anchor.diff:        fact)))
   
   (defun read-format-subchunk (reader size)
  +  "Reads format subchunk of size SIZE from reader"
     (let ((subchunk (make-format-subchunk)))
       (setf (format-audio-format subchunk)
             (read-bits 16 reader)
  
positive.code:     chunks))
  
  (defun read-wav-header (stream)
    (let* ((reader (read-chunk-header
                    (make-reader :stream stream)))
           (header-subchunks (read-subchunks reader))
  
negative.code:   reader)
  
  (defun read-fact-subchunk (reader size)
    "Reads fact subchunk of size SIZE from reader"
    (let ((fact (make-fact-subchunk :samples-num (read-bits 32 reader))))
      (if (/= size 4) (error 'wav-error-subchunk
                             :message "Fact subchunk size is not 4. Do not know what to do"
  