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arXiv · 1904.07004

All $(\infty,1)$-toposes have strict univalent universes

Michael Shulman
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Abstract

We prove the conjecture that any Grothendieck $(\infty,1)$-topos can be presented by a Quillen model category that interprets homotopy type theory with strict univalent universes. Thus, homotopy type theory can be used as a formal language for reasoning internally to $(\infty,1)$-toposes, just as higher-order logic is used for 1-toposes. As part of the proof, we give a new, more explicit, characterization of the fibrations in injective model structures on presheaf categories. In particular, we show that they generalize the coflexible algebras of 2-monad theory.

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Michael Shulman. 2019-04-15. All $(\infty,1)$-toposes have strict univalent universes. https://arxiv.org/abs/1904.07004

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