The hawk swoops down upon its prey.
A hawk is sitting on a nest.
prey and nest are two different things
exists e1 s1 x1 x2.(n_prey(x2) & of(x2,x1) & n_thing(x1) & n_hawk(x1) & a_down(s1) & Manner(e1,s1) & upon(e1,x2) & Actor(e1,x1) & v_swoop(e1))
exists e1 x1 x2.(on(e1,x2) & n_nest(x2) & Actor(e1,x1) & v_sit(e1) & n_hawk(x1))