anchor.diff:  
   ;; This should really have a host associated with it...
   (defvar *default-pathname-defaults* (make-instance 'pathname :host nil))
  +
  +(defmethod initialize-instance :after ((instance pathname) &key)
  +  (assert (pathname-%host instance)))
   
   (defun make-pathname (&key host
                           (device nil devicep)
  
positive.code:                         (type nil typep)
                          (version nil versionp)
                          defaults)
    (if defaults
        (setf defaults (pathname defaults))
        (setf defaults (make-instance (host-pathname-class (pathname-host *default-pathname-defaults*))
                                      :host (pathname-host *default-pathname-defaults*))))
    (make-instance (host-pathname-class (if host (find-host host) (pathname-host defaults)))
                   :host (if host (find-host host) (pathname-host defaults))
                   :device (if devicep device (pathname-device defaults))
                   :directory (if directoryp
                                  (if (eq directory :wild)
                                      '(:absolute :wild-inferiors)
                                      directory)
                                  (pathname-directory defaults))
                   :name (if namep name (pathname-name defaults))
                   :type (if typep type (pathname-type defaults))
                   :version (if versionp version (pathname-version defaults))))
  
  (defun pathname-host (pathname &key (case :local))
    (pathname-%host (pathname pathname)))
  
negative.code:   (mapcar #'second *host-alist*))
  
  (defclass pathname ()
    ((%host :initarg :host :reader pathname-%host)
     (%device :initarg :device :reader pathname-%device)
     (%directory :initarg :directory :reader pathname-%directory)
     (%name :initarg :name :reader pathname-%name)
     (%type :initarg :type :reader pathname-%type)
     (%version :initarg :version :reader pathname-%version))
    (:default-initargs :device nil :directory nil :name nil :type nil :version nil))
  
  (defun pathnamep (object)
  