anchor.diff:                             ,input))
   
   (defun call-with-input-stream (fn input)
  -  (cond ((typep input 'stream)
  +  (cond ((streamp input)
            ;; There is no way to guarantee that FILE-POSITION will work
            ;; on a stream so let's just read the entire INPUT into a
            ;; string.
            (with-input-from-string (stream (read-stream-into-string input))
              (funcall fn stream)))
  -        ((typep input 'string)
  +        ((stringp input)
            (with-input-from-string (input input)
              (funcall fn input)))
           (t
  
positive.code: ;;;;
  ;;;; - special prompt syntax for forms not to be evaluated when a file
  ;;;;   is loaded
  ;;;;
  ;;;; - pathnames for input/output
  ;;;;
  ;;;; - capture conditions signalled?
  
  
negative.code:                             ,output))
  
  (defun call-with-output-stream (fn output)
    (cond ((streamp output)
           (funcall fn output))
          ((null output)
           (with-output-to-string (stream)
             (funcall fn stream)))
          (t
           (assert nil))))
  
  (defun write-transcript (transcript output &key update-only
                           (include-no-output update-only)
  