Children are playing on the swings at a park.
Children are on recess.
Children playing on swings at a park does not imply they are at recess.
exists e1 x1 x2 x3.(n_swing(x2) & at(e1,x3) & n_park(x3) & on(e1,x2) & Actor(e1,x1) & v_play(e1) & n_child(x1))
exists p1 x1.(exists x2.(on(x1,x2) & n_recess(x2)) & n_child(x1))