Known and new classes of generalized Horn formulae with polynomial recognition and SAT testing

摘要

In this paper we study several classes of Boolean formulae which generalize Horn formulae while preserving one of their main properties, namely the fact that satisfiability is decidable in polynomial time. We compare the known classes with respect to inclusion and define a hierarchy of new classes, which properly contains some of the known classes. (c) 2005 Elsevier B.V. All rights reserved.