arXiv math/93112061993-11-15math.LO

Ultrafilters on omega

James E. Baumgartner

英文摘要：

A variety of classes of naturally arising ultrafilters on omega is discussed, and the question is raised whether it is consistent that the classes are empty. Since all the classes contain the P-point ultrafilters, a negative answer would greatly extend the famous theorem of Shelah.

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