Dog chasing after a ball on the grass.
The dog is small
The dog that is chasing the ball, is not imply to be small.
exists x1 x2 x3 x4.(n_grass(x4) & a_topic(x1) & after(x1,x3) & on(x3,x4) & n_ball(x3) & n_chasing(x1) & (x1 = x2) & ne_nam_dog(x2))
exists s1 x1.(n_dog(x1) & Theme(s1,x1) & a_small(s1))