A dog with a yellow toy in its mouth.
The toy is a ball.
The toy could be something other than a ball.
exists s1 x1 x2 x3.(a_topic(x1) & with(x1,x2) & in(x2,x3) & n_mouth(x3) & of(x3,x1) & n_thing(x1) & n_toy(x2) & a_yellow(s1) & Theme(s1,x2) & n_dog(x1))
exists p1 x1.(n_toy(x1) & exists x2.((x1 = x2) & n_ball(x2)))