The three children are playing on the rails.
Kids jumping on a rail.
Not all children are jumping.
exists e1 x1 x2.(n_rail(x2) & n_child(x1) & card_eq_3(x1) & on(e1,x2) & Actor(e1,x1) & v_play(e1))
exists e1 x1 x2 x3.(a_topic(x1) & on(e1,x3) & n_rail(x3) & Actor(e1,x2) & v_jump(e1) & (x1 = x2) & n_kid(x1))