Cofinality of the nonstationary ideal

Pierre Matet; Andrzej Rosłanowski; Saharon Shelah

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Cofinality of the nonstationary ideal

Pierre Matet·Andrzej Rosłanowski·Saharon Shelah

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Abstract

We show that the reduced cofinality of the nonstationary ideal NS_kappa on a regular uncountable cardinal kappa may be less than its cofinality, where the reduced cofinality of NS_kappa is the least cardinality of any family F of nonstationary subsets of kappa such that every nonstationary subset of kappa can be covered by less than $\kappa$ many members of F.

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BibTeX RIS

Pierre Matet, Andrzej Rosłanowski, Saharon Shelah. 2002-10-06. Cofinality of the nonstationary ideal. https://arxiv.org/abs/math/0210087

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