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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;
31  
32  import static org.junit.Assert.assertNotNull;
33  import static org.junit.Assert.assertNull;
34  
35  import java.util.ArrayList;
36  import java.util.Collection;
37  
38  import org.junit.Test;
39  import org.junit.runner.RunWith;
40  import org.junit.runners.Parameterized;
41  import org.junit.runners.Parameterized.Parameters;
42  import org.sat4j.core.VecInt;
43  import org.sat4j.minisat.SolverFactory;
44  import org.sat4j.specs.ContradictionException;
45  import org.sat4j.specs.IConstr;
46  import org.sat4j.specs.ISolver;
47  import org.sat4j.specs.TimeoutException;
48  
49  @RunWith(Parameterized.class)
50  public class BugSAT34 {
51  
52      ISolver system;
53      String solvername;
54  
55      public BugSAT34(ISolver system, String solvername) {
56          this.system = system;
57          this.solvername = solvername;
58      }
59  
60      @Parameters
61      public static Collection<Object[]> generateSolvers() {
62          Collection<Object[]> solvers = new ArrayList<Object[]>();
63          for (String name : SolverFactory.instance().solverNames()) {
64              if (!"DimacsOutput".equals(name)) {
65                  solvers.add(new Object[] {
66                          SolverFactory.instance().createSolverByName(name), name });
67              }
68          }
69          return solvers;
70      }
71  
72      @Test
73      public void testUnitClause() {
74          this.system.newVar(3);
75          try {
76              // x_1 v x_2 <=> x_3
77              this.system.addClause(new VecInt(new int[] { 1, 2, -3 }));
78              this.system.addClause(new VecInt(new int[] { -1, 3 }));
79              this.system.addClause(new VecInt(new int[] { -2, 3 }));
80              // not both true
81              this.system.addClause(new VecInt(new int[] { -1, -2 }));
82              // x2 is true
83              IConstr unit = this.system.addClause(new VecInt(new int[] { 2 }));
84              assertNotNull(this.solvername + " has unit clause problem", unit);
85              // x3 is true
86              IConstr cl = this.system.addAtLeast(new VecInt(new int[] { 3 }), 1);
87              assertNotNull(this.solvername + " has unit clause problem", cl);
88              int[] model = this.system.findModel();
89              assertNotNull(this.solvername + " has a model problem", model);
90              this.system.removeConstr(cl);
91              // x3 is true
92              cl = this.system.addAtLeast(new VecInt(new int[] { 3 }), 1);
93              assertNotNull(this.solvername + " has unit clause problem", cl);
94              // x1 is true
95              // so here x1, x2 and x3 is true
96              IConstr r = this.system.addClause(new VecInt(new int[] { 1 }));
97              assertNotNull(r);
98              assertNotNull(this.solvername + " has unit clause problem", r);
99              model = this.system.findModel();
100             assertNull(this.solvername + " has a model problem", model);
101         } catch (ContradictionException e) {
102         } catch (TimeoutException e) {
103         }
104         ;
105     }
106 
107 }