(S (S (BASENP (NNP Spain)) (VP (VP (VBZ uses) (NP (BASENP (NN uncertainty)) (PP (IN over) (BASENP (NNP EU) (NN membership))))) (S (VP (TO to) (VP (VP (VB deter) (BASENP (NNP Catalonia))) (PP (IN from) (S (VP (ADVP (RB even)) (VP (VBG holding) (NP (BASENP (DT a) (NN referendum)) (PP (IN on) (BASENP (NN independence))))))))))))) (PERIOD .))