A black dog walks through the water.
The dog is retrieving something.
Dog walks through the water not necessarily retrieving something.
exists e1 s1 x1 x2.(n_water(x2) & through(e1,x2) & Actor(e1,x1) & v_walk(e1) & n_dog(x1) & a_black(s1) & Theme(s1,x1))
exists e1 x1 x2.(n_dog(x1) & Theme(e1,x2) & Actor(e1,x1) & v_retrieve(e1) & n_thing(x2))