An airborne man on a surfboard.
A man trying to win the surfing competition doing tricks.
Men may do tricks on their surfboards when they are not involved in a surfing competition.
exists s1 x1 x2.(a_topic(x1) & on(x1,x2) & n_surfboard(x2) & n_man(x1) & a_airborne(s1) & Theme(s1,x1))
exists e1 p1 x1 x2 x3 x4.(n_competition(x3) & of(x3,x4) & n_surfing(x4) & a_topic(x1) & Topic(e1,p1) & Actor(e1,x2) & v_try(e1) & exists e3 e2 x5 x6.(Theme(e3,x3) & Actor(e3,x2) & v_win(e3) & Theme(e2,x6) & Actor(e2,x5) & v_do(e2) & n_trick(x6) & (x3 = x5)) & (x1 = x2) & n_man(x1))