c2 = new Clause();
c1.addPositiveLiteral(new Predicate("Pred1", new ArrayList<Term>()));
c1.addPositiveLiteral(new Predicate("Pred2", new ArrayList<Term>()));
c1.addNegativeLiteral(new Predicate("Pred3", new ArrayList<Term>()));
c1.addNegativeLiteral(new Predicate("Pred4", new ArrayList<Term>()));
c2.addPositiveLiteral(new Predicate("Pred2", new ArrayList<Term>()));
c2.addNegativeLiteral(new Predicate("Pred4", new ArrayList<Term>()));
Assert.assertNotNull(c1.binaryResolvents(c2));
Assert.assertEquals(0, c1.binaryResolvents(c2).size());
Assert.assertNotNull(c2.binaryResolvents(c1));
Assert.assertEquals(0, c2.binaryResolvents(c1).size());