for $art in collection("sortie-3214-regexp")//article
for $elt in $art/element
let $nextElt := $elt/following-sibling::element[1]
let $nextnextElt := $elt/following-sibling::element[2]
let $nextnextnextElt := $elt/following-sibling::element[3]
where $elt/data[1] = "NOM" and $nextElt/data[1] = "PRP"  and $nextnextElt/data[1]="NOM" and $nextnextnextElt/data[1]="PRP"
return concat($elt/data[3]/text()," ",$nextElt/data[3]/text()," ",$nextnextElt/data[3]/text()," ",$nextnextnextElt/data[3]/text())