Construction workers watching a machine at it's work.
Workers building a road watch the cement truck.
The may not be constructing road and can watch anything like cement truck
exists e1 p1 x1 x2 x3 x4.(exists x5.((x1 = x5) & n_work(x5)) & at(e1,x1) & n_thing(x1) & Theme(e1,x4) & Actor(e1,x3) & v_watch(e1) & n_machine(x4) & (x1 = x3) & n_worker(x1) & of(x1,x2) & n_construction(x2))
exists e1 x1 x2 x3 x4 x5.(Theme(e1,x2) & Actor(e1,x1) & v_build(e1) & n_truck(x4) & of(x4,x5) & n_cement(x5) & (x2 = x4) & n_watch(x2) & of(x2,x3) & n_road(x3) & n_worker(x1))