(:extraire le patron V DET N :)
for $b in doc("bao2_3208.txt")//item

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