Dane publikacji
Tom 68
Zeszyt 2
Czasopismo: Bulletin of the Polish Academy of Sciences Mathematics
Strony: 105-115
Data publikacji online: 31.01.2021
Liczba wyświetleń: 0
Liczba pobrań: 0
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Abstrakt
We establish that the statement “For every infinite set $X$, every almost disjoint family in $X$ can be extended to a maximal almost disjoint (MAD) family in $X$” is not provable in $\mathsf {ZF}$ + Boolean prime ideal theorem + Axiom of Countable Choice.
This settles an open problem from Tachtsis [On the existence of almost disjoint and MAD families without $\mathsf {AC}$, Bull. Polish Acad. Sci. Math. 67 (2019), 101–124].