Two construction workers at a job site.
They are at work
Saying that they are at work clarifies what the construction workers were doing at a job site.
exists x1 x2 x3 x4.(a_topic(x1) & at(x1,x3) & n_site(x3) & of(x3,x4) & n_job(x4) & n_worker(x1) & of(x1,x2) & n_construction(x2) & card_eq_2(x1))
exists p1 x1.(n_thing(x1) & exists x2.(at(x1,x2) & n_work(x2)))