A man sites on a bench waiting to shoeshine.
There are no shoes.
The man cannot be waiting to shoeshine if there are no shoes.
exists e1 p1 x1 x2 x3 x4.(a_topic(x1) & on(x1,x3) & Topic(e1,p1) & Actor(e1,x4) & v_wait(e1) & exists e2.(Actor(e2,x4) & v_shoeshine(e2)) & (x3 = x4) & n_bench(x3) & n_site(x1) & of(x1,x2) & n_man(x2))
exists p1 x1.-exists x2.((x1 = x2) & n_shoe(x2))