ExClaim: a language for operationalizing CommonKADS expertise models using description logics

This report presents E x Claim, a hybrid language for knowledge representation and reasoning. Developed as an operationalization language for the KADS knowledge based systems development methodology, E x Claim has a meta-level architecture: it structures the knowledge on three levels, namely the domain, inference and task level. An extension of a description logic is used for implementing the domain level. The inference and task levels are procedural and support non-determinism (inferences and tasks being backtrackable). This in turn requires a non-monotonic domain level. Description logics (term subsumption languages) offer a set of inference services (not available in other KR languages) which are extremely useful in knowledge modelling. Such inference services include domain-level deduction, semantic consistency verification and automatic classification of concepts. Note that most of the existing KBS development tools and environments do not provide any facilities for model consis..