There are two young people with backpacks on and then are standing next to a hiking trail.
The couple is about to go on a hike
The two young people are not necessarily a couple.  The couple is not necessarily about to go on a hike.
exists e1 p1 p2 s1 x1 x2.(a_then(s1) & Manner(e1,s1) & exists s3 x7 x8.(to(s3,x7) & n_trail(x7) & of(x7,x8) & n_hiking(x8) & Theme(s3,x2) & a_next(s3)) & Topic(e1,p2) & Actor(e1,x2) & v_stand(e1) & exists s2 x3 x4 x5 x6.((x1 = x3) & on(x3,x5) & n_trail(x5) & of(x5,x6) & n_hiking(x6) & with(x3,x4) & n_backpack(x4) & n_people(x3) & a_young(s2) & Theme(s2,x3) & card_eq_2(x3)))
exists p1 s1 x1.(n_couple(x1) & Topic(s1,p1) & Actor(s1,x1) & a_about(s1) & exists e1 x2.(on(e1,x2) & n_hike(x2) & Actor(e1,x1) & v_go(e1)))