RE: Sibling axis and as="element()"

> *It would be a useful feature if Saxon gave a warning if 
> someone uses a sibling axis on an element in a rootless 
> tree...similar to when the context node is an attribute (if 
> that's feasible)

Saxon confines its warnings to things that can be detected at compile time,
such as getting an attribute of an attribute. This condition can't be
detected early without doing a lot more analysis.

Michael Kay
http://www.saxonica.com/