under muscle with muscle thick , <apostrophe><apostrophe>
(ROOT_0 (S_0 (ATS_2 (PP_2 (IN_0 under) (NP_3 (NP_5 (NN_3 muscle)) (PP_2 (IN_0 with) (NP_6 (NN_3 muscle) (JJ_0 thick))))) (COMMA_0 ,)) (APOSTROPHE_0 <apostrophe><apostrophe>)))