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.tools; 31 32 import static org.junit.Assert.assertEquals; 33 import static org.junit.Assert.assertTrue; 34 35 import org.junit.Test; 36 import org.sat4j.core.VecInt; 37 import org.sat4j.minisat.SolverFactory; 38 import org.sat4j.specs.ContradictionException; 39 import org.sat4j.specs.ISolver; 40 import org.sat4j.specs.IVecInt; 41 import org.sat4j.specs.TimeoutException; 42 43 /** 44 * Testcase to check that the problem with unit clauses does no longer occurs. 45 * 46 * Bug report from Sebastian Henneberg 47 * 48 * 49 */ 50 public class RemiUtilsTest { 51 52 @Test 53 public void testBugUnitClauses() throws ContradictionException, 54 TimeoutException { 55 ISolver solver1 = SolverFactory.newDefault(); 56 ISolver solver2 = SolverFactory.newDefault(); 57 ISolver solver3 = SolverFactory.newDefault(); 58 59 int[][] cnf1 = new int[][] { new int[] { 1 }, new int[] { 1, -2 }, 60 new int[] { 1, -3 }, new int[] { -1, 2 } }; 61 // A & (A v -B) & (A v -C) & (-A v B) 62 // (-A v B) & (A v -B) & (A v -C) & A | using a different order 63 int[][] cnf2 = new int[][] { new int[] { -1, 2 }, new int[] { 1, -2 }, 64 new int[] { 1, -3 }, new int[] { 1 } }; 65 // (-A v B) & (A v -B) & (A v -C) & A 66 // (-A v C) & (A v -C) & (A v -B) & A | swap B and C (2 <-> 3) 67 // (A v -B) & (-A v C) & (A v -C) & A | shift the first 3 clauses to the 68 // right 69 int[][] cnf3 = new int[][] { new int[] { 1, -2 }, new int[] { -1, 3 }, 70 new int[] { 1, -3 }, new int[] { 1 } }; 71 72 for (int[] is : cnf1) { 73 solver1.addClause(new VecInt(is)); 74 } 75 for (int[] is : cnf2) { 76 solver2.addClause(new VecInt(is)); 77 } 78 for (int[] is : cnf3) { 79 solver3.addClause(new VecInt(is)); 80 } 81 82 IVecInt vecInt1 = RemiUtils.backbone(solver1); 83 assertEquals(vecInt1.size(), 2); 84 assertTrue(vecInt1.contains(1)); 85 assertTrue(vecInt1.contains(2)); 86 87 IVecInt vecInt2 = RemiUtils.backbone(solver2); 88 assertEquals(vecInt2.size(), 2); 89 assertTrue(vecInt2.contains(1)); 90 assertTrue(vecInt2.contains(2)); 91 92 IVecInt vecInt3 = RemiUtils.backbone(solver3); 93 assertEquals(vecInt3.size(), 2); 94 assertTrue(vecInt3.contains(1)); 95 assertTrue(vecInt3.contains(3)); 96 } 97 }