A man is smoking at sunset.
A man smoking a cigarette.
There are other things one may smoke beyond a cigarette.
exists e1 x1 x2.(at(e1,x2) & n_sunset(x2) & Actor(e1,x1) & v_smoke(e1) & n_man(x1))
exists e1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_smoke(e1) & n_cigarette(x3) & (x1 = x2) & n_man(x1))