The black dog is in the water with a white object in its mouth.
A dog fetches the ball in the lake.
The dog may not have fetched the object. The white object does could be a plush toy instead of a ball.
exists p1 s1 x1 x2 x4.(n_mouth(x4) & of(x4,x2) & n_thing(x2) & n_water(x2) & n_dog(x1) & a_black(s1) & Theme(s1,x1) & exists s2 x3.(in(x1,x2) & with(x2,x3) & in(x3,x4) & n_object(x3) & a_white(s2) & Theme(s2,x3)))
exists e1 x1 x2 x3.(n_lake(x3) & n_ball(x2) & in(e1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_fetch(e1) & n_dog(x1))