A teen performing a bike trick at a skate park.
The skate park is empty.
A park cannot be empty if there is a teen in it.
exists e1 x1 x2 x3 x4 x5 x6.(a_topic(x1) & at(e1,x5) & n_park(x5) & of(x5,x6) & n_skate(x6) & Theme(e1,x3) & Actor(e1,x2) & v_perform(e1) & n_trick(x3) & of(x3,x4) & n_bike(x4) & (x1 = x2) & n_teen(x1))
exists s1 x1 x2.(n_park(x1) & of(x1,x2) & n_skate(x2) & Theme(s1,x1) & a_empty(s1))