anchor.diff:  
   (defclass threefish1024 (cipher 128-byte-block-mixin)
     ((key :accessor threefish-key
  -        :type '(simple-array (unsigned-byte 64) (17)))
  +        :type (simple-array (unsigned-byte 64) (17)))
      (tweak :accessor threefish-tweak
             :initform (make-array 3
                                   :element-type '(unsigned-byte 64)
                                   :initial-contents '(0 0 0))
  -          :type '(simple-array (unsigned-byte 64) (3)))))
  +          :type (simple-array (unsigned-byte 64) (3)))))
   
   (defmethod shared-initialize :after ((cipher threefish1024) slot-names
                                        &rest initargs
  
positive.code: 
  (defclass threefish256 (cipher 32-byte-block-mixin)
    ((key :accessor threefish-key
          :type '(simple-array (unsigned-byte 64) (5)))
     (tweak :accessor threefish-tweak
            :initform (make-array 3
                                  :element-type '(unsigned-byte 64)
                                  :initial-contents '(0 0 0))
            :type '(simple-array (unsigned-byte 64) (3)))))
  
  (defmethod shared-initialize :after ((cipher threefish256) slot-names
                                       &rest initargs
  
negative.code: 
  (defclass threefish512 (cipher 64-byte-block-mixin)
    ((key :accessor threefish-key
          :type (simple-array (unsigned-byte 64) (9)))
     (tweak :accessor threefish-tweak
            :initform (make-array 3
                                  :element-type '(unsigned-byte 64)
                                  :initial-contents '(0 0 0))
            :type (simple-array (unsigned-byte 64) (3)))))
  
  (defmethod shared-initialize :after ((cipher threefish512) slot-names
                                       &rest initargs
  