[r-t] Extension question

[Graham John]

On 6 November 2017 at 17:17, Robin Woolley <robin at robinw.org.uk> wrote:

> Whether it's the only extension is another matter!

If you look at related methods under https://complib.org/method/26928,
you will see that there are other candidate extension constructions,
but none going to Royal, which was Don's example. That's why I said
that it was unique. It is not a requirement in the decisions, but I
also would have thought that an extension construction that works at
every stage would normally be preferred over one that didn't.

Graham