(S (S (BASENP (NNP Lopez) (NNP Obrador)) (VP (VBZ has) (VP (VP (VBN rejected) (BASENP (DT the) (NN ruling))) (CC and) (VP (VBN suggested) (S (VP (VBG forming) (BASENP (DT a) (JJ rival) (JJ parallel) (NN government)))))))) (PERIOD .))