A man hikes on a dirt path high above a city.
a man on a nature walk
A man hiking is not necessarily on a nature walk.
exists e1 x1 x2 x3 x4.(on(e1,x2) & above(x2,x4) & n_city(x4) & r_high(x2) & n_path(x2) & of(x2,x3) & n_dirt(x3) & Actor(e1,x1) & v_hike(e1) & n_man(x1))
exists x1 x2 x3.(a_topic(x1) & on(x1,x2) & Time(x2,x3) & n_walk(x3) & n_nature(x2) & n_man(x1))