Did a little more development with Scheme / Racket and Shut the Box. I fixed a few bugs in the previous implementation where you could remove tiles by flipping unflipped tiles before the flipped tiles are checked. I also put in a check so that the tiles that are flipped set a flag so additional tiles can't be flipped.

```
#lang racket
#| Init Block |#
(define tiles '())
(define die1 0)
(define die2 0)
(define turn-number 1)
(define took-turn #f)
(define (start-game)
(set! tiles '(1 2 3 4 5 6 7 8 9)))
(define (dice)
(+ 1 (random 6)))
(define (dice-roll)
(set! die1 (dice))
(set! die2 (dice)))
(define (sum-of-dice)
(+ die1 die2))
(define (sum-of-tiles tilelist)
(apply + tilelist))
(define (list-check l1 l2)
(andmap (lambda (x) (not (boolean? (memq x l2)))) l1))
(define (shut-tiles tilelist)
(if (not took-turn)
(if (list-check tilelist tiles)
(for ([i tilelist])
(if (index-of tiles i)
(begin
(set! tiles (remove i tiles))
(set! took-turn #t))
(error "Tile already shut")))
(error "Tile not available to be shut"))
(error "Already took your turn")))
(define (check-roll dice-sum tile-sum)
(= dice-sum tile-sum))
(define (player-turn tilelist)
(if (check-roll (sum-of-dice) (sum-of-tiles tilelist))
(shut-tiles tilelist)
(print "Roll does not equal shut tiles. Try again.")))
(start-game)
(dice-roll)
(define (next-turn)
(set! turn-number (+ 1 turn-number))
(set! took-turn #f)
(dice-roll)
(show-turn))
(define (show-turn)
(printf "Turn: ")
(println turn-number)
(println tiles)
(printf "Dice roll ~v ~v = ~v" die1 die2 (sum-of-dice) ))
```