A man helps a boy ride a bike.
A boy is riding a bike.
To ride a bike means to be riding.
exists x1.(all x2.(n_bike(x2) -> exists e1 x3 x4.(Theme(e1,x3) & Actor(e1,x1) & v_help(e1) & for(x3,x2) & n_ride(x3) & of(x3,x4) & n_boy(x4))) & n_man(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_bike(x2) & n_boy(x1))