- #1
nomadreid
Gold Member
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I came across some old notes that seem to be dubious, with no references. So please correct:
The notes say that if Ramsey cardinals exist, and the constructible universe L is regarded as a set, and PDef(.) is taking the constructible power set (i.e., subsets are formed using Def), then
(VRamsey card,∈) |= PDef(L) is countable & PDef(PDef(L)) is uncountable.
Thanks for corrections or comments.
The notes say that if Ramsey cardinals exist, and the constructible universe L is regarded as a set, and PDef(.) is taking the constructible power set (i.e., subsets are formed using Def), then
(VRamsey card,∈) |= PDef(L) is countable & PDef(PDef(L)) is uncountable.
Thanks for corrections or comments.