anchor.diff:               " by "
                (str (poem-author poem)))
              (:div :class "show-button"
  -             (render-link (f_% (setf (mode widget) :show))
  +             (render-link (f_% (setf (mode widget) :show)
  +                               (mark-dirty widget))
                             "Show"))))))))
   
   (defun make-foldable-poem-widget (poem poem-widget-class mode)
  
positive.code: 
  (in-package :website)
  
  ;;;
  
negative.code:     (:show
       (with-html
         (:div :class "dismiss-button"
           (render-link (f_% (setf (mode widget) :folded)
                             (mark-dirty widget))
                        "Hide"))
         (render-widget (poem-widget widget))))
      (:folded
  