Talk:Easton's theorem

1970: the theorem is from 1964
Writing 1970 after E's theorem is a bit misleading. The theorem is from 1964, it was the content of his Ph.D. thesis. It was published in 1970, in the first volume of the Annals of Math. Logic. (but it was fiarly available after 1964, many libraries still have the thesis) Kope (talk) 17:31, 4 February 2008 (UTC)

What formal system it is proved in?
In which formal systems Easton's theorem is provable?

Particularly, is it provable in NBG? in ZFC? ZF? VictorPorton (talk) 07:34, 18 August 2023 (UTC)
 * The Easton article claims (p. 141), that the proof is valid in Peano Arithmetic. VictorPorton (talk) 01:26, 20 August 2023 (UTC)