anchor.diff:    (let ((day-names '("Monday" "Tuesday" "Wednesday"
                        "Thursday" "Friday" "Saturday" "Sunday")))
       (multiple-value-bind
  -        (second minute hour date month year day-of-week dst-p tz)
  +          (second minute hour date month year day-of-week dst-p tz)
           (get-decoded-time)
         (declare (ignore dst-p))
         (format nil "~a ~d/~2,'0d/~d ~2,'0d:~2,'0d:~2,'0d (GMT~@d)"
  
positive.code:                              t)))
         (gtk-container-add window box)
         (gtk-box-pack-start box canvas)
         (gtk-box-pack-start box step-button)
         (gtk-box-pack-start box add-button)
         (gtk-widget-show-all window)))))
  
negative.code:                                 :width-request +canvas-width+
                                  :height-request +canvas-height+))
           (box (gtk-box-new :vertical 2))
           (run-button (gtk-button-new-with-label "Start"))
           (add-button (gtk-button-new-with-label "Add")))
       (labels ((update (&optional widget)
                  (declare (ignore widget))
                  (dolist (ball balls) (update-ball ball))
                  (gtk-widget-queue-draw canvas)
                  t))
         (g-signal-connect window "destroy" (lambda (widget)
                                              (declare (ignore widget))
                                              (leave-gtk-main)))
         (g-signal-connect run-button "clicked"
                           (lambda (widget)
                             (declare (ignore widget))
                             (g-timeout-add (floor (* 1000 +time-step+))
                                            #'update)))
         (g-signal-connect add-button "clicked"
                           (lambda (widget)
                             (declare (ignore widget))
  