Peer-to-Peer Query Answering with Inconsistent Knowledge

Decentralized reasoning is receiving increasing attention due to the distributed nature of knowledge on the Web. We address the problem of answering queries to distributed propositional reasoners which may be mutually inconsistent. This paper provides a formal characterization of a prioritized peerto-peer query answering framework that exploits a priority ordering over the peers, as well as a distributed entailment relation as an extension to established work on argumentation frameworks. We develop decentralized algorithms for computing query answers according to distributed entailment and prove their soundness and completeness. To improve the efficiency of query answering, we propose an ordering heuristic that exploits the peers’ priority ordering and empirically evaluate its effectiveness.