A man works on constructing the stairway in a building.
A man is falling down stairs.
A man constructing a stairway will not be falling down the stairs.
exists e2 e1 x1 x2 x3 x4.(n_stairway(x3) & on(e1,e2) & in(e2,x4) & n_building(x4) & Theme(e2,x3) & Actor(e2,x2) & v_construct(e2) & Actor(e1,x1) & v_work(e1) & n_man(x1))
exists e1 s1 x1 x2.(a_down(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_fall(e1) & n_stair(x2) & n_man(x1))