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arXiv · 2408.10182

The breadth of constructibility degrees and definable Sierpi\'nski's coverings

Alessandro Andretta·Lorenzo Notaro
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Abstract

Generalizing a result of T\"ornquist and Weiss, we study the connection between the existence of $\varSigma_2^1$ Sierpi\'{n}ski's coverings of $\mathbb{R}^n$, and a cardinal invariant of the upper semi-lattice of constructibility degrees known as breadth.

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Alessandro Andretta, Lorenzo Notaro. 2024-08-19. The breadth of constructibility degrees and definable Sierpi\'nski's coverings. https://doi.org/10.4064/fm240819-27-11

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