libxml2-2.7.7/test/relaxng/tutor9_7.rng

<grammar xmlns="http://relaxng.org/ns/structure/1.0">

  <include href="inline2.rng"/>

  <start>
    <element name="doc">
      <zeroOrMore>
	<element name="p">
	  <ref name="inline"/>
	</element>
      </zeroOrMore>
    </element>
  </start>

  <define name="inline.class" combine="choice">
    <choice>
      <element name="code">
	<ref name="inline"/>
      </element>
      <element name="em">
	<ref name="inline"/>
      </element>
    </choice>
  </define>
  
</grammar>