The helmeted boy is doing a stunt on a skateboard.
A boy is participating in a skateboarding competition at the park.
Doing a stunt does not mean that he participating in a competition.
exists e1 s1 x1 x2 x3.(n_boy(x1) & a_helmeted(s1) & Theme(s1,x1) & Theme(e1,x2) & Actor(e1,x1) & v_do(e1) & on(x2,x3) & n_skateboard(x3) & n_stunt(x2))
exists e2 e1 x1 x2 x3.(n_park(x3) & at(e1,x3) & in(e1,x2) & n_competition(x2) & Actor(e2,x2) & v_skateboard(e2) & Actor(e1,x1) & v_participate(e1) & n_boy(x1))