A man works on installing a floor.
The man is working on the floor.
in both sentences, a man is working / works on a floor.
exists e2 e1 x1 x2 x3.(on(e1,e2) & Theme(e2,x3) & Actor(e2,x2) & v_install(e2) & n_floor(x3) & Actor(e1,x1) & v_work(e1) & n_man(x1))
exists e1 x1 x2.(n_floor(x2) & n_man(x1) & on(e1,x2) & Actor(e1,x1) & v_work(e1))