var mediawiki = {
  'b': rr.Node('b', rr.Sequence(rr.Literal("'''"), rr.Ref('wikichunk'), rr.Literal("'''"))),
  'del': rr.Sequence(rr.Literal('<strike>'), rr.Ref('wikichunk'), rr.Literal('</strike>')),
  'h2': rr.Sequence(rr.StartOfLine(), rr.Literal('== '), rr.SingleLineText(), rr.Literal(' =='), rr.EndOfLine()),
  'h3': rr.Node('h3', rr.Sequence(rr.StartOfLine(), rr.Literal('=== '), rr.SingleLineText(), rr.Literal(' ==='), rr.EndOfLine())),
  'h4': rr.Sequence(rr.StartOfLine(), rr.Literal('==== '), rr.SingleLineText(), rr.Literal(' ===='), rr.EndOfLine()),
  'h5': rr.Sequence(rr.StartOfLine(), rr.Literal('===== '), rr.SingleLineText(), rr.Literal(' ====='), rr.EndOfLine()),
  'h6': rr.Sequence(rr.StartOfLine(), rr.Literal('====== '), rr.SingleLineText(), rr.Literal(' ======'), rr.EndOfLine()),
  'hr': rr.Sequence(rr.StartOfLine(), rr.Literal('----'), rr.EndOfLine()),
  'i': rr.Sequence(rr.Literal("''"), rr.Ref('wikichunk'), rr.Literal("''")),
  'nowiki': rr.Sequence(rr.Literal('<nowiki>'), rr.MultiLineText(), rr.Literal('</nowiki>')),
  'text': rr.MultiLineText(),
  'wikichunk': rr.Or(
      rr.Ref('b'),
      rr.Ref('del'),
      rr.Ref('h2'),
      rr.Ref('h3'),
      rr.Ref('h4'),
      rr.Ref('h5'),
      rr.Ref('h6'),
      rr.Ref('hr'),
      rr.Ref('i'),
      rr.Ref('nowiki'),
      rr.Ref('text')
   ),
  'wikidoc': rr.Node('wikidoc', rr.Sequence(rr.ZeroOrMore(rr.Ref('wikichunk')), rr.EndOfText())),
};