A man on a horse lassoing.
A man is on a horse.
Horse lassoing indicates a horse.
exists x1 x2 x3.(a_topic(x1) & on(x1,x2) & n_lassoing(x2) & of(x2,x3) & n_horse(x3) & n_man(x1))
exists p1 x1.(exists x2.(on(x1,x2) & n_horse(x2)) & n_man(x1))