|
|
aatu.koskensilta@xxxxxxxxx wrote:
> Rupert wrote:
> > There is no definable well-ordering of the reals.
>
> That's certainly true. It is consistent with ZFC that there is a
> definable well-ordering of the universe (and thus also of the reals),
> though.
>
I may have expressed myself poorly. I think the result I wanted to cite
was "no expression can be proved in ZF to define a well-ordering of the
reals, assuming that ZF is consistent." Is that known?
> --
> Aatu Koskensilta (aatu.koskensilta@xxxxxxxxx)
>
> "Wovon man nicht sprechen kann, daruber muss man schweigen"
> - Ludwig Wittgenstein, Tractatus Logic-Philosophicus
|
|