A toddler is sitting in a swing at a park.
a swing is being used
If a toddler is sitting in a swing, then a swing is being used.
exists e1 x1 x2 x3.(at(e1,x3) & n_park(x3) & in(e1,x2) & n_swing(x2) & Actor(e1,x1) & v_sit(e1) & n_toddler(x1))
exists e1 x1.(Theme(e1,x1) & v_use(e1) & n_swing(x1))