this-is-where-this-ends.xml

<dsig:Transform id="selective"
      Algorithm="http://www.w3.org/TR/1999/REC-xpath-19991116"
      xmlns:dsig="http://www.w3.org/2000/09/xmldsig#">
     <dsig:XPath
      xmlns:pidf="urn:ietf:params:xml:ns:pidf"
      xmlns:gp="urn:ietf:params:xml:ns:pidf:geopriv10"
      xmlns:dep="urn:ietf:params:xml:ns:pidf:geopriv10:dsig"
      xmlns:dm="urn:ietf:params:xml:ns:pidf:data-model">

   <!-- The 'presence' element -->
   (count(self::pidf:presence
             | here()/ancestor::pidf:presence[1]) = 1)

   <!-- The 'tuple' element and all selected descendants -->
   or (((count(ancestor-or-self::pidf:tuple[1]
              | here()/ancestor::pidf:tuple[1]) == 1)
        or (count(ancestor-or-self::dm:device[1]
                 | here()/ancestor::dm:device[1]) == 1)
        or (count(ancestor-or-self::dm:person[1]
                 | here()/ancestor::dm:person[1]) == 1))
       and (self::pidf:tuple or self::dm:device
            or self::dm:person or self::pidf:status
            or ancestor-or-self::pidf:timestamp
            or ancestor-or-self::dm:timestamp
            or ancestor-or-self::dm:deviceID
            or self::gp:geopriv or self::gp:usage-rules
            or ancestor-or-self::gp:method
            or ancestor-or-self::gp:location-info
            or ancestor-or-self::dep:dependability))

   <!-- All attributes (including namespace declarations) -->
   <!-- Needed for elements without ancestor-or-self rules above -->
   or ((count(self::node() | parent::*/attribute::*
              | parent::*/namespace::*) + 1
            == (count(self::node()) + count(parent::*/attribute::*)
                      + count(parent::*/namespace::*)))
       and parent::*[
             (count(self::pidf:presence
                    | here()/ancestor::pidf:presence[1]) = 1)

             or (((count(ancestor-or-self::pidf:tuple[1]
                        | here()/ancestor::pidf:tuple[1]) == 1)
                  or (count(ancestor-or-self::dm:device[1]
                           | here()/ancestor::dm:device[1]) == 1)
                  or (count(ancestor-or-self::dm:person[1]
                           | here()/ancestor::dm:person[1]) == 1))

                 and (self::pidf:tuple or self::dm:device
                      or self::dm:person or self::pidf:status
                      or self::gp:geopriv or self::gp:usage-rules))
           ])
     </dsig:XPath>
   </dsig:Transform>