anchor.diff:      package))
   
   (defun find-symbol (string &optional (package *package*))
  +  (check-type string string)
     (let ((p (find-package-or-die package)))
       (multiple-value-bind (sym present-p)
           (gethash string (package-internal-symbols p))
  
positive.code: 	((:internal :external)
  	 ;; TODO: Restarts unintern-old-symbol and don't import.
  	 (error "Newly imported symbol ~S conflicts with present symbol ~S." symbol existing-symbol))))
      (unless (eql symbol (gethash (symbol-name symbol) (package-external-symbols package)))
        (unless (eql symbol (gethash (symbol-name symbol) (package-internal-symbols package)))
          (setf (gethash (symbol-name symbol) (package-internal-symbols package)) symbol)))
      (unless (symbol-package symbol)
        (setf (symbol-package symbol) package))))
  
  
negative.code:     (shadow-one-symbol symbol package))
    t)
  
  (defun package-shortest-name (package)
    (let ((name (package-name package)))
      (dolist (nick (package-nicknames package))
        (when (< (length nick) (length name))
          (setf name nick)))
      name))
  
  (defun initialize-package-system ()
    (write-line "Initializing package system.")
    ;; Create the core packages.
  