FOM: Conway's surreal numbers

Vaughan R. Pratt pratt at cs.Stanford.EDU
Wed Nov 12 16:01:09 EST 1997


>Conway says in his book that "deep logical theorems show that
>one could not [get hyperreals] in such a simple way".  It's
>easy to see this--Conway's construction doesn't need AC.

Indeed, and I should have tempered what I said about Conway's system
having much stronger closure properties than formal power series with
the above caveat.

Vaughan



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