A boy pushes another boy on a swing set.
boys playing
Pushing is a form of playing.
exists e1 x1 x2 x3 x4.(Theme(e1,x2) & Actor(e1,x1) & v_push(e1) & on(x2,x3) & n_set(x3) & of(x3,x4) & n_swing(x4) & n_boy(x2) & -(x2 = x1) & n_boy(x1) & n_boy(x1))
exists e1 x1 x2.(a_topic(x1) & Actor(e1,x2) & v_play(e1) & (x1 = x2) & n_boy(x1))