Jech's Notion
There is also a notion of stationary subset of, for a cardinal and a set such that, where is the set of subsets of of cardinality : . This notion is due to Thomas Jech. As before, is stationary if and only if it meets every club, where a club subset of is a set unbounded under and closed under union of chains of length at most . These notions are in general different, although for and they coincide in the sense that is stationary if and only if is stationary in .
The appropriate version of Fodor's lemma also holds for this notion.
Read more about this topic: Stationary Set
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