(S (S (PP (JJ Subsequent) (PP (TO to) (BASENP (DT the) (NN operation)))) (COMMA ,) (S (BASENP (PRPD her) (NN condition)) (VP (VBD was) (VP (VBN upgraded) (PP (TO to) (QT (DQL ``) (ADJP (JJ serious) (CC but) (JJ stable)) (DQR ''))))))) (PERIOD .))