[FOM] Woodin's pair of articles on CH

T.Forster@dpmms.cam.ac.uk T.Forster at dpmms.cam.ac.uk
Wed Jan 13 17:23:31 EST 2010

On Jan 13 2010, William Tait wrote:In the other 
> direction, a hereditarily countable set can be coded (not necessarily 
> uniquely) by a well-founded tree whose nodes are natural numbers, which 
> in turn can be coded by a set of natural numbers. The relation between 
> two trees representing the same hereditarily countable set is definable 
> in NT^2.

Is this the coding that is in play, as it were, in Woodin's thinking?

> I may be misremembering, but I think that Steve Simpson wrote a paper 
> bearing on this in one of the past centuries.

Probably the 20th, but i no longer trust my memory.

>Bill Tait
>FOM mailing list
>FOM at cs.nyu.edu

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