1<grammar xmlns="http://relaxng.org/ns/structure/1.0">
2
3  <define name="inline">
4    <zeroOrMore>
5      <choice>
6	<text/>
7	<element name="bold">
8	  <ref name="inline"/>
9	</element>
10	<element name="italic">
11	  <ref name="inline"/>
12	</element>
13	<ref name="inline.extra"/>
14      </choice>
15    </zeroOrMore>
16  </define>
17
18  <define name="inline.extra">
19    <notAllowed/>
20  </define>
21
22</grammar>
23