A dog is running towards a ball.
The dog is running.
Both subjects are running
exists e1 x1 x2.(towards(e1,x2) & n_ball(x2) & Actor(e1,x1) & v_run(e1) & n_dog(x1))
exists e1 x1.(n_dog(x1) & Actor(e1,x1) & v_run(e1))