A man does work on a stone part of a building.
A construction worker is working on a building.
just because a man does work on a stone part of a build doesn't imply he is a construction worker
exists e1 x1 x2 x3 x4.(on(e1,x2) & of(x2,x4) & n_building(x4) & n_part(x2) & of(x2,x3) & n_stone(x3) & Actor(e1,x1) & v_work(e1) & n_man(x1))
exists e1 x1 x2 x3.(on(e1,x3) & n_building(x3) & Actor(e1,x1) & v_work(e1) & n_worker(x1) & of(x1,x2) & n_construction(x2))