Children are playing on a playground.
The children are outside.
Play ground must be at outside.
exists e1 x1 x2.(on(e1,x2) & n_playground(x2) & Actor(e1,x1) & v_play(e1) & n_child(x1))
exists s1 x1.(n_child(x1) & Theme(s1,x1) & a_outside(s1))