Note that on c.l.python, Raymond Hettinger justifies this rejection as follows:

  "the docs are sufficient when they say that set ordering is arbitrary"

Where exactly do the docs say this? I do not see it.
I am looking here: <URL:http://docs.python.org/lib/types-set.html>

I also take this as a concession that the docs *should* say something like this,
which is about half of the language I proposed
(unless there is some reason why 'arbitrary' is superior to 'indeterminate').

Btw, I did provide the source code to several people before Peter.
This was clear in the thread on c.l.python.
I do not think they would appreciate being called "not experienced".