<?SBNF-www.vishia.de version="1.0" encoding="iso-8859-1" ?>
$xmlns:topics="http://www.vishia.de/2006/Topics".
$xmlns:xhtml="http://www.w3.org/1999/xhtml".
$inputEncodingKeyword="encoding".

Topics::=                 
[\<\?Topics<*\ ?>                ##may be start with <?Topics... ident = "name" encoding = "..." attr... = "value..." ?>
  { [?\?\>] ident = <""?@ident> 
  | encoding = <""?@encoding> 
  | <$?attribute> = <""?value> 
  } \?\> 
]
{ <topic2?topics:topic> }.       ##some topic level 2 beginning with == , contains level 3 etc.

topic2::= == <*|==?@title> ==    ##all chars from "==" until " ==" are the title chars.
[@ident=<*\ \r\n?@ident>]              ##the ident of this chapter
<*|\n==|\e?xhtml:body+>          ## all until \n== is content, \n== introduce either a deeper chapter or the end of
  chapter level2
[{ <topic3?topics:topic>}].      ##deeper chapter level 3 follows or not

topic3::= === <*|===?@title> ===
[@ident=<*\ \r\n?@ident>]
<*|\n==|\e?xhtml:body+>
[{ <topic4?topics:topic>}].                    ##deeper chapter level 3 follows or not


topic4::= ==== <*|====?@title> ====
[@ident=<*\ \r\n?@ident>]
<*|\n==|\e?xhtml:body+>
[{ <topic5?topics:topic>}].                    ##deeper chapter level 4 follows or not


topic5::= ===== <*|=====?@title> =====
[@ident=<*\ \r\n?@ident>]
<*|\n==|\e?xhtml:body+>
[{ <topic6?topics:topic>}].                    ##deeper chapter level 4 follows or not


topic6::= ====== <*|======?@title> ======
[@ident=<*\ \r\n?@ident>]
<*|\n==|\e?xhtml:body+>.