A man working in a machine shop.
A man is working.
Is working is a restatement of working.
exists e1 x1 x2 x3 x4.(a_topic(x1) & in(e1,x3) & n_shop(x3) & of(x3,x4) & n_machine(x4) & Actor(e1,x2) & v_work(e1) & (x1 = x2) & n_man(x1))
exists e1 x1.(Actor(e1,x1) & v_work(e1) & n_man(x1))