A boy sitting behind the bushes.
A boy sitting playing in the dirt
A boy behind in the bushes is not assumed to be playing in the dirt.
exists e1 x1 x2 x3.(n_bush(x3) & a_topic(x1) & behind(e1,x3) & Actor(e1,x2) & v_sit(e1) & (x1 = x2) & n_boy(x1))
exists e1 x1 x2 x3.(n_dirt(x3) & a_topic(x1) & in(x1,x3) & n_playing(x1) & Actor(e1,x1) & v_sit(e1) & of(x1,x2) & n_boy(x2))