A woman combing another woman's hair.
A woman is combing a woman's hair.
A woman is not combing her hair.  A woman is combing someone else hair.
exists e1 x1 x2 x3 x4.(a_topic(x1) & Theme(e1,x4) & Actor(e1,x2) & v_comb(e1) & n_hair(x4) & of(x4,x3) & n_woman(x3) & -(x3 = x1) & n_woman(x1) & n_woman(x1) & (x1 = x2))
exists e1 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_comb(e1) & n_hair(x3) & of(x3,x2) & n_woman(x2) & n_woman(x1))