Two boys play in the sand
 Two boys play on the beach.
Just because the boys are in the sand does not mean they are on a beach.
exists e1 x1 x2.(n_sand(x2) & in(e1,x2) & Actor(e1,x1) & v_play(e1) & n_boy(x1) & card_eq_2(x1))
exists e1 x1 x2.(n_beach(x2) & on(e1,x2) & Actor(e1,x1) & v_play(e1) & n_boy(x1) & card_eq_2(x1))