Construction workers working on a building.
Some workers are working at a site.
Construction workers are a kind of workers who work on building site.
exists e1 x1 x2 x3.(on(e1,x3) & n_building(x3) & Actor(e1,x1) & v_work(e1) & n_worker(x1) & of(x1,x2) & n_construction(x2))
exists e1 x1 x2.(at(e1,x2) & n_site(x2) & Actor(e1,x1) & v_work(e1) & n_worker(x1))