Two people are playing on a teeter totter.
two kids play on teeter totter
Kids are people.
exists e1 x1 x2 x3.(on(e1,x2) & n_totter(x2) & of(x2,x3) & n_teeter(x3) & Actor(e1,x1) & v_play(e1) & n_people(x1) & card_eq_2(x1))
exists e1 x1 x2 x3.(on(e1,x2) & n_totter(x2) & of(x2,x3) & n_teeter(x3) & Actor(e1,x1) & v_play(e1) & n_kid(x1) & card_eq_2(x1))