@Test
public void t03_simpleGrouping() throws Exception {

    String e1 = "tagA and (not tagB or tagC)";
    assertEquals("and(tagA, or(tagC, not tagB))", parser.parse(e1));
    String e2 = "tagA and (not tagB and tagC)";
    assertEquals("and(tagA, and(tagC, not tagB))", parser.parse(e2));
    String e3 = "(not tagB or tagC) and tagA";
    assertEquals("and(tagA, or(tagC, not tagB))", parser.parse(e3));
}