A man in a welders helmet sitting on a metal beam.
The man is a construction worker.
Not all the men with a metal beam are worker
exists e1 x1 x2 x3 x4 x5 x6.(a_topic(x1) & in(x1,x2) & on(e1,x5) & n_beam(x5) & of(x5,x6) & n_metal(x6) & Actor(e1,x4) & v_sit(e1) & (x2 = x4) & n_helmet(x2) & of(x2,x3) & n_welder(x3) & n_man(x1))
exists p1 x1.(n_man(x1) & exists x2 x3.((x1 = x2) & n_worker(x2) & of(x2,x3) & n_construction(x3)))