TFL: an algebraic language to specify the dynamic behaviour of knowledge-based systems

TFL the Task Formal Language has been developed for integrating the static and dynamic aspects of Knowledge Based Systems This paper focuses on the formal speci cation of dynamic behaviour Although fundamental in Knowledge Based System the strategic reasoning was rather neglected until now by the existing formal speci cations Most languages were generally more focused on the domain and problem solving knowledge speci cation than on the control The formalisation presented here di ers from previous ones in several aspects First a di erent representation of dynamic knowledge is proposed TFL is based on Algebraic Data Types as opposed to dynamic or temporal logic Second dynamic strategic reasoning is emphasised whereas existing languages only o er to specify algorithmic control Then TFL does not only provide the speci cation of the problem solving knowledge of the object system but also of its strategic knowledge Finally the dynamic knowledge of the meta system itself is also speci ed Moreover modularisation is another important feature of the presented language