They happened sleeping so of The boy .
(ROOT_0 (S_0 (ATS_3 (NP_1 (PRP_0 They)) (VP_4 (VBD_1 happened) (VP_2 (VBG_0 sleeping) (ADVP_0 (RB_1 so) (PP_0 (IN_1 of) (NP_5 (DT_0 The) (NN_2 boy))))))) (DOT_0 .)))