Report: ChatGTP generates a valid Schematron schema!

I had a striking conversation with a colleague  yesterday.

He said he needed to add a constraint to a Schematron schema to check for
some uniqueness constraint on a value.  He has not been a developer for
many years, and never an XSLT/XPath/Schematron developer, and his in-house
Schematron developer had left for the day.

On impulse, he asked ChatGTP for a Schematron schema to check uniqueness,
and he reported that it gave a result with instructions, which he was able
to type in directly, and it worked!

I think the reason for this is that the human-language assertion texts
provides exactly the kind of simple statements that ChatGTP likes. (On this
basis, you would expect that ChatGTP would not do as good a job with other
schema languages which disconnect or discourage specifying both
implementation and intent?)

I will get more info on the details later, but it is a pretty interesting
thing.

I had previously tried ChatGTP and found that it gave really good answers
to how to run a Schematron validation step by step, and how to make a
simple assertion. (But it gave a word salad for what the rare attribute @flag
does.)

Regards
Rick