A city street is illuminated by lamps at night.
The street is kept bright by lamps at night for safety.
A city street is illuminated by lamps at night doesn't imply it is done for safety
exists e1 x1 x2 x3 x4.(at(e1,x4) & n_night(x4) & Actor(e1,x3) & n_lamp(x3) & Theme(e1,x1) & v_illuminate(e1) & n_street(x1) & of(x1,x2) & n_city(x2))
exists e1 p1 x1 x2 x3 x4.(n_street(x1) & at(e1,x3) & for(x3,x4) & n_safety(x4) & n_night(x3) & Actor(e1,x2) & n_lamp(x2) & exists s1.(Theme(s1,x1) & a_bright(s1)) & Recipient(e1,p1) & Topic(e1,x1) & v_keep(e1))