Description:

Form 385 implies Form 70

Content:

We give a proof that Form 385 (Every proper filter with a countable base over a set \(S\) (in \({\cal P}(S)\)) can be extended to an ultrafilter) implies Form 70 (There is a non-trivial ultrafilter on \(\omega\).) It is sufficient to show that there is a filter on \(\omega\) with a countable base. For each \(n\in\omega\) let \(x_{n} = \{m\in\omega: m\geq n\}\). Then, \(X = \{x_n: n\in\omega\}\) is a countable set which is a base for a filter \(\cal F\) on \(\omega\).

Howard-Rubin number: 150

Type: Proof

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