Does fn:data preserve order for list types?

Suppose $e is bound to an element that looks like this:

         <e xsi:type="xs:integer">1 2 3 4 5</e>

Now consider the following expression:

         data($e)

Is an implementation required to return the values in the original order? 
Would an implementation be conformant if it returned 5 4 3 2 1? I believe 
our answer is "yes", but I can't find where our specs say so clearly.

Jonathan