anchor.diff:  (in-package :serapeum/internal-definitions)
   
   (defvar *subenv*)
  -(defvar *orig-form*)
   
   (defmacro nonlocal (&body body)
     `(progn ,@body))
  
positive.code:     (with-collector (seen)
        (loop (unless forms
                (return))
              (let ((*orig-form* (pop forms)))
                ;; NB This `restart-case' has no associated
                ;; signals or handlers: we're using the
                ;; continuations directly.
                (restart-case
                    (seen (expand-partially self *orig-form*))
                  ;; This is used to (recursively) flatten
                  ;; progns into top-level forms.
                  (splice (spliced-forms)
  
negative.code: 
  The `local' macro is loosely based on Racket's support for internal
  definitions."
    (let (*subenv*)
      (multiple-value-bind (body decls) (parse-body orig-body)
        (catch 'local
          (generate-internal-definitions
  