those prone to indignation need not apply 
(ROOT (S (NP (NP (DT those)) (ADJP (JJ prone) (PP (IN to) (NP (NN indignation))))) (VP (VBP need) (RB not) (VP (VB apply)))))
(ROOT (S (NP (NP (DT )) (ADJP (JJ ) (PP (IN ) (NP (NN ))))) (VP (VBP ) (RB ) (VP (VB )))))