anchor.diff:  
   (defparameter *print-circle* t)
   (defparameter *print-pretty* t)
  +(defparameter *debug* nil)
   
   ; Struct node occupies 24 bits for slots and 16 for 1-char key = 40 bits
   (defstruct
  
positive.code:         (if (null symbol)
              (return-from find-seq nil)
              (find-seq symbol (subseq seq 1)))))
  
  (defun add-seq (trie seq &optional (count 1))
      "Add a sequence to the trie count times.
      A count below one is changed to one. Modifies trie in-place."
      (incf (trie-width trie) (max count 1))
      (when (zerop (length seq))
          (return-from add-seq trie))
      (let ((symbol (find-key trie (elt seq 0))))
          (when (null symbol)
              (setf symbol (add-key trie (elt seq 0))))
          (add-seq symbol (subseq seq 1) count)))
  
  ; (defun remove-seq (trie seq &optional (count 1))
  ;     "Remove a sequence from trie"
  
negative.code: 
  (defun test ()
      (setf r (make-trie))
      (add-seqs r '("blow" "boa" "blush" "foo")))
  
  ; Sentence level
  
  