A man performing an ollie on a skateboard.
A human on a skateboard
A man is a human and he's on a skateboard.
exists e1 x1 x2 x3 x4.(a_topic(x1) & on(e1,x4) & n_skateboard(x4) & Theme(e1,x3) & Actor(e1,x2) & v_perform(e1) & n_ollie(x3) & (x1 = x2) & n_man(x1))
exists x1 x2.(a_topic(x1) & on(x1,x2) & n_skateboard(x2) & n_human(x1))