The two dogs are playing in the yard.
The two dogs are sleeping on the porch.
If the dogs are playing, then they are not sleeping
exists e1 x1 x2.(n_yard(x2) & n_dog(x1) & card_eq_2(x1) & in(e1,x2) & Actor(e1,x1) & v_play(e1))
exists e1 x1 x2.(n_porch(x2) & n_dog(x1) & card_eq_2(x1) & on(e1,x2) & Actor(e1,x1) & v_sleep(e1))