Two hikers on a dirt road.
Two hikers together.
Just because, there are two hikers on a dirt road, does not imply they are together.
exists x1 x2 x3.(a_topic(x1) & on(x1,x2) & n_road(x2) & of(x2,x3) & n_dirt(x3) & n_hiker(x1) & card_eq_2(x1))
exists x1.(a_topic(x1) & r_together(x1) & n_hiker(x1) & card_eq_2(x1))