A man in yellow grimaces.
A man is frowning at a poor joke.
A man in yellow grimaces is not necessarily frowning at a poor joke.
exists s1 x1 x2.(a_topic(x1) & in(x1,x2) & n_grimace(x2) & a_yellow(s1) & Theme(s1,x2) & n_man(x1))
exists e1 s1 x1 x2.(at(e1,x2) & n_joke(x2) & a_poor(s1) & Theme(s1,x2) & Actor(e1,x1) & v_frown(e1) & n_man(x1))