anchor.diff:          result))))
   
   (defun read-preserving-whitespace (&optional input-stream (eof-error-p t) eof-value recursive-p)
  -  (read-common (follow-stream-designator input-stream *standard-input*)
  +  (read-common (frob-input-stream input-stream)
                  eof-error-p
                  eof-value
                  recursive-p))
  
positive.code: 
  (defun read (&optional input-stream (eof-error-p t) eof-value recursive-p)
    "READ parses the printed representation of an object from STREAM and builds such an object."
    (let ((stream (follow-stream-designator input-stream *standard-input*)))
      (with-stream-editor (stream recursive-p)
        (let ((result (read-common stream
                                   eof-error-p
  
negative.code:     (:invert (if (upper-case-p c)
                   (char-downcase c)
                   (char-upcase c)))))
  
  (defun whitespace[2]p (char &optional (readtable *readtable*))
    "Test if CHAR is a whitespace[2] character under READTABLE."
  