Abstract
We present a method and an associated system, called MathCheck, that embeds the functionality of a computer algebra system (CAS) within the inner loop of a conflict-driven clause-learning SAT solver. SAT+CAS systems, a la MathCheck, can be used as an assistant by mathematicians to either counterexample or finitely verify open universal conjectures on any mathematical topic (e.g., graph and number theory, algebra, geometry, etc.) supported by the underlying CAS system. Such a SAT+CAS system combines the efficient search routines of modern SAT solvers, with the expressive power of CAS, thus complementing both. The key insight behind the power of the SAT+CAS combination is that the CAS system can help cut down the search-space of the SAT solver, by providing learned clauses that encode theory-specific lemmas, as it searches for a counterexample to the input conjecture (just like the T in DPLL(T)). In addition, the combination enables a more efficient encoding of problems than a pure Boolean representation.
In this paper, we leverage the graph-theoretic capabilities of an open-source CAS, called SAGE. As case studies, we look at two long-standing open mathematical conjectures from graph theory regarding properties of hypercubes: the first conjecture states that any matching of any d-dimensional hypercube can be extended to a Hamiltonian cycle; and the second states that given an edge-antipodal coloring of a hypercube, there always exists a monochromatic path between two antipodal vertices. Previous results have shown the conjectures true up to certain low-dimensional hypercubes, and attempts to extend them have failed until now. Using our SAT+CAS system, MathCheck, we extend these two conjectures to higher-dimensional hypercubes. We provide detailed performance analysis and show an exponential reduction in search space via the SAT+CAS combination relative to finite brute-force search.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Notes
- 1.
All code+data is available at https://bitbucket.org/ezulkosk/sagesat.
- 2.
For notational convenience, we often use existential quantifiers when defining constraints; these are unrolled in the implementation. We only deal with finite graphs.
- 3.
We were unable to find the original source of the results for \(d\le 4\), however the result is asserted in [10]. We also verified these results using our system.
- 4.
References
Audemard, G., Simon, L.: Predicting learnt clauses quality in modern SAT solvers. IJCAI 9, 399–404 (2009)
Barrett, C., Conway, C.L., Deters, M., Hadarean, L., Jovanović, D., King, T., Reynolds, A., Tinelli, C.: CVC4. In: Gopalakrishnan, G., Qadeer, S. (eds.) CAV 2011. LNCS, vol. 6806, pp. 171–177. Springer, Heidelberg (2011)
Biere, A., Heule, M.J.H., van Maaren, H., Walsh, T.(eds.): Handbook of Satisfiability. FAIA, vol. 185. IOS Press (February 2009)
Bouton, T., de Oliveira, D.C.B., Déharbe, D., Fontaine, P.: veriT: an open, trustable and efficient SMT-solver. In: CADE (2009)
Chen, Y-C., Li, K-L.: Matchings extend to perfect matchings on hypercube networks. In: IMECS, vol. 1. Citeseer (2010)
de Moura, L., Bjørner, N.S.: Z3: an efficient SMT solver. In: Ramakrishnan, C.R., Rehof, J. (eds.) TACAS 2008. LNCS, vol. 4963, pp. 337–340. Springer, Heidelberg (2008)
Devos, M., Norine, S.: Edge-antipodal Colorings of Cubes. http://garden.irmacs.sfu.ca/?q=op/edge_antipodal_colorings_of_cubes
