Effective incorporation of double look-ahead procedures

Abstract

We introduce an adaptive algorithm to control the use of the double look-ahead procedure. This procedure sometimes enhances the performance of look-ahead based satisfiability solvers. Current use of this procedure is driven by static heuristics. Experiments show that over a wide variety of instances, different parameter settings result in optimal performance. Moreover, a strategy that yields fast performance on one particular class of instances may cause a significant slowdown on other families. Using a single adaptive strategy, we accomplish performances close to the optimal performances reached by the various static settings. On some families, we clearly outperform even the fastest performance based on static heuristics. This paper provides a description of the algorithm and a comparison with the static strategies. This method is incorporated in march-dl, satz, and kcnfs. Also, the dynamic behavior of the algorithm is illustrated by adaptation plots on various benchmarks. © Springer-Verlag Berlin Heidelberg 2007.