1 /*******************************************************************************
2 * SAT4J: a SATisfiability library for Java Copyright (C) 2004, 2012 Artois University and CNRS
3 *
4 * All rights reserved. This program and the accompanying materials
5 * are made available under the terms of the Eclipse Public License v1.0
6 * which accompanies this distribution, and is available at
7 * http://www.eclipse.org/legal/epl-v10.html
8 *
9 * Alternatively, the contents of this file may be used under the terms of
10 * either the GNU Lesser General Public License Version 2.1 or later (the
11 * "LGPL"), in which case the provisions of the LGPL are applicable instead
12 * of those above. If you wish to allow use of your version of this file only
13 * under the terms of the LGPL, and not to allow others to use your version of
14 * this file under the terms of the EPL, indicate your decision by deleting
15 * the provisions above and replace them with the notice and other provisions
16 * required by the LGPL. If you do not delete the provisions above, a recipient
17 * may use your version of this file under the terms of the EPL or the LGPL.
18 *
19 * Based on the original MiniSat specification from:
20 *
21 * An extensible SAT solver. Niklas Een and Niklas Sorensson. Proceedings of the
22 * Sixth International Conference on Theory and Applications of Satisfiability
23 * Testing, LNCS 2919, pp 502-518, 2003.
24 *
25 * See www.minisat.se for the original solver in C++.
26 *
27 * Contributors:
28 * CRIL - initial API and implementation
29 *******************************************************************************/
30 package org.sat4j.minisat.learning;
31
32 import org.sat4j.minisat.constraints.cnf.WLClause;
33 import org.sat4j.minisat.core.Constr;
34 import org.sat4j.minisat.core.DataStructureFactory;
35
36 /**
37 * The solver only records among all the constraints only the clauses.
38 *
39 * @author daniel
40 *
41 * @param <L>
42 * a data structure for the literals.
43 * @param <D>
44 * a data structure for the clauses.
45 */
46 public final class ClauseOnlyLearning<D extends DataStructureFactory> extends
47 LimitedLearning<D> {
48
49 /**
50 *
51 */
52 private static final long serialVersionUID = 1L;
53
54 @Override
55 protected boolean learningCondition(Constr constr) {
56 return constr instanceof WLClause;
57 }
58
59 @Override
60 public String toString() {
61 return "Limit learning to clauses using watched literals only";
62 }
63 }