for $item in collection("sortie-treetagger-3208.txt.xml")//item
for $element in $item //element 
let $sonfere := $element/following-sibling::element[1]
let $sonfere2 := $element/following-sibling::element[2]
where $element/data[1][contains(text(),"VER")] and $sonfere/data[1][contains(text(),"DET")] and $sonfere2/data[1] = "NOM" 
return concat($element/data[3],' ',$sonfere/data[3],' ',$sonfere2/data[3])