A rock sculptor working on a rock.
Someone is making a piece of art with a rock.
The rock sculptor may not be creating a piece of art with the rock at all.
exists e1 x1 x2 x3 x4.(a_topic(x1) & on(e1,x4) & n_rock(x4) & Actor(e1,x3) & v_work(e1) & (x1 = x3) & n_sculptor(x1) & of(x1,x2) & n_rock(x2))
exists e1 x1 x2 x3 x4.(Theme(e1,x2) & Actor(e1,x1) & v_make(e1) & with(x2,x4) & n_rock(x4) & of(x2,x3) & n_art(x3) & n_piece(x2) & n_person(x1))