for $c in fn:doc("mondial.xml")//country
let $maxprov := $c/province[population[last()] =
                  max($c/province/population[last()])],
    $maxcity := $c/city[population[last()] =
                  max($c/city/population[last()])]
return
  <country name = "{string($c/name)}"
     maxthing = "{ if($c/province)
                   then $maxprov/name[1]
                   else $maxcity/name[1]
                 }"
     maxpop   = "{ if($c/province)
                   then $maxprov/population[last()]
                   else $maxcity/population[last()]
                 }"/>