for $item in collection("sortie-treetagger-3208.txt.xml")//item
for $element in $item //element 
let $sonfere := $element/following-sibling::element[1]
where $element/data[1] = "NOM" and $sonfere/data[1] = "ADJ"
return concat($element/data[3],' ',$sonfere/data[3])