anchor.diff:                                variables values))))
   
   (defvar *denv* nil)
  -(defstruct clutter-operator function)
  +(defstruct clutter-operator function name)
   (defun make-operator (variables body env)
     (make-clutter-operator 
      :function
  
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: 
  (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
  