anchor.diff:  
   (defmacro defprimitive (name value)
     `(extend *global-env* ',name ,value))
  +
  +(defmacro defprimop (name lambda-list &body body)
  +  `(defprimitive ,name
  +       (make-clutter-operator
  +        :name ,name
  +        :function (lambda ,lambda-list ,@body))))
  +
  +(defmacro defprimfun (name lambda-list &body body)
  +  `(defprimitive ,name
  +       (make-function
  +        (make-clutter-operator
  +         :name ,name
  +         :function (lambda ,lambda-list ,@body)))))
   
   (defprimitive vau
       (make-clutter-operator
  
positive.code: (defun make-symbol-operator (operator)
    (make-clutter-symbol-operator :operator operator))
  
  (defun get-current-env () *denv*)
  
  (defun invoke (operator env args)
  
negative.code:                               variables values))))
  
  (defvar *denv* nil)
  (defstruct clutter-operator function name)
  (defun make-operator (variables body env)
    (make-clutter-operator 
     :function
  