Non-monotonic reasoning on Beowulf platforms

Non-monotonic logic programming systems, such as the various implementations of Answer Set Programming (ASP), are frequently used to solve problems with large search spaces. In spite of the impressive improvements in implementation technology, the sheer size of realistic computations required to solve problems of interest often makes such problems inaccessible to existing sequential technology. This paper presents some preliminary results obtained in the development of solutions for execution of Answer Set Programs on parallel architectures. We identify different forms of parallelism that can be automatically exploited in a typical ASP execution, and we describe the execution models we have experimented with to take advantage of some of these. Performance results obtained on a Beowulf system are presented.