A large duck in flight over a rocky stream.
A duck is flying south for the winter.
Can not tell if it is winter or that the duck is flying south.
exists s1 s2 x1 x2 x3.(a_topic(x1) & in(x1,x2) & over(x2,x3) & n_stream(x3) & a_rocky(s2) & Theme(s2,x3) & n_flight(x2) & n_duck(x1) & a_large(s1) & Theme(s1,x1))
exists e1 s1 x1 x2.(n_winter(x2) & for(e1,x2) & a_south(s1) & Manner(e1,s1) & Actor(e1,x1) & v_fly(e1) & n_duck(x1))