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 ))) (: )))