A dog with a blue ball.
A black dog with a blue ball.
Dogs can be many colors besides black.
exists s1 x1 x2.(a_topic(x1) & with(x1,x2) & n_ball(x2) & a_blue(s1) & Theme(s1,x2) & n_dog(x1))
exists s1 s2 x1 x2.(a_topic(x1) & with(x1,x2) & n_ball(x2) & a_blue(s2) & Theme(s2,x2) & n_dog(x1) & a_black(s1) & Theme(s1,x1))