A man walking in brush with a big orange backpack.
A man on a hike.
Just because a man is walking in brush it does not mean he is on a hike.
exists s1 x1 x2 x3 x4 x5.(a_topic(x1) & in(x1,x3) & with(x3,x4) & n_backpack(x4) & of(x4,x5) & n_orange(x5) & a_big(s1) & Theme(s1,x4) & n_brush(x3) & n_walking(x1) & of(x1,x2) & n_man(x2))
exists x1 x2.(a_topic(x1) & on(x1,x2) & n_hike(x2) & n_man(x1))