A construction worker siting on a green tractor.
The construction is on a farm
Answer : Just because the construction is on a  farm does not mean the construction worker is sitting on a green tractor
exists e1 s1 x1 x2 x3 x4.(a_topic(x1) & on(e1,x4) & n_tractor(x4) & a_green(s1) & Theme(s1,x4) & Actor(e1,x3) & v_site(e1) & (x1 = x3) & n_worker(x1) & of(x1,x2) & n_construction(x2))
exists p1 x1.(n_construction(x1) & exists x2.(on(x1,x2) & n_farm(x2)))