The complexity of approximations for epistemic synthesis (extended abstract)

Epistemic protocol specifications allow programs, for settings in which multiple agents act with incomplete information, to be described in terms of how actions are related to what the agents know. They are a variant of the knowledge-based programs of Fagin et al [Distributed Computing, 1997], motivated by the complexity of synthesizing implementations in that framework. The paper proposes an approach to the synthesis of implementations of epistemic protocol specifications, that reduces the problem of finding an implementation to a sequence of model checking problems in approximations of the ultimate system being synthesized. A number of ways to construct such approximations is considered, and these are studied for the complexity of the associated model checking problems. The outcome of the study is the identification of the best approximations with the property of being PTIME implementable.Comment: In Proceedings SYNT 2015, arXiv:1602.0078

Constructing Finite State Implementations of Knowledge-Based Programs with Perfect Recall (Extended Abstract)

) Ron van der Meyden Computing Science University of Technology, Sydney PO Box 123, Broadway NSW 2007 Australia email: [email protected] Abstract. Knowledge-based programs have been proposed as an abstract formalism for the design of multi-agent protocols, based on the idea that an agent's actions are a function of its state of knowledge. The key questions in this approach concern the relationship between knowledge-based programs and their concrete implementations, in which the actions are a function of the agents' local states. In previous work we have shown that with respect to a perfect recall semantics for knowledge, finite state implementations of knowledge-based programs do not always exist. Indeed, determining the existence of such an implementation is undecidable. However, we also identified a sufficient condition under which the existence of a finite state implementation is guaranteed, although this sufficient condition is also undecidable. We show in this paper that there ..

Arrows for knowledge-based circuits

Knowledge-based programs (KBPs) are a formalism for directly relating agents' knowledge and behaviour in a way that has proven useful for specifying distributed systems. Here we present a scheme for compiling KBPs to executable automata in finite environments with a proof of correctness in Isabelle/HOL. We use Arrows, a functional programming abstraction, to structure a prototype domain-specific synchronous language embedded in Haskell. By adapting our compilation scheme to use symbolic representations we can apply it to several examples of reasonable size