RE: Use of data() function

Not sure what point you're making 

> 
> sure but it also makes sense to say child::sub

of course, and you can.
> 
> I don't think most doc-heads would accept as valid the idea 
> that a mixed content element (especially if the element has 
> the mixed content in it) is of type string.
> 
of course, and it isn't of type string. But if you atomize it you get an
untypedAtomic value which can be used anywhere you might use a string.

Michael Kay
http://www.saxonica.