Four girls ride sit on a riding tractor on a farm.
Four friend riding a tractor in the winter.
Four girls sitting on a tractor need not necessarily be friends and that it need not  be WINTER.
exists e1 x1 x2 x3 x4 x5.(on(e1,x5) & n_farm(x5) & on(e1,x3) & n_tractor(x3) & of(x3,x4) & n_riding(x4) & Actor(e1,x1) & v_sit(e1) & n_ride(x1) & of(x1,x2) & n_girl(x2) & card_eq_4(x1))
exists e1 x1 x2 x3 x4.(n_winter(x4) & a_topic(x1) & in(e1,x4) & Theme(e1,x3) & Actor(e1,x2) & v_ride(e1) & n_tractor(x3) & (x1 = x2) & n_friend(x1) & card_eq_4(x1))