A safety worker is checking the railway.
A man is sitting on a couch.
A person cannot both be checking the railway and sitting on a couch.
exists e1 x1 x2 x3.(n_railway(x3) & Theme(e1,x3) & Actor(e1,x1) & v_check(e1) & n_worker(x1) & of(x1,x2) & n_safety(x2))
exists e1 x1 x2.(on(e1,x2) & n_couch(x2) & Actor(e1,x1) & v_sit(e1) & n_man(x1))