A child plays on playground equipment.
Someone is playing.
Child is someone.
exists e1 x1 x2 x3.(on(e1,x2) & n_equipment(x2) & of(x2,x3) & n_playground(x3) & Actor(e1,x1) & v_play(e1) & n_child(x1))
exists e1 x1.(Actor(e1,x1) & v_play(e1) & n_person(x1))