Dooms, G., Deville, Y., Dupont, P.E.: CP(Graph): introducing a graph computation domain in constraint programming. In: van Beek, P. (ed.) CP 2005. LNCS, vol. 3709, pp. 211–225. Springer, Heidelberg (2005)
Feder, T., Subi, C.: On hypercube labellings and antipodal monochromatic paths. Discrete Appl. Math. 161(10), 1421–1426 (2013)
Fink, J.: Perfect matchings extend to hamilton cycles in hypercubes. J. Comb. Theor. B 97(6), 1074–1076 (2007)
Fink, J.: Connectivity of matching graph of hypercube. SIDMA 23(2), 1100–1109 (2009)
Ganesh, V., Dill, D.L.: A decision procedure for bit-vectors and arrays. In: Damm, W., Hermanns, H. (eds.) CAV 2007. LNCS, vol. 4590, pp. 519–531. Springer, Heidelberg (2007)
Ganesh, V., O’Donnell, C.W., Soos, M., Devadas, S., Rinard, M.C., Solar-Lezama, A.: Lynx: a programmatic sat solver for the rna-folding problem. In: Cimatti, A., Sebastiani, R. (eds.) SAT 2012. LNCS, vol. 7317, pp. 143–156. Springer, Heidelberg (2012)
Gebser, M., Janhunen, T., Rintanen, J.: SAT modulo graphs: acyclicity. In: Fermé, E., Leite, J. (eds.) JELIA 2014. LNCS, vol. 8761, pp. 137–151. Springer, Heidelberg (2014)
Gregor, P.: Perfect matchings extending on subcubes to hamiltonian cycles of hypercubes. Discrete Math. 309(6), 1711–1713 (2009)
Heule, M.J.H., Hunt, W.A., Wetzler, N.: Trimming while checking clausal proofs. In: FMCAD, pp. 181–188. IEEE (2013)
Holm, J., De Lichtenberg, K., Thorup, M.: Poly-logarithmic deterministic fully-dynamic algorithms for connectivity, minimum spanning tree, 2-edge, and biconnectivity. J. ACM (JACM) 48(4), 723–760 (2001)
Konev, B., Lisitsa, A.: A SAT attack on the Erdős discrepancy conjecture. In: SAT (2014)
Nieuwenhuis, R., Oliveras, A., Tinelli, C.: Abstract DPLL and abstract DPLL modulo theories. In: Baader, F., Voronkov, A. (eds.) LPAR 2004. LNCS (LNAI), vol. 3452, pp. 36–50. Springer, Heidelberg (2005)
Ruskey, F., Savage, C.: Hamilton cycles that extend transposition matchings in Cayley graphs of \(S_n\). SIDMA 6(1), 152–166 (1993)
Sebastiani, R.: Lazy satisfiability modulo theories. J. Satisfiability Boolean Model. Comput. 3, 141–224 (2007)
Soh, T., Le Berre, D., Roussel, S., Banbara, M., Tamura, N.: Incremental SAT-based method with native boolean cardinality handling for the hamiltonian cycle problem. In: Fermé, E., Leite, J. (eds.) JELIA 2014. LNCS, vol. 8761, pp. 684–693. Springer, Heidelberg (2014)
Stein, W.A.(et al).: Sage Mathematics Software (Version 6.3) (2010)
Thurley, M.: sharpSAT – counting models with advanced component caching and implicit BCP. In: Biere, A., Gomes, C.P. (eds.) SAT 2006. LNCS, vol. 4121, pp. 424–429. Springer, Heidelberg (2006)
Velev, M.N., Gao, P.: Efficient SAT techniques for absolute encoding of permutation problems: application to hamiltonian cycles. In: SARA (2009)
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2015 Springer International Publishing Switzerland
About this paper
Cite this paper
Zulkoski, E., Ganesh, V., Czarnecki, K. (2015). MathCheck: A Math Assistant via a Combination of Computer Algebra Systems and SAT Solvers. In: Felty, A., Middeldorp, A. (eds) Automated Deduction - CADE-25. CADE 2015. Lecture Notes in Computer Science(), vol 9195. Springer, Cham. https://doi.org/10.1007/978-3-319-21401-6_41
Download citation
DOI: https://doi.org/10.1007/978-3-319-21401-6_41
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-21400-9
Online ISBN: 978-3-319-21401-6
eBook Packages: Computer ScienceComputer Science (R0)