There are people on the beach in the sand.
the people are playing
Not all people on the beach are playing.
exists p1 x1 x2 x4.(n_sand(x2) & n_beach(x4) & in(p1,x2) & exists x3.((x1 = x3) & on(x3,x4) & n_people(x3)))
exists e1 x1.(n_people(x1) & Actor(e1,x1) & v_play(e1))