if the laborious pacing and endless exposition had been tightened 
(ROOT (SBAR (IN if) (S (NP (DT the) (JJ laborious) (NML (NML (NN pacing)) (CC and) (NML (JJ endless) (NN exposition)))) (VP (VBD had) (VP (VBN been) (VP (VBN tightened)))))))
(ROOT (SBAR (IN ) (S (NP (DT ) (JJ ) (NML (NML (NN )) (CC ) (NML (JJ ) (NN )))) (VP (VBD ) (VP (VBN ) (VP (VBN )))))))