A SAT approach to clique-width

  • Authors:
  • Marijn J. H. Heule;Stefan Szeider

  • Affiliations:
  • Department of Computer Sciences, The University of Texas at Austin;Institute of Information Systems, Vienna University of Technology, Vienna, Austria

  • Venue:
  • SAT'13 Proceedings of the 16th international conference on Theory and Applications of Satisfiability Testing
  • Year:
  • 2013

Quantified Score

Hi-index 0.00

Visualization

Abstract

Clique-width is a graph invariant that has been widely studied in combinatorics and computer science. However, computing the clique-width of a graph is an intricate problem, the exact clique-width is not known even for very small graphs. We present a new method for computing the clique-width of graphs based on an encoding to propositional satisfiability (SAT) which is then evaluated by a SAT solver. Our encoding is based on a reformulation of clique-width in terms of partitions that utilizes an efficient encoding of cardinality constraints. Our SAT-based method is the first to discover the exact clique-width of various small graphs, including famous graphs from the literature as well as random graphs of various density. With our method we determined the smallest graphs that require a small pre-described clique-width.