(S (S (BASENP (JJ Australian) (NNS rules) (NN football)) (VP (VBZ is) (VP (VBN played) (PP (IN on) (NP (BASENP (DT a) (NN field)) (NP (BASENP (NN 170) (NNS metres)) (CC by) (BASENP (NN 160) (NNS metres)))))))) (PERIOD .))