A red biplane streaks across the sky leaving a white trail behind it.
A plane in the sky.
Both sentence are talking about plane and sky
exists e1 s1 s2 x1 x2 x3 x4.(n_thing(x3) & n_sky(x3) & behind(e1,x3) & Theme(e1,x4) & Actor(e1,x1) & v_leave(e1) & n_trail(x4) & a_white(s2) & Theme(s2,x4) & across(x1,x3) & n_streak(x1) & of(x1,x2) & n_biplane(x2) & a_red(s1) & Theme(s1,x1))
exists x1 x2.(n_sky(x2) & a_topic(x1) & in(x1,x2) & n_plane(x1))