Four children are playing on a hill of sand.
The four children are playing tag.
Just because children are playing on a hill of sand it does not mean they are playing tag.
exists e1 x1 x2 x3.(on(e1,x2) & of(x2,x3) & n_sand(x3) & n_hill(x2) & Actor(e1,x1) & v_play(e1) & n_child(x1) & card_eq_4(x1))
exists e1 x1 x2.(n_child(x1) & card_eq_4(x1) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_tag(x2))