A man on a speed motorcycle rides on a track.
The man is racing against others.
The man riding doesn't mean he is racing against others.
exists e1 x1 x2 x3 x4.(on(e1,x4) & n_track(x4) & Actor(e1,x1) & v_ride(e1) & on(x1,x2) & n_motorcycle(x2) & of(x2,x3) & n_speed(x3) & n_man(x1))
exists e1 x1 x2 x3.(n_person(x3) & n_man(x1) & against(e1,x2) & -(x2 = x3) & n_person(x2) & Actor(e1,x1) & v_race(e1))