A boy is skateboarding in a skateboard park.
The boy is 15
The boy could be any age and not just 15.
exists e1 x1 x2 x3.(in(e1,x2) & n_park(x2) & of(x2,x3) & n_skateboard(x3) & Actor(e1,x1) & v_skateboard(e1) & n_boy(x1))
exists p1 x1.(n_boy(x1) & exists x2.((x1 = x2) & n_date(x2) & a_date_day_15(x2) & a_date_day_15(x2)))