Notes

Description:

In Rav [1977], it is shown that under the assumption of \(RL\) (Form 99) and certain conditions on a set \(X\) and filter \(\cal F\) in \({\cal P}(X)\), \({\cal F}\) can be extended to an ultrafilter.

Content:

In Rav [1977], it is shown that under the assumption of \(RL\) (Form 99) and certain conditions on a set \(X\) and filter \(\cal F\) in \({\cal P}(X)\), \({\cal F}\) can be extended to an ultrafilter. Either of the following conditions suffices:

  1. \(\{A : A\subseteq \cal P(X)\wedge A\) finite \(\wedge\forall x,y\in  A (x \neq  y \rightarrow  x \cap  y = \emptyset ) \}\)has a choice function.
  2. \(\cal F\) has a choice function.

Howard-Rubin number: 78

Type: Summary of results

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