(:extraire le patron ADJ NC :)
for $b in doc("bao2_3208.txt")//item


let $frere := $b/following-sibling::item[1] where $b/a[4] = "ADJ" and $frere/a[4] = "NC"
return <patron>{$b/a[2]/text(), ' ', $frere/a[2]/text()}</patron>