anchor.diff:  
   (defmacro defun/cc (name arguments &body body)
     `(progn
  -     (setf (fdefinition/cc ',name) (make-instance 'closure/cc
  -                                                  :code (walk-form '(lambda ,arguments ,@body) nil nil)
  -                                                  :env nil))
  +     (setf (fdefinition/cc ',name 'defun/cc)
  +           (make-instance 'closure/cc
  +                          :code (walk-form '(lambda ,arguments ,@body) nil nil)
  +                          :env nil))
        (defun ,name ,arguments
          (declare (ignorable ,@(extract-argument-names arguments :allow-specializers nil)))
          (error "Sorry, /CC function are not callable outside of with-call/cc."))))
  
positive.code:       env))
  
      ((and (symbolp (operator func))
            (fdefinition/cc (operator func)))
       (evaluate-arguments-then-apply
        (lambda (arguments)
          (apply-lambda/cc (apply (fdefinition/cc (operator func)) arguments) arguments k))
        (arguments func) '()
        env))
         
  
negative.code:   (remhash function-name *cc-functions*))
  
  (defun fdefinition/cc (function-name)
    (values-list (gethash function-name *cc-functions*)))
  
  (defun (setf fdefinition/cc) (closure-object function-name &optional (type 'defun/cc))
    (setf (gethash function-name *cc-functions*) (list closure-object type)))
  
  (defvar *debug-evaluate/cc* nil
    "When non NIL the evaluator will print, at each evaluation
  