The Boolean prime ideal theorem does not imply the extension of almost disjoint families to MAD families
نویسندگان
چکیده
منابع مشابه
Mad families constructed from perfect almost disjoint families
We prove the consistency of b > א1 together with the existence of a Π11definable mad family, answering a question posed by Friedman and Zdomskyy in [7, Question 16]. For the proof we construct a mad family in L which is an א1-union of perfect a.d. sets, such that this union remains mad in the iterated Hechler extension. The construction also leads us to isolate a new cardinal invariant, the Bor...
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ژورنال
عنوان ژورنال: Bulletin of the Polish Academy of Sciences Mathematics
سال: 2020
ISSN: 0239-7269,1732-8985
DOI: 10.4064/ba201014-22-1