(S (S (BASENP (NNP Li)) (VP (VBZ is) (ADJP (ADVP (RB also)) (ADJP (JJ concerned) (PP (IN about) (NP (BASENP (DT the) (NN rule)) (SBAR (WHNP (WDT which)) (S (VP (VBZ prohibits) (NP (NP (BASENP (DT the) (NN entering)) (PP (IN of) (BASENP (DT the) (JJ first-class) (NN carriage)))) (PP (IN without) (S (VP (VBG buying) (BASENP (DT a) (NN ticket))))))))))))))) (PERIOD .))