arXiv · 2106.13053
Answering in negative a question of M. Hru\v{s}\'ak, we construct a Borel ideal not extendable to any $F_\sigma$ ideal and such that it is not Kat\v{e}tov above the ideal $\mathrm{conv}$.
Adam Kwela. 2021-06-24. On extendability to $F_\sigma$ ideals. https://arxiv.org/abs/2106.13053
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