A boy swings on a swing set.
A boy is with his friends at the park.
the boy on the swing set does not imply he is with his friends
exists x1 x2 x3 x4.(a_topic(x1) & on(x1,x3) & n_set(x3) & of(x3,x4) & n_swing(x4) & n_swing(x1) & of(x1,x2) & n_boy(x2))
exists p1 x1 x2 x3.(n_park(x3) & with(x1,x2) & at(x2,x3) & n_friend(x2) & of(x2,x1) & n_male(x1) & n_boy(x1))