Sentence trueSentence, falseSentence, andSentence, orSentence,
impliedSentence, biConditionalSentence;
@Before
public void setUp() {
parser = new PEParser();
trueSentence = (Sentence) parser.parse("true");
falseSentence = (Sentence) parser.parse("false");
andSentence = (Sentence) parser.parse("(P AND Q)");
orSentence = (Sentence) parser.parse("(P OR Q)");
impliedSentence = (Sentence) parser.parse("(P => Q)");