(S (BASENP (PRP He)) (VP (ADVP (RB later)) (VP (VP (VP (VBD characterized) (S (BASENP (NNP Stanislaw) (NNP Ulam)) (VP (VBD was) (NP (BASENP (DT the) (QT (DQL ``) (NN father) (DQR ''))) (PP (IN of) (BASENP (DT the) (NN hydrogen) (NN bomb))))))) (CONJP (COMMA ,) (CC and)) (VP (BASENP (NNP Edward) (NNP Teller)) (PP (IN as) (NP (PRPD its) (QT (DQL ``) (QTC (BASENP (NN mother)) (COMMA ,)) (DQR '')))))) (CC and) (VP (BASENP (PRP himself)) (PP (IN as) (NP (PRPD its) (QT (DQL ``) (QTC (BASENP (NN midwife)) (PERIOD .)) (DQR ''))))))))