anchor.diff:         (cl:defpackage ,name ,@options)
        ,@(if (member :use options :key #'car)
              `((setf (gethash ,(intern (string name) :keyword) *package-use*)
  -                   (cdr (assoc :use ',options))))
  +                   ',(loop for use in (cdr (assoc :use options))
  +                           when (keywordp use)
  +                             collect use
  +                           else
  +                             collect (intern (string use) :keyword))))
              nil)))
   
   (defmacro in-package (name)
  
positive.code:                      ,@readtable-options)
                     (in-readtable ,name))
                  '(in-readtable nil))))))
  
negative.code: (defpackage cl21.core.package
    (:use :cl)
    (:shadow :in-package
             :use-package
             :defpackage)
    (:import-from :cl21.core.readtable
                  :get-package-readtable-options)
    (:import-from :named-readtables
                  :defreadtable
                  :find-readtable
                  :in-readtable)
    (:import-from :alexandria
                  :ensure-list)
    (:export :package
             :export
             :find-symbol
  