A person walking up the stairs.
The person is taking the elevator.
The person is either taking the stairs or the elevator.
exists e1 s1 x1 x2 x3.(n_stair(x3) & a_topic(x1) & a_up(s1) & Manner(e1,s1) & Theme(e1,x3) & Actor(e1,x2) & v_walk(e1) & (x1 = x2) & n_person(x1))
exists e1 x1 x2.(n_elevator(x2) & n_person(x1) & Theme(e1,x2) & Actor(e1,x1) & v_take(e1))