http://www.w3.org/TR/xexpr/

Briefing looking over this w3c request; i feel that this already exist, and
it's call xsl.

But a lot of these tags could be consider as add on in both xsl and xQuery for
farther control, and manipulation over the XML elements and or contents.

Please take this in consideration.

Also this could be of help to XForms processing.

Please take this into consideration.

Thank you for taking the time to read this.

E-S4L