<?xml version="1.0"?>
<sparql xmlns="http://www.w3.org/2005/sparql-results#">
  <head>
    <variable name="x"/>
  </head>
  <results>
    <result>
      <binding name="x">
        <uri>http://example.org/x3</uri>
      </binding>
    </result>
  </results>
</sparql>