Kids are playing in the sand.
Kids are playing.
Kids playing in the sand is a form of playing.
exists e1 x1 x2.(n_sand(x2) & in(e1,x2) & Actor(e1,x1) & v_play(e1) & n_kid(x1))
exists e1 x1.(Actor(e1,x1) & v_play(e1) & n_kid(x1))