A teenager boy does a trick with his skateboard against a wall.
A teen boy on a bike.
The boy is either on a skateboard or bike. Can not be both.
exists e1 x1 x2 x3 x4 x5.(with(e1,x4) & against(x4,x5) & n_wall(x5) & n_skateboard(x4) & of(x4,x1) & n_male(x1) & Theme(e1,x3) & Actor(e1,x1) & v_do(e1) & n_trick(x3) & n_boy(x1) & of(x1,x2) & n_teenager(x2))
exists s1 x1 x2.(a_topic(x1) & on(x1,x2) & n_bike(x2) & n_boy(x1) & a_teen(s1) & Theme(s1,x1))