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