A boy swings in the air.
A boy swings from jail bars
If the boy swings from jail bars, he is not in the air.
exists x1 x2 x3.(n_air(x3) & a_topic(x1) & in(x1,x3) & n_swing(x1) & of(x1,x2) & n_boy(x2))
exists x1 x2 x3 x4.(a_topic(x1) & from(x1,x3) & n_bar(x3) & of(x3,x4) & n_jail(x4) & n_swing(x1) & of(x1,x2) & n_boy(x2))