Query with multiple variables

Create a list of all the title-author pairs, with each pair enclosed in a result element.

<results>
 {
   for $b in doc("bib.xml")/bib/book,
     $t in $b/title,
     $a in $b/author
   return
    <result>
    { $t }
    { $a }
    </result>
  }
</results>

Adapted from XML Query Use Cases