fun reglist xs n = let
                      val rownil = n div 3 * 3
                      val rowone = rownil + 1
                      val rowtwo = rowone + 1

                      val colnil = n mod 3 * 3
                      val colone = colnil + 1
                      val coltwo = colone + 1
                    in
                      [ List.nth((List.nth(xs, rownil)), colnil), List.nth((List.nth(xs, rownil)), colone), List.nth((List.nth(xs, rownil)), coltwo),
                        List.nth((List.nth(xs, rowone)), colnil), List.nth((List.nth(xs, rowone)), colone), List.nth((List.nth(xs, rowone)), coltwo),
                        List.nth((List.nth(xs, rowtwo)), colnil), List.nth((List.nth(xs, rowtwo)), colone), List.nth((List.nth(xs, rowtwo)), coltwo) ]
                    end;