anchor.diff:  (defun make-instance-standard-generic-function
          (generic-function-class 
           &key 
  -            name 
  +            name
  +            documentation
               lambda-list 
               method-class 
               (method-combination 'standard)
  
positive.code: 
  ;;; ensure method
  
  (defun ensure-method (gf &rest all-keys &key eql-specializers &allow-other-keys)
  	(if (null gf)
  		;; define a generic function on the fly
  		(setf gf 
  
negative.code: (defvar the-slots-of-standard-class) ;standard-class's class-slots
  (defvar the-class-standard-class)    ;standard-class's class metaobject
  
  ;;;
  ;;; This now returns null, rather than signal an error, if the slot is not found.
  ;;; This is to enable further searches for class slots by the functions which
  