TitleFinite-valued Lukasiewicz modal logic is PSPACE-complete
Publication TypeConference Paper
Year of Publication2011
AuthorsBou F, Cerami M, Esteva F
Conference NameTwenty-second International Joint Conference on Artificial Intelligence (IJCAI 2011)
Conference LocationBarcelona
Pagination774 - 779
Date Published16/07/2011
ISBN Number978-1-57735-516-8

It is well-known that satisfiability (and hence validity) in the minimal classical modal logic is a PSPACE-complete problem. In this paper we consider the satisfiability and validity problems (here they are not dual, although mutually reducible) for the minimal modal logic over a finite Lukasiewicz chain, and show that they also are PSPACE-complete. This result is also true when adding either the Delta operator or truth constants in the language, i.e. in all these cases it is PSPACE- complete.