A Software Architecture for Knowledge-Based Systems

. The paper introduces a software architecture for the specification and verification of knowledge-based systems combining conceptual and formal techniques. Our focus is component-based specification enabling their reuse. We identify four elements of the specification of a knowledge-based system: a task definition, a problem-solving method, a domain model, and an adapter. We present algebraic specifications and a variant of dynamic logic as formal means to specify and verify these different elements. As a consequence of our architecture we can decompose the overall specification and verification task of the knowledge-based systems into subtasks. We identify different subcomponents for specification and different proof obligations for verification. The use of the architecture in specification and verification improves understandability and reduces the effort for both activities. In addition, its decomposition and modularisation enables reuse of components and proofs. Ther..

Defining a semantics and axiomatization for specifying the reasoning proces of knowledge-based systems

We investigate the formal specification of the dynamic reasoning process of knowledge-based systems. The main contributions of the paper are: defining a formal framework for describing the dynamic reasoning behaviour of knowledge-based systems which unifies existing approaches; defining a semantics for the specification of the dynamic reasoning behaviour of a knowledge-based system within the states as algebra setting that overcomes several shortcomings of the existing approaches; and providing for the first time an axiomatization and proof theory of specification languages for knowledge-based systems. We achieve this by developing the logical language MLPM (Modal Logic of Predicate Modification)