(S (S (BASENP (NNS Technicians)) (VP (VBP are) (VP (ADVP (RB now)) (VP (VBG working) (S (VP (TO to) (VP (VB repair) (NP (BASENP (JJ technical) (NNS glitches)) (VP (VP (VBN discovered) (BASENP (NN yesterday))) (PP (IN on) (BASENP (DT a) (JJ main) (NN engine) (NN control) (NN computer)))))))))))) (PERIOD .))