Towards an Understanding of Hill-Climbing Procedures for SAT

Abstract

Recently several local hill-climbing procedures for propositional satisfiability have been proposed, which are able to solve large and difficult problems beyond the reach of conventional algorithms like Davis-Putnam. By the introduction of some new variants of these procedures, we provide strong experimental evidence to support the conjecture that neither greediness nor randomness is important in these procedures. One of the variants introduced seems to offer significant improvements over earlier procedures. In addition, we investigate experimentally how their performance depends on their parameters. Our results suggest that run-time scales less than simply exponentially in the problem size. 1 Introduction Recently several local hill-climbing procedures for propositional satisfiability have been proposed [4, 3, 11]. Propositional satisfiability (or SAT) is the problem of deciding if there is an assignment for the variables in a propositional formula that makes the formula tr...