[Exist-open] can't add xmlns:xi attribute to root tag of xml document

[<pat...@or...>]

Hi,
This is my first message here. I'm a happy user of eXist. I've been using it for about a year now.

I need to split an xml document and add xinclude declarations in this document.
So I need to add  to the root tag of my document, a namespace declaration for the xi namespace.
I'm trying to do this:

update insert attribute xmlns:xi {"http://www.w3.org/2001/XInclude"} into $item

But it fails with the following error:
XPST0081: No namespace defined for prefix xmlns

I tried to define the xmlns prefix but then eXist complains that it's not allowed:
err:XQST0070: Namespace predefined prefix 'xmlns' can not be bound

Any idea on how I can add a xmlns:xi=http://www.w3.org/2001/XInclude attribute to the the root tag of my xml document with xquery?

Patrice
















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