A woman is working on an ice sculpture.
A woman is sculpting something out of ice.
A woman working on an ice sculpture would have to be sculpting.
exists e1 x1 x2 x3.(on(e1,x2) & n_sculpture(x2) & of(x2,x3) & n_ice(x3) & Actor(e1,x1) & v_work(e1) & n_woman(x1))
exists e1 x1 x2 x3 x4.(Theme(e1,x2) & Actor(e1,x1) & v_sculpt(e1) & of(x3,x4) & n_ice(x4) & out(x2,x3) & n_thing(x3) & n_thing(x2) & n_woman(x1))