Practicing skateboarding on the court.
Skateboard practice on the concrete.
Practicing skateboarding is skateboard practice. Most courts are made of concrete.
exists e1 x1 x2 x3.(n_court(x3) & on(e1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_practice(e1) & n_skateboarding(x2) & n_thing(x1))
exists x1 x2 x3.(n_concrete(x3) & a_topic(x1) & on(x1,x3) & n_practice(x1) & (x1 = x2) & ne_nam_skateboard(x2))