anchor.diff:    (loop for chunk in chunks when (not (symmetrical-p chunk)) do (unpair chunk original-p)))
   
   (defun unpair-short (chunks original-p)
  -  (loop for chunk in chunks when (< (length (textified chunk)) 3)
  +  "Unpair chunks whose pair "
  +  (loop for chunk in chunks when (< (length (textified chunk)) *short-length*)
        do (unpair chunk original-p)))
   
   (defun unpair (chunk original-p)
  
positive.code: (defun combine-chunks (&rest chunks)
    (make-instance 'chunk :markup (apply #'append (mapcar #'markup chunks))))
  
  (defun paragraphs (file)
    "Split file into chunks, one per paragraph."
    (loop for p in (rest (parse-file file :parse-links-p nil))
         for i from 0
         for markup = (list p)
         collect (make-chunk markup)))
  
  (defmethod print-object ((o chunk) stream)
    (print-unreadable-object (o stream :type t)
  
negative.code: (in-package :com.gigamonkeys.prose-diff)
  
  (defparameter *short-length* 5)
  
  (defclass chunk ()
    ((markup :initarg :markup :accessor markup)
  