A man fly fishes in the ocean.
The man is fishing.
A man fly fishes is inferred as  The man is fishing.
exists x1 x2 x3 x4.(n_ocean(x4) & a_topic(x1) & in(x1,x4) & n_fish(x1) & of(x1,x3) & n_fly(x3) & of(x1,x2) & n_man(x2))
exists p1 x1.(n_man(x1) & exists x2.((x1 = x2) & n_fishing(x2)))