A skateboarder is riding a skateboard along a metal railing in front of a concrete building.
A skateboarder is riding a skateboard
If a skateboarder is riding a skateboard, no matter where he is he is riding a skateboard.
exists e1 e2 s1 x1 x2 x3 x4 x5 x6.(along(e1,x3) & in(e2,x5) & of(x5,x6) & n_building(x6) & a_concrete(s1) & Theme(s1,x6) & n_front(x5) & Actor(e2,x4) & v_rail(e2) & (x3 = x4) & n_metal(x3) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_skateboard(x2) & n_skateboarder(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_skateboard(x2) & n_skateboarder(x1))