anchor.diff:      (define-default-superclasses boot)
       (define-reader-method-class boot)
       (define-writer-method-class boot)
  +    (define-ensure-class r2)
       (define-add-method boot)
       (ld "../CLOS/invalidate-discriminating-function.lisp" c1 r1)
       (ld "../CLOS/generic-function-initialization-defmethods.lisp" c1 r1)
  
positive.code: 			 :function function)
  	  do (add-method (sicl-genv:fdefinition writer r) method))))
  
  (defun define-ensure-class-r1 (boot)
    (setf (sicl-genv:fdefinition 'sicl-clos:ensure-class (r1 boot))
  	(lambda (class-name
  		 &key
  		   direct-slots
  
negative.code:     ;; the temporary definition of the macro DEFMETHOD.
      (ld "../CLOS/make-method-lambda-support.lisp" c1 c1)
      (ld "../CLOS/ensure-method.lisp" c1 r1)
      (define-ensure-class r1)
      (message "Finished customizing environments for phase 1~%")))
  
  (defun customize-for-phase2 (boot)
  