anchor.diff:  ;;;; aux-param-specs = ( bind-name keyword given-p lambda-spec doc-string)
   ;;;; rest-param-specs = ( name doc-string ) | nil
   (eval-when (:compile-toplevel :load-toplevel :execute)
  -  (defun %parse-documented-lambda-list (lambda-list)
  +  (defun %parse-documented-lambda-list (lambda-list &key (error-on-missing-doc t))
       
       ;; find the locations of each of the lambda keywords
       ;; and grab the ordinary, special (key and aux) and rest args
  
positive.code: 	
  	;; make sure that each element is a list and that
  	;; the last element is a string
  	(mapcar #'(lambda (e)
  		    (check-type e list)
  		    (assert (> (length e) 1) (e) "You *must* supply a documentation string")
  		    (check-type (car (last e)) string))
  		(append ordinary-args optional-args rest-args special-args))
  	
  	(list :positional (append ordinary-args optional-args)
  	      :named special-args
  
negative.code: 
  (implement-concept 
      (foobar impl-generic "GENERIC foobar implementation" :default-implementation t)
    ( x y )
    (- x y))
  
  
  