anchor.diff:       when (not (null (cdr pair)))
      collect pair))
   
  +
   (defun display-dispatch (value render-alist)
     (if (typep value 'display-object)
         value ; already displayed
         ;; otherwise needs to display
  -      (let ((data (combine-render (cons `("text/plain" . ,(render-plain value)) ; at least text/plain encoding is required
  +      (let ((data (combine-render 
  +         (cons `("text/plain" . ,(render-plain value)) 
   					render-alist))))
   	(make-instance 'display-object :value value :data data))))
   
   
   (defun display (value)
     "Display VALUE in all supported representations."
  -  (display-dispatch value  `(("text/html" . ,(render-html value))
  -			     ("text/markdown" . ,(render-markdown value))
  -			     ("text/latex" . ,(render-latex value))
  -			     ("image/png" . ,(render-png value))
  -			     ("image/jpeg" . ,(render-jpeg value))
  -			     ("image/svg+xml" . ,(render-svg value))
  -			     ("application/json" . ,(render-json value))
  -			     ("application/javascript" . ,(render-javascript value)))))
  +  (display-dispatch value  
  +     `(("text/html" . ,(render-html value))
  +	   ("text/markdown" . ,(render-markdown value))
  +	   ("text/latex" . ,(render-latex value))
  +	   ("image/png" . ,(render-png value))
  +	   ("image/jpeg" . ,(render-jpeg value))
  +	   ("image/svg+xml" . ,(render-svg value))
  +	   ("application/json" . ,(render-json value))
  +	   ("application/javascript" . ,(render-javascript value)))))
  +
   
   (defun display-html (value)
     "Display VALUE as HTML."
     (display-dispatch value `(("text/html" . ,(render-html value)))))
   
  +
   (defun display-markdown (value)
     "Display VALUE as MARDOWN text."
     (display-dispatch value `(("text/markdown" . ,(render-markdown value)))))
   
  +
   (defun display-latex (value)
     "Display VALUE as a LATEX document."
     (display-dispatch value `(("text/latex" . ,(render-latex value)))))
   
  +
   (defun display-png (value)
     "Display VALUE as a PNG image."
     (display-dispatch value `(("image/png" . ,(render-png value)))))
   
  +
   (defun display-jpeg (value)
     "Display VALUE as a JPEG image."
     (display-dispatch value `(("image/jpeg" . ,(render-jpeg value)))))
   
  +
   (defun display-svg (value)
     "Display VALUE as a SVG image."
     (display-dispatch value `(("image/svg+xml" . ,(render-svg value)))))
   
  +
   (defun display-json (value)
     "Display VALUE as a JSON document."
     (display-dispatch value `(("application/json" . ,(render-json value)))))
   
  +
   (defun display-javascript (value)
     "Display VALUE as embedded JAVASCRIPT."
     (display-dispatch value `(("application/javascript" . ,(render-javascript value)))))
  +
   
   ;;;;;;;;;;;;;;;;;
   ;;; Evaluator ;;;
  
positive.code: 
  ;; XXX: should be a defconstant but  strings are not EQL-able...
  (defvar +WIRE-IDS-MSG-DELIMITER+ "<IDS|MSG>")
  
  (defmethod wire-serialize ((msg message) &key (identities nil)(key nil))
    (with-slots (header parent-header metadata content) msg
  
negative.code: (defun get-argv ()
    ;; Borrowed from apply-argv, command-line-arguments.  Temporary solution (?)
    #+sbcl (cdr sb-ext:*posix-argv*)
    #+clozure CCL:*UNPROCESSED-COMMAND-LINE-ARGUMENTS*  
    #+gcl si:*command-args*
    #+ecl (loop for i from 0 below (si:argc) collect (si:argv i))
    #+cmu extensions:*command-line-strings*
  