1 /*
2 * SAT4J: a SATisfiability library for Java Copyright (C) 2004-2006 Daniel Le Berre
3 *
4 * Based on the original minisat specification from:
5 *
6 * An extensible SAT solver. Niklas E?n and Niklas S?rensson. Proceedings of the
7 * Sixth International Conference on Theory and Applications of Satisfiability
8 * Testing, LNCS 2919, pp 502-518, 2003.
9 *
10 * This library is free software; you can redistribute it and/or modify it under
11 * the terms of the GNU Lesser General Public License as published by the Free
12 * Software Foundation; either version 2.1 of the License, or (at your option)
13 * any later version.
14 *
15 * This library is distributed in the hope that it will be useful, but WITHOUT
16 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
17 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
18 * details.
19 *
20 * You should have received a copy of the GNU Lesser General Public License
21 * along with this library; if not, write to the Free Software Foundation, Inc.,
22 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 *
24 */
25 package org.sat4j.specs;
26
27 /**
28 * The most general abstraction for handling a constraint.
29 *
30 * @author leberre
31 *
32 */
33 public interface IConstr {
34
35 /**
36 * @return true iff the clause was learnt during the search
37 */
38 boolean learnt();
39
40 /**
41 * @return the number of literals in the constraint.
42 */
43 int size();
44
45 /**
46 * returns the ith literal in the constraint
47 *
48 * @param i
49 * the index of the literal
50 * @return a literal
51 */
52 int get(int i);
53
54 }