A large dog chases a small dog on the sand.
The dogs are taking a bath.
One dog chasing another on the sand implies that both dogs are in swift motion, possibly at a beach; while dogs taking a bath are inside a building, and are not in motion.
exists e1 s1 s2 x1 x2 x3.(n_sand(x3) & Theme(e1,x2) & Actor(e1,x1) & v_chase(e1) & on(x2,x3) & n_dog(x2) & a_small(s2) & Theme(s2,x2) & n_dog(x1) & a_large(s1) & Theme(s1,x1))
exists e1 x1 x2.(n_dog(x1) & Theme(e1,x2) & Actor(e1,x1) & v_take(e1) & n_bath(x2))