A sculptor is carving stone.
A sculptor is carving diamonds
It's either stone or diamonds
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_carve(e1) & n_stone(x2) & n_sculptor(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_carve(e1) & n_diamond(x2) & n_sculptor(x1))