declare namespace cmd = "http://www.clarin.eu/cmd/1";

for $collection in doc("../XML_files/EKUT_CMDI/catalog.xml")/collection/doc,
    $cmdifile in doc(concat("../XML_files/EKUT_CMDI/",$collection/@href)),
    $person in $cmdifile//*:Person
    let $insertauthoritativeids :=  <cmdp:AuthoritativeID>
                        <cmdp:id>http://d-nb.info/gnd/36187-2</cmdp:id>
                        <cmdp:issuingAuthority>GND</cmdp:issuingAuthority>
                     </cmdp:AuthoritativeID>
                     
    where $person//*:firstName="Thorsten" and $person//*:lastName="Trippel"
    return  insert node $insertauthoritativeids as last into $person/*:AuthoritativeIDs