A group of construction workers going down a flight of stairs.
Workers took an elevator.
Workers cannot take the elevator if they took the stairs.
exists e1 s1 x1 x2 x3 x4 x5 x6.(a_topic(x1) & a_down(s1) & Manner(e1,s1) & Theme(e1,x5) & Actor(e1,x4) & v_go(e1) & of(x5,x6) & n_stair(x6) & n_flight(x5) & (x1 = x4) & of(x1,x2) & n_worker(x2) & of(x2,x3) & n_construction(x3) & n_group(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_take(e1) & n_elevator(x2) & n_worker(x1))