anchor.diff:        (with-output-as-presentation
   	  (pane stack-frame 'stack-frame :single-box t)
   	(slim:row
  -	  (slim:cell
  -	    (with-drawing-options (pane :ink clim:+grey41+)
  -	      (format pane "~A: " (frame-no stack-frame))))
  -	  (slim:cell
  -	    (present stack-frame 'stack-frame :view (view stack-frame))))))))
  +	  (with-drawing-options (pane :ink clim:+gray41+)
  +	    (slim:cell (format pane "~A: " (frame-no stack-frame))))
  +	  (with-drawing-options (pane :ink (if (= (frame-no stack-frame)
  +						  (active-frame pane))
  +					       clim:+red4+ clim:+blue4+))
  +	    (slim:cell (present stack-frame 'stack-frame
  +				:view (view stack-frame)))))))))
   
   (defun print-stack-frame-header (object stream)
     (let* ((frame-string (frame-string object))
  
positive.code: 
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;   Commands   ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  
  
negative.code: 
  (defclass debugger-pane (application-pane)
    ((condition-info :reader  condition-info :initarg :condition-info)
     (active-frame :accessor active-frame :initform 0)
     (shown-frames :accessor shown-frames :initform 5)))
  
  (defun make-debugger-pane ()
  