of a mixed bag , with enough negatives 
(ROOT (S (PP (IN of) (NP (DT a) (VBN mixed) (NN bag))) (, ,) (PP (IN with) (NP (JJ enough) (NNS negatives)))))
(ROOT (S (PP (IN ) (NP (DT ) (VBN ) (NN ))) (, ) (PP (IN ) (NP (JJ ) (NNS )))))