A bicyclist riding on a city street.
A person driving a car down the street.
Person driving a car can not be a bicyclist at the same time.
exists x1 x2 x3 x4.(a_topic(x1) & on(x1,x3) & n_street(x3) & of(x3,x4) & n_city(x4) & n_riding(x1) & of(x1,x2) & n_bicyclist(x2))
exists e1 x1 x2 x3 x4.(n_street(x4) & a_topic(x1) & down(e1,x4) & Theme(e1,x3) & Actor(e1,x2) & v_drive(e1) & n_car(x3) & (x1 = x2) & n_person(x1))