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