those prone to indignation need not apply ; those susceptible to blue hilarity , step right up 
(ROOT (S (S (NP (NP (DT those)) (ADJP (JJ prone) (PP (IN to) (NP (NN indignation))))) (VP (VBP need) (RB not) (VP (VB apply)))) (, ;) (S (NP (NP (DT those)) (ADJP (JJ susceptible) (PP (IN to) (NP (JJ blue) (NN hilarity))))) (, ,) (VP (NN step) (ADVP (RB right) (RB up))))))
(ROOT (S (S (NP (NP (DT )) (ADJP (JJ ) (PP (IN ) (NP (NN ))))) (VP (VBP ) (RB ) (VP (VB )))) (, ) (S (NP (NP (DT )) (ADJP (JJ ) (PP (IN ) (NP (JJ ) (NN ))))) (, ) (VP (NN ) (ADVP (RB ) (RB ))))))