anchor.diff:  ;;; prefix for generalized array operations.
   
   (defsubst tally (array)
  +  "Return the total size of ARRAY, a generalized array.
  +For a true array this is equivalent to `array-total-size'."
     ;; (reduce #'* (shape array))
     (typecase array
       (sequence (length array))
  
positive.code:     (otherwise nil)))
  
  (defsubst valence (array)
    ;; (tally (shape array))
    (typecase array
      (sequence 1)
  
negative.code:     (t 0)))
  
  (defsubst shape (array)
    "Return the shape of ARRAY, a generalized array.
  For a true array this is equivalent to `array-dimensions'."
    (typecase array
      (sequence (list (length array)))
      (array (array-dimensions array))
  