A man at work, butchering a cow.
A butcher works on a cow.
If the man is at work butchering a cow, then he is a butcher.
exists e1 x1 x2 x3 x4.(a_topic(x1) & Theme(e1,x4) & Actor(e1,x3) & v_butcher(e1) & n_cow(x4) & (x1 = x3) & at(x1,x2) & n_work(x2) & n_man(x1))
exists e1 x1 x2.(on(e1,x2) & n_cow(x2) & Actor(e1,x1) & v_work(e1) & n_butcher(x1))