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arXiv · 2606.13210

On a local variant of the 12th Delfino problem -- the $Π$-side

Stefan Hoffelner
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Abstract

Assume that \(M_n\), the canonical inner model with \(n\) Woodin cardinals, exists. We force a model with continuum \(\aleph_2\) in which every \(\boldsymbolΣ^1_{n+2}\) set of reals is Lebesgue measurable and has the Baire property, the \(Σ^1_{n+2}\)- and \(Π^1_{n+3}\)-uniformization properties hold, and the reals admit a \(Δ^1_{n+3}\)-definable well-order. Thus regularity up to a fixed finite projective level, together with a definable well-order of the reals at the adjacent level, does not force the determinacy strength which would normally explain that regularity, even when this package is strengthened by adjacent \(Σ\)- and \(Π\)-uniformization. In particular, this gives a negative answer to a local form of Woodin's twelfth Delfino problem asked by Friedman-Schindler.

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Stefan Hoffelner. 2026-06-11. On a local variant of the 12th Delfino problem -- the $Π$-side. https://arxiv.org/abs/2606.13210

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