Or-Parallelism within Tabling

Abstract. One important advantage of logic programming is that it al-lows the implicit exploitation of parallelism. Towards this goal, we sug-gest that or-parallelism can be eciently exploited in tabling systems and propose two alternative approaches, Or-Parallelism within Tabling (OPT) and Tabling within Or-Parallelism (TOP). We concentrate on the fundamental concepts of an environment copying based model to implement the OPT approach and introduce the data structures and algorithms necessary to extend the YapOr Or-Parallel system, in order to obtain a parallel tabling system