View Javadoc

1   /*******************************************************************************
2    * SAT4J: a SATisfiability library for Java Copyright (C) 2004-2008 Daniel Le Berre
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   *******************************************************************************/
28  package org.sat4j.minisat.constraints.cnf;
29  
30  import org.sat4j.minisat.core.ILits;
31  import org.sat4j.minisat.core.UnitPropagationListener;
32  import org.sat4j.specs.IVecInt;
33  
34  public final class OriginalWLClause extends WLClause {
35  
36  	public OriginalWLClause(IVecInt ps, ILits voc) {
37  		super(ps, voc);
38  	}
39  
40  	/**
41       * 
42       */
43  	private static final long serialVersionUID = 1L;
44  
45  	/*
46  	 * (non-Javadoc)
47  	 * 
48  	 * @see org.sat4j.minisat.constraints.cnf.WLClause#register()
49  	 */
50  	public void register() {
51  		assert lits.length > 1;
52  		voc.watch(lits[0] ^ 1, this);
53  		voc.watch(lits[1] ^ 1, this);
54  	}
55  
56  	public boolean learnt() {
57  		return false;
58  	}
59  
60  	public void setLearnt() {
61  		// do nothing
62  	}
63  
64  	/**
65  	 * Creates a brand new clause, presumably from external data.
66  	 * 
67  	 * @param s
68  	 *            the object responsible for unit propagation
69  	 * @param voc
70  	 *            the vocabulary
71  	 * @param literals
72  	 *            the literals to store in the clause
73  	 * @return the created clause or null if the clause should be ignored
74  	 *         (tautology for example)
75  	 */
76  	public static OriginalWLClause brandNewClause(UnitPropagationListener s,
77  			ILits voc, IVecInt literals) {
78  		OriginalWLClause c = new OriginalWLClause(literals, voc);
79  		c.register();
80  		return c;
81  	}
82  
83  	/**
84  	 * @since 2.1
85  	 */
86  	public void forwardActivity(double claInc) {
87  		activity += claInc;
88  	}
89  
90  	/**
91  	 * @param claInc
92  	 */
93  	public void incActivity(double claInc) {
94  
95  	}
96  
97  }