On a track, an athlete prepares to launch a javelin.
An athlete is competing in the 1500 meter swimming competition.
One can not be swimming and launch a javelin simultaneously.
exists e1 p1 x1 x2.(on(e1,x2) & n_track(x2) & Topic(e1,p1) & Actor(e1,x1) & v_prepare(e1) & exists e2 x3.(Theme(e2,x3) & Actor(e2,x1) & v_launch(e2) & n_javelin(x3)) & n_athlete(x1))
exists e1 x1 x2 x3 x4.(n_competition(x2) & of(x2,x4) & n_swimming(x4) & of(x2,x3) & n_meter(x3) & n_date(x2) & a_date_year_1500(x2) & a_date_year_1500(x2) & in(e1,x2) & Actor(e1,x1) & v_compete(e1) & n_athlete(x1))