A young man with long hair practices skateboarding.
A young man is riding a skateboard.
if he is practicing skateboarding, he is riding a skateboard.
exists e1 s1 s2 x1 x2 x3 x4.(a_topic(x1) & with(x1,x2) & Actor(e1,x4) & v_skateboard(e1) & (x2 = x4) & n_practice(x2) & of(x2,x3) & n_hair(x3) & a_long(s2) & Theme(s2,x2) & n_man(x1) & a_young(s1) & Theme(s1,x1))
exists e1 s1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_skateboard(x2) & n_man(x1) & a_young(s1) & Theme(s1,x1))