Speculative Constraint Processing in Multi-agent Systems

In this paper, we extend our framework of speculative computation in multi-agent systems by using default constraints. In research on multi-agent systems, handling incomplete information due to communication failure or due to other agents’ delay in communication, is a very important issue. For a solution to this problem, we previously proposed speculative computation based on abduction in the context of master-slave multi-agent systems and gave a procedure in abductive logic programming. In the proposal, a master agent prepares a default value for a yes/no question in advance and it performs speculative computation using the default without waiting for a reply to the question. This computation is effective unless the contradictory reply to the default is returned. In this paper, we formalize speculative constraint processing and propose a correct procedure for such computation so that we can handle not only yes/no questions, but also more general types of questions.