An adult sweeping stone staircase outdoors.
An adult is cleaning their outside stairs.
Though it seems to be quite clear, the adult may have not been cleaning the outside stairs.
exists s1 x1 x2 x3 x4.(a_topic(x1) & n_outdoors(x1) & of(x1,x4) & n_staircase(x4) & of(x1,x3) & n_stone(x3) & a_sweeping(s1) & Theme(s1,x1) & of(x1,x2) & n_adult(x2))
exists e1 s1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_clean(e1) & n_stair(x2) & a_outside(s1) & Theme(s1,x2) & of(x2,x1) & n_thing(x1) & n_adult(x1))