SAT4J: a SATisfiability library for Java.

    /*******************************************************************************
    * SAT4J: a SATisfiability library for Java Copyright (C) 2004-2008 Daniel Le Berre
    *
    * All rights reserved. This program and the accompanying materials
    * are made available under the terms of the Eclipse Public License v1.0
    * which accompanies this distribution, and is available at
    * http://www.eclipse.org/legal/epl-v10.html
    *
    * Alternatively, the contents of this file may be used under the terms of
    * either the GNU Lesser General Public License Version 2.1 or later (the
    * "LGPL"), in which case the provisions of the LGPL are applicable instead
    * of those above. If you wish to allow use of your version of this file only
    * under the terms of the LGPL, and not to allow others to use your version of
    * this file under the terms of the EPL, indicate your decision by deleting
    * the provisions above and replace them with the notice and other provisions
    * required by the LGPL. If you do not delete the provisions above, a recipient
    * may use your version of this file under the terms of the EPL or the LGPL.
    *
    * Based on the original MiniSat specification from:
    *
    * An extensible SAT solver. Niklas Een and Niklas Sorensson. Proceedings of the
    * Sixth International Conference on Theory and Applications of Satisfiability
    * Testing, LNCS 2919, pp 502-518, 2003.
    *
    * See www.minisat.se for the original solver in C++.
    *
    *******************************************************************************/