anchor.diff:     (contact-name :initarg :contact-name
   		 :accessor invoice-contact-name)
      (check-in-accounting :initarg :check-in-accounting
  -			:accessor invoice-check-in-accounting)
  +			:accessor invoice-check-in-accounting
  +			:initform '())
      (item-list :initarg :itemlist
   	      :accessor invoice-item-list)
      (root-dir :initarg :root-dir
  
positive.code:     ((null b) nil)
      (t
        (cons (list (car b) (cadr b) (third b)) (picture-list (cdddr b))))))
  
negative.code:    (description :initarg :description
  		:accessor item-description)
     (invoices-on :initarg :invoices-on
  		:accessor item-invoices-on
  		:initform '())
     (picture    :initarg :pictures
  		:accessor item-picture)
     (shows-on :initarg :shows-on
  	     :accessor item-shows-on
  	     :initform '())
     (returned-on :initarg :returned-on
  		:accessor item-returned-on)))
  
  