A man with a dog.
The man is tossing a ball to the dog.
Just because there is A man with a dog does not mean he is tossing it the ball.
exists x1 x2.(a_topic(x1) & with(x1,x2) & n_dog(x2) & n_man(x1))
exists e1 x1 x2 x3.(n_dog(x3) & n_man(x1) & Theme(e1,x2) & Actor(e1,x1) & v_toss(e1) & to(x2,x3) & n_ball(x2))