Families are playing at the park on tire swings.
There are people on the tire swings.
People playing on tire swings are definitely on the tire swings.
exists e1 x1 x2 x3 x4.(n_park(x2) & at(e1,x2) & on(x2,x3) & n_swing(x3) & of(x3,x4) & n_tire(x4) & Actor(e1,x1) & v_play(e1) & n_family(x1))
exists p1 x1 x3 x4.(n_swing(x3) & of(x3,x4) & n_tire(x4) & exists x2.((x1 = x2) & on(x2,x3) & n_people(x2)))