anchor.diff:                   *royco-minut-soup*
                    *20-minutes/1499/facile*
                    *metrofrance/694/moyen*
  +                 *20-minutes/1501/difficile*
                    ))
     (multiple-value-bind (solutions tries) (sudoku-solver sudoku)
       (terpri)
  
positive.code:     (map nil 'sudoku-print solutions)))
  
  
  ;;;; THE END ;;;;
  
negative.code:                                            (3 2 x x x 4 x x x)
                                             (x 1 7 x 9 8 4 x 3)))
  
  (defparameter *20-minutes/1501/difficile* #2A((x 1 5 x 8 9 x x x)
                                                (2 x 6 3 x 5 x x x)
                                                (x 7 x x x x x 8 x)
                                                (x 6 9 x x 1 x x 3)
                                                (x x x 8 x 3 x x x)
                                                (3 x x 6 x x 2 9 x)
                                                (x 9 x x x x x 2 x)
                                                (x x x 9 x 6 1 x 5)
                                                (x x x 7 1 x 9 3 x)))
  
  (defparameter *metrofrance/694/moyen* #2A((x x 1 2 x x x x 8)
                                            (x x x x 5 1 x x 3)
                                            (x 7 x x x x 6 x 1)
  