anchor.diff:      (yason:encode (dictionary module) stream)))
   
   (defun link-p (definition)
  -  (and (< 2 (length definition))
  +  (and definition (< 2 (length definition))
          (string= definition "=>" :end1 2)
          (string-trim " " (subseq definition 2))))
   
  
positive.code:          (definition (gethash term (dictionary module))))
      (when-let ((link (link-p definition)))
        (setf definition (gethash link (dictionary module))
              term link))
      (respond event (format-message event (format NIL "~a: ~:[Unknown term.~;~:*~a~]" term definition)))))
  
  (defun define-term (module event term definition)
  
negative.code:     (when-let ((link (link-p definition)))
        (let ((definition (gethash link (dictionary module))))
          (when-let ((definition (and definition (link-p definition))))
            (respond event "Cannot link to a link. Linking to ~a instead." definition)
            (setf term definition))))
      (setf (gethash term (dictionary module)) definition)
      (respond event "~:[New~;Old~] term ~:*~:[~;re~]defined." old-definition)))
  
  