* The following function sleeps in parallel; it will be finished in 1 second if your system has at least 2 cores:
<pre class='brush:xquery'>
xquerylet $f :fork-join( for $i in 1 to 2 return = function() { prof:sleep(1000) }return xquery:fork-join(($f, $f))
</pre>
* In the following query, up to four URLs will be requested in parallel: