A man skateboarding on the side of steps
A man on a skateboard.
Skateboarding implies being on a skateboard
exists e1 x1 x2 x3 x4.(n_side(x3) & a_topic(x1) & on(e1,x3) & of(x3,x4) & n_step(x4) & Actor(e1,x2) & v_skateboard(e1) & (x1 = x2) & n_man(x1))
exists x1 x2.(a_topic(x1) & on(x1,x2) & n_skateboard(x2) & n_man(x1))