Young skateboarder doing a trick in the park.
a person does tricks on a skateboard
If a person is a skateboarder, it follows that they are on a skateboard.
exists e1 s1 x1 x2 x3 x4.(n_park(x4) & a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_do(e1) & in(x3,x4) & n_trick(x3) & (x1 = x2) & n_skateboarder(x1) & a_young(s1) & Theme(s1,x1))
exists e1 x1 x2 x3.(on(e1,x3) & n_skateboard(x3) & Theme(e1,x2) & Actor(e1,x1) & v_do(e1) & n_trick(x2) & n_person(x1))