Verification of dynamic epistemic properties in multi-agent systems
Marina Bagić Babac · 2009
One of the major application areas of reasoning about knowledge are multi-agent systems (MAS). The paradigm of MAS has been employed successfully in several fields, including philosophy, economics and software engineering. MAS formalism enables us to abstract a system from unnecessary details and to focus on communication and cooperation among agents in the system. This thesis is concerned with the problems of MAS specification and verification, with the emphasis on their dynamic epistemic properties. Epistemic transition system (ETS) is introduced to present an agent as the smallest unit in a multi-agent system. Being composed of a set of well defined ETSs, MAS builds the epistemic synchronous product (ESP) describing the formal model for a multi-agent system. A special extension of Action computation tree logic with unless operator (ACTLW) for epistemic reasoning (ACTLW-ER) is then used for model checking dynamic epistemic properties of MAS. The epistemic operators are added to ACTLW for that purpose. They are implemented by symbolic model checking algorithms using binary decision diagrams. A set of communication protocols are provided to explain the practical meaning of the theoretical approach. Each example provides with the specification, encoding, verification steps and experimental results are given to conclude.