anchor.diff:                  (setf norm-square (rotate-square norm-square)))))
           (when (needs-mirror norm-square)
             (setf norm-square (mirror-square norm-square :axis :diagonal))))
  +      (when (= (length (remove-if #'plusp (first (columns norm-square))))
  +               (length (rows norm-square)))
  +        (setq norm-square (mirror-square norm-square :axis :vertical)))
         norm-square)))
   
   (defun square= (square-1 square-2)
  
positive.code:                          (aref square 2 2)
                           (aref square 0 2)))
            (middles (list (aref square 0 1)
                           (aref square 1 2)
                           (aref square 2 1)
                           (aref square 1 0))))
        (flet ((lowest-position (sequence)
                 (position (apply #'min (remove-if #'zerop sequence)) sequence))
               (needs-mirror (square)
  
negative.code:                          (0 0 0))))
        (square= (normalize-square square-1) square-2)) t)
  
  ;;; actual magic squares tests (not just matrix junk)
  
  (defparameter *perfect-square* #2a ((8 1 6)
                                      (3 5 7)
                                      (4 9 2)))
  