Example: Multiple <ditavalref> elements in a reference to a
    map
  
  This section is non-normative.
In this scenario, multiple instances of the <ditavalref> element
    are specified in a reference to a map. This is equivalent to referencing that map multiple
    times, with each reference nesting one of the <ditavalref>
    elements.
Example
This section is non-normative.
In the following example, other.ditamap is referenced by a root map.
        The <ditavalref> elements provide conflicting sets of filter
        conditions.
<topicref href="parent.dita">
  <topicref href="other.ditamap" format="ditamap">
    <ditavalref href="audienceA.ditaval"/>
    <ditavalref href="audienceB.ditaval"/>
    <ditavalref href="audienceC.ditaval"/>
  </topicref>
</topicref>This markup is functionally equivalent to referencing other.ditamap
        three times, with each reference including a single <ditavalref>
        elements. The fragment could be rewritten as:
<topicref href="parent.dita">
  <topicref href="other.ditamap" format="ditamap">
    <ditavalref href="audienceA.ditaval"/>
  </topicref>
  <topicref href="other.ditamap" format="ditamap">
    <ditavalref href="audienceB.ditaval"/>
  </topicref>
  <topicref href="other.ditamap" format="ditamap">
    <ditavalref href="audienceC.ditaval"/>
  </topicref>
</topicref>