| Or(xf1, xf2), Or(yf1, yf2)
| And(xf1, xf2), And(yf1,yf2) -> (xf1 == yf1) && (xf2 == yf2)
| Move(d1, p1, s1), Move(d2 ,p2 ,s2) -> d1 == d2 && p1 == p2 && s1 == s2
| Or(xf1, xf2), Or(yf1, yf2)
| And(xf1, xf2), And(yf1,yf2) -> (xf1 == yf1) && (xf2 == yf2)
| Move(d1, p1, s1), Move(d2 ,p2 ,s2) -> d1 == d2 && p1 == p2 && s1 == s2