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arXiv · 1808.09056

On the existence of large antichains for definable quasi-orders

Benjamin D. Miller·Zoltán Vidnyánszky
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Abstract

We generalize Harrington-Marker-Shelah's Dilworth-style characterization of the existence of non-empty perfect antichains to co-analytic quasi-orders, establish the analogous theorem at the next definable cardinal, and consider generalizations beyond the first level of the projective hierarchy.

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Benjamin D. Miller, Zoltán Vidnyánszky. 2018-08-27. On the existence of large antichains for definable quasi-orders. https://arxiv.org/abs/1808.09056

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