is a subzero version of monsters , inc. , 
(ROOT (VP (VBZ is) (NP (NP (DT a) (NN subzero) (NN version)) (PP (IN of) (NP (NP (NNS monsters)) (, ,) (NP (NNP inc.)) (, ,))))))
(ROOT (VP (VBZ ) (NP (NP (DT ) (NN ) (NN )) (PP (IN ) (NP (NP (NNS )) (, ) (NP (NNP )) (, ))))))