(:Patron morpho-syntaxique : NOM PREP NOM PREP:)
for $element in collection('corpus_3232')//item/descendant::element,
    $prp in $element/following::*[1]/data[contains(text(), 'PRP')],
    $nom in $prp/following::*[3]/data[contains(text(),'NOM')],
    $prp2 in $nom/following::*[3]/data[contains(text(), 'PRP')]

return if ($element/data[contains(text(), 'NOM')]) 
then string-join(($element/data[3]/text(), ' ', $element/following::*[3]/text(), ' ', $nom/following::*[2]/text(), ' ', $prp2/following::*[2]/text()))