Dogs play with stick
Dogs are playing with a ball.
Stick is not a ball
exists e1 x1 x2.(with(e1,x2) & n_stick(x2) & Actor(e1,x1) & v_play(e1) & n_dog(x1))
exists e1 x1 x2.(with(e1,x2) & n_ball(x2) & Actor(e1,x1) & v_play(e1) & n_dog(x1))