anchor.diff:  
   ;;; 29.4.5 Creating a Standalone CLIM Window
   
  -(define-application-frame a-window-stream () 
  +(define-application-frame a-window-stream ()
     ((the-io))
     (:panes
      (io
  
positive.code:    (user-max-height  :reader pane-user-max-height
                       :type   spacing-value)
     (x-spacing        :reader pane-x-spacing
                       :type spacing-value)
     (y-spacing        :reader pane-y-spacing
                       :type spacing-value)))
  
  ;; The exact behaviour though is different:
  
negative.code:                       :initform nil) ))
  
  (defclass pane (standard-sheet-input-mixin
  		sheet-transformation-mixin
                  layout-protocol-mixin
                  basic-sheet)
    (
     (text-style :initarg :text-style :initform nil :reader pane-text-style)
     (name :initarg :name :initform "(Unnamed Pane)" :reader pane-name)
  