Three workers in fluorescent orange clothing cleaning the subway tracks.
The workers are busy cleaning the tracks.
The workers must be busy if they are cleaning the tracks.
exists e1 s1 x1 x2 x3 x4 x5 x6.(n_track(x5) & of(x5,x6) & n_subway(x6) & a_topic(x1) & in(x1,x2) & Theme(e1,x5) & Actor(e1,x4) & v_clean(e1) & (x2 = x4) & n_clothing(x2) & of(x2,x3) & n_orange(x3) & a_fluorescent(s1) & Theme(s1,x2) & n_worker(x1) & card_eq_3(x1))
exists e1 p1 x1 x2.(n_track(x2) & n_worker(x1) & exists e2.(Theme(e2,x2) & Actor(e2,x1) & v_clean(e2)) & Topic(e1,p1) & Actor(e1,x1) & v_busy(e1))