8.3.3: uncovered Xml2 functionality

Hi,
in 8.3.3 Documentation / F.34.Xml2 the Deprecation notice claims:
"..the core server now covers XML syntax checking and XPath queries, 
which is what Xml2 does, and more."

I can't get boolean values out from function "xpath". I think there is a 
missing implementation of xpath syntax.

Try for example:
select xpath('false()',xml('<root/>'));
select xpath('1=1',xml('<root/>'));
select xpath('boolean(WHATEVERYOUWANT)',xml('<root/>'));

We have to keep in mind that xpath queries can return 4 value types: 
integer, string, boolean and nodeset.
The previous Xml2 implementation was way more comfortable (functions: 
xpath_number, xpath_string, xpath_bool and xpath_nodeset).

Thank you