    if we let the user know what was going on. */
    return( 0 ) ;
  }

  /* We successfully opened the file.  */
  /* Now we check its protocol number.  Perhaps this document was 
     created by another, later version of this same library--and 
     it might not be compatible with this library.  Normally, 
     incompatible versions use different major protocol numbers. */
  /* If we encounter a document with the wrong protocol number, 
     we reject it and return an error.  Of course, if we encountered