<?xml version="1.0" encoding="UTF-8"?>
<doctype>
  <attributeGroup name="e1"/>
  <element>
    <name>x1</name>
    <sequence/>
  </element>
  <attlist>
    <name>x1</name>
    <attribute>
      <name>att</name>
      <cdata/>
      <implied/>
    </attribute>
    <attributeGroupRef name="e1"/>
  </attlist>
  <element>
    <name>x2</name>
    <sequence/>
  </element>
  <attlist>
    <name>x2</name>
    <attributeGroupRef name="e1"/>
  </attlist>
  <element>
    <name>x3</name>
    <sequence/>
  </element>
  <attlist>
    <name>x3</name>
    <attributeGroupRef name="e1"/>
    <attribute>
      <name>att</name>
      <cdata/>
      <implied/>
    </attribute>
  </attlist>
</doctype>
