A man waits at a crosswalk holding a motorbike helmet.
A motorcyclist waits to cross the street.
All people holding a motorbike helmet are not necessarily a motorcyclist.
exists e1 e2 x1 x2 x3 x4 x5.(at(e1,x2) & Theme(e2,x4) & Actor(e2,x3) & v_hold(e2) & n_helmet(x4) & of(x4,x5) & n_motorbike(x5) & (x2 = x3) & n_crosswalk(x2) & Actor(e1,x1) & v_wait(e1) & n_man(x1))
exists e1 p1 x1 x2.(n_street(x2) & Topic(e1,p1) & Actor(e1,x1) & v_wait(e1) & exists e2.(Theme(e2,x2) & Actor(e2,x1) & v_cross(e2)) & n_motorcyclist(x1))