Example 1

<setlist>
   <list>
      <s>apples</s>
      <s>oranges</s>
      <s>wiper blades</s>
   </list>
   <i>2</i>
   <s>bassoons</s>
</setlist>

This expression results in the following list and returns null.

<list>
   <s>apples</s>
   <s>oranges</s>
   <s>bassoons</s>
</list>