A small dog carries a yellow ball through the grass.
A dog doesn't have a ball.
A dog should have a ball or not a ball at a time.
exists e1 s1 s2 x1 x2 x3.(n_grass(x3) & through(e1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_carry(e1) & n_ball(x2) & a_yellow(s2) & Theme(s2,x2) & n_dog(x1) & a_small(s1) & Theme(s1,x1))
exists x1.(-exists e1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_have(e1) & n_ball(x2)) & n_dog(x1))