There may be simple $P_{\aleph _ 1}$- and $P_{\aleph _ 2}$-points and the Rudin-Keisler ordering may be downward directed

DOI10.1016/0168-0072(87)90082-0zbMath0634.03047OpenAlexW2144799232WikidataQ59410903 ScholiaQ59410903MaRDI QIDQ1096622

Publication date: 1987

Published in: Annals of Pure and Applied Logic (Search for Journal in Brave)

Full work available at URL: https://doi.org/10.1016/0168-0072(87)90082-0

zbMATH Keywords

consistency ZFC iterated forcing P-point non-principal ultrafilters

Mathematics Subject Classification ID

Consistency and independence results (03E35)

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There may be simple \(P_{\aleph _ 1}\)- and \(P_{\aleph _ 2}\)-points and the Rudin-Keisler ordering may be downward directed