anchor.diff:  ;;; Unfortunately, it looks like this is a primitive operation that
   ;;; cannot be implemented with just weak pointers.  CMUCL & SBCL are weak.
   
  -#+(or cmu sbcl)
  -(eval-when (:compile-toplevel :load-toplevel :execute)
  -  (format *error-output*
  -    "~2%WARNING: ~A: WEAK-OR-RELATION should be implemented ~
  -     as primitive in ~A~2%" 'closer-weak (lisp-implementation-type)))
  +;; #+(or cmu sbcl)
  +;; (eval-when (:compile-toplevel :load-toplevel :execute)
  +;;   (warn "~A: ~A is lacking a primitive WEAK-OR-RELATION."
  +;;         'closer-weak (lisp-implementation-type)))
   
   #-(and clisp (not debug-weak))
   (defstruct (weak-or-relation (:constructor %make-weak-or-relation)
  
positive.code: 
  (defun gc ()
    "Calls the garbage collector."
    nil
    #+ccl   (ccl:gc)
    #+clisp (ext:gc)
    #+cmu   (extensions:gc)
  
negative.code:   (test/wl)
    (test/wht))
  
  #-sbcl (test)
  ;; #+sbcl (warn "~A: ~A fails weak-pointer garbage collection tests. Testing is disabled."
  ;;         'closer-weak (lisp-implementation-type))
  
  ;;;; THE END ;;;;
  