Someone riding sideways on a motorcycle.
A person on a motorcycle is ridding sideways
The person refers to someone who is riding sideways on a motorcycle.
exists e1 x1 x2.(on(e1,x2) & n_motorcycle(x2) & Actor(e1,x1) & v_sideway(e1) & n_riding(x1))
exists e1 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_rid(e1) & n_sideway(x3) & on(x1,x2) & n_motorcycle(x2) & n_person(x1))