A man standing by a yellow sign.
A man is standing by a yellow caution sign.
Not all yellow signs are caution signs.
exists s1 x1 x2 x3.(a_topic(x1) & by(x1,x3) & n_sign(x3) & a_yellow(s1) & Theme(s1,x3) & n_standing(x1) & of(x1,x2) & n_man(x2))
exists e1 s1 x1 x2 x3.(by(e1,x2) & n_sign(x2) & of(x2,x3) & n_caution(x3) & a_yellow(s1) & Theme(s1,x2) & Actor(e1,x1) & v_stand(e1) & n_man(x1))