A young girl is riding a white horse.
The horse belongs to the girl
A young girl riding a horse is not necessarily a horse that belongs to the girl.
exists e1 s1 s2 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_horse(x2) & a_white(s2) & Theme(s2,x2) & n_girl(x1) & a_young(s1) & Theme(s1,x1))
exists e1 x1 x2.(n_girl(x2) & n_horse(x1) & to(e1,x2) & Actor(e1,x1) & v_belong(e1))