The boy is jumping a skateboard down the steps, surrounded by graffiti covered walls.
The boy is good at tricks.
Just because the boy is jumping a skateboard doesn't mean he is good at tricks.
exists e2 e3 e1 x1 x2 x3 x4 x5 x6.(n_step(x3) & n_boy(x1) & down(e1,x3) & Actor(e2,x5) & n_wall(x5) & Theme(e3,x5) & v_cover(e3) & of(x5,x6) & n_graffitus(x6) & Theme(e2,x4) & v_surround(e2) & (x3 = x4) & Theme(e1,x2) & Actor(e1,x1) & v_jump(e1) & n_skateboard(x2))
exists s1 x1 x2.(n_boy(x1) & at(s1,x2) & n_trick(x2) & Theme(s1,x1) & a_good(s1))