anchor.diff:  
   (define-condition symbol-in-missing-package-error (missing-package-error)
     ((symbol-name :initarg :symbol-name)))
  +
  +(define-condition missing-symbol-error (reader-error)
  +  ((symbol-name :initarg :symbol-name)))
  +
  +(define-condition symbol-missing-in-package-error (missing-symbol-error)
  +  ((package-name :initarg :package-name)))
   
   (defun serror (condition stream control-string &rest arguments)
     (error condition
  
positive.code:            "LIST-ALL-MACRO-CHARACTERS"
             "SIMPLE-READER-ERROR" "SIMPLE-END-OF-FILE"
             "MISSING-PACKAGE-ERROR" "SYMBOL-IN-MISSING-PACKAGE-ERROR"
             "INTERN-HERE" "RETURN-UNINTERNED"
             ;; Utilities:
             "POTENTIAL-NUMBER-P")
  
negative.code:                   (multiple-value-bind (sym where) (find-symbol sname pname)
                      (if (eq where :external) 
                          (accept 'symbol sym)
                          (accept 'symbol
                                  (restart-case (error 'symbol-missing-in-package-error
                                                       :stream *input-stream* :package-name pname :symbol-name sname)
                                    (make-symbol (&rest rest)
                                      :report "Make the missing symbol in the specified package"
                                      (declare (ignore rest))
                                      (intern sname pname)))))))
                (accept 'symbol
                        (restart-case (error 'symbol-in-missing-package-error
                                             :stream *input-stream* :package-name pname :symbol-name sname)
  