declare function local:concerto($doc){
       <catalog>
        {
        <total>
            {
            fn:count($doc//book)     
            }
        </total>,
        for $book in $doc//book 
         return (
            <book id='{$book/id | $book/@id }'> 
                {$book/author} 
                <price>{($book/price | $book/@price)/data() }</price>
                <title>{($book/title | $book/@title)/data() }</title>
            </book>)
         }
         </catalog>
	};
 
let $message :=  (
                    local:concerto(doc('http://cin.ufpe.br/~dsmp/xquery/xml/catalog.xml')) 
                 |  local:concerto(doc('http://cin.ufpe.br/~dsmp/xquery/xml/outroCatalogo.xml'))
                 ) 
return {
   $message
}