On Wed, Dec 29, 2021 at 10:27 AM Martin Honnen martin.honnen@xxxxxx
<mailto:martin.honnen@xxxxxx> <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx
<mailto:xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>> wrote:

 >B  I don't have to know one, I just pointed out that the spec doesn't
 >B B  guarantee the order. Thus I don't see why, given the spec, one

>B B expect any implementation to preserve the order.

I am happy to state that the provided solution produces the correct
result on all currently-existing XPath engines :)

As if you had or could verify that. As I said, eXist-db is struggling
with generate-id based approaches, at least if nodes from different
document (fragments?) are involved.