specification, scripting and target languages. It is not necessary that all three languages would be the separate ones. We consider some internal relationship (roles) between the capabilities of a given language for specifying, scripting (gluing) and describing the domain functionality. We also assume that a target language is basic. We introduce domain architecture (functionality) with the generic components usually composed using the scripting and target languages. The specification language is for describing user's needs for the domain functionality to be extracted from the system. We present the framework for implementing the 3L paradigm and some results from the experimental systems developed for a validation of the approach. Key words: specification language, scripting language, target language, generic component, program g...