A woman taking a photo by a creek.
A woman not taking a photo
A woman not taking a photo cannot be taking a photo
exists e1 x1 x2 x3 x4.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_take(e1) & by(x3,x4) & n_creek(x4) & n_photo(x3) & (x1 = x2) & n_woman(x1))
exists x1 x2.(a_topic(x1) & -exists e1 x3.(Theme(e1,x3) & Actor(e1,x2) & v_take(e1) & n_photo(x3)) & (x1 = x2) & n_woman(x1))