Fragments of Martin's axiom

Yinhe Peng

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arXiv · 2510.21496

Fragments of Martin's axiom

Yinhe Peng

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Abstract

We show that Martin's axiom for $\omega_1$ dense sets is equivalent to its fragment asserting that every ccc poset has the Knaster property K$_3$. On the other hand, we show that the dimension 3 in K$_3$ is in some sense minimal.

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BibTeX RIS

Yinhe Peng. 2025-10-24. Fragments of Martin's axiom. https://arxiv.org/abs/2510.21496

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