A man on a horse lassoing.
A girl is riding her horse.
A man lassoing is not the same as a girl riding her horse.
exists x1 x2 x3.(a_topic(x1) & on(x1,x2) & n_lassoing(x2) & of(x2,x3) & n_horse(x3) & n_man(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_horse(x2) & of(x2,x1) & n_female(x1) & n_girl(x1))