A man fly fishing.
A man is fishing for trout.
Fly fishing is not specifically for trout.
exists x1 x2 x3.(a_topic(x1) & n_fishing(x1) & of(x1,x3) & n_fly(x3) & of(x1,x2) & n_man(x2))
exists e1 x1 x2.(for(e1,x2) & n_trout(x2) & Actor(e1,x1) & v_fish(e1) & n_man(x1))