The boy on the bike is wearing safety glasses and a helmet.
A boy on his skateboard.
There can either be a bike or a skateboard.
exists e1 x1 x2 x3 x4 x5 x6.(n_bike(x2) & n_boy(x1) & Theme(e1,x3) & Actor(e1,x1) & v_wear(e1) & subset_of(x6,x3) & n_helmet(x6) & subset_of(x4,x3) & n_glass(x4) & of(x4,x5) & n_safety(x5) & on(x1,x2))
exists x1 x2.(a_topic(x1) & on(x1,x2) & n_skateboard(x2) & of(x2,x1) & n_male(x1) & n_boy(x1))