Dog chasing after a ball on the grass.
A dog is chasing a ball
A dog is chasing is rephrasing of chasing after a ball.
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 e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_chase(e1) & n_ball(x2) & n_dog(x1))