@Test
  public void testAimaExample() {
    Sentence aimaEg = (Sentence) parser.parse("( B11 <=> (P12 OR P21))");
    CNFTransformer transformer = new CNFTransformer();
    Sentence transformed = transformer.transform(aimaEg);
    Set<Sentence> clauses = gatherer.getClausesFrom(transformed);
    Sentence clause1 = (Sentence) parser.parse("( B11 OR  ( NOT P12 )  )");
    Sentence clause2 = (Sentence) parser.parse("( B11 OR  ( NOT P21 )  )");
    Sentence clause3 = (Sentence) parser
        .parse("(  ( NOT B11 )  OR  ( P12 OR P21 ) )");