anchor.diff:  	  (list (mapcar
   		 (lambda (var-desc)
   		   (let ((var-sym (->sym (car var-desc))))
  -		     (set-add env var-sym)
   		     (set-add locals var-sym)
   		     (cons (->sym (car var-desc))
   			   (transform-tree (cdr var-desc)))))
  
positive.code: 	    (transform-tree (second form)))))
  ;;
  
  (flet ((dump (el)
  	 (or (and (symbolp el) el) (set-elems el))))
    (defun dump-lexenv-chain (fname)
      (let ((dump (mapcar #'dump *lexenv-chain*)))
        (if fname (cons (list fname) dump)
  	  dump)))
    (defun transform-obj-env (place)
      (setf (car place) (dump (car place)))
      (setf (cdr place) (mapcar #'dump (cdr place)))))
  
negative.code:     (declare (special lmbd-forms))
      (let ((toplevel (shallow-process-toplevel-form ast)))
        (loop until (queue-empty? lmbd-forms)
  	 for (form position lexenv-chain) = (queue-dequeue lmbd-forms) do
  	   (let ((funct-form (shallow-process-function-form form lexenv-chain)))
  	     (setf (car position) (car funct-form)
  		   (cdr position) (cdr funct-form))))
        toplevel)))
  