A black dog is retrieving a ball in water.
A dog sleeps in his dog bed.
If the dog sleeps in his bed, he cannot be retrieving a ball at the same time.
exists e1 s1 x1 x2 x3.(in(e1,x3) & n_water(x3) & Theme(e1,x2) & Actor(e1,x1) & v_retrieve(e1) & n_ball(x2) & n_dog(x1) & a_black(s1) & Theme(s1,x1))
exists e1 x1 x2.(in(e1,x2) & n_bed(x2) & of(x2,x1) & n_dog(x1) & n_dog(x1) & of(x2,x1) & n_male(x1) & Actor(e1,x1) & v_sleep(e1))