(S (S (S (BASENP (DT The) (NN system)) (VP (VBZ has) (VP (VBN had) (NP (JJ several) (BASENP (VBN set) (NNS backs)))))) (SBAR (IN since) (S (BASENP (NN construction)) (VP (VP (VBD began) (PRN (COMMA ,) (PP (IN with) (S (NP (BASENP (DT the) (NN network)) (VP (ADVP (RB now)) (VP (VBN set) (S (VP (TO to) (VP (VP (VB open) (PP (IN in) (BASENP (NNS stages)))) (PP (IN with) (NP (NP (BASENP (DT a) (NN number)) (PP (IN of) (BASENP (NN tram) (NNS lines)))) (PRN (LRB -LRB-) (NP (CC but) (NP (RB not) (NP (BASENP (DT the) (NNS trams)) (SBAR (S (VP (TO to) (VP (VB operate) (BASENP (PRP them))))))))) (RRB -RRB-)))))))))) (VP (VBG being) (VP (VBN canceled))))) (COMMA ,))) (S (VP (VBG leading) (PP (TO to) (NP (BASENP (DT a) (JJ large) (NN surplus)) (PP (IN of) (NP (BASENP (NNS vehicles)) (SBAR (WHNP (WDT that)) (S (VP (MD could) (VP (VB be) (VP (VP (VBN hired) (PRT (RP out))) (PP (IN in) (BASENP (DT the) (JJ short) (NN term)))))))))))))))))) (PERIOD .))