Journal of the European Mathematical Society ( IF 2.6 ) Pub Date : 2021-03-08 , DOI: 10.4171/jems/1050 Krzysztof Kapulkin 1 , Peter LeFanu Lumsdaine 2
To this end, we first give a general technique for constructing categorical models of dependent type theory, using universes to obtain coherence. We then construct a (weakly) universal Kan fibration, and use it to exhibit a model in simplicial sets. Lastly, we introduce the Univalence Axiom, in several equivalent formulations, and show that it holds in our model.
As a corollary, we conclude that Martin-Löf type theory with one univalent universe (formulated in terms of contextual categories) is at least as consistent as ZFC with two inaccessible cardinals.
中文翻译:
单价基础的简单模型(在Voevodsky之后)
我们在简单集类别中介绍Voevodsky的单价类型理论模型的构造。
为此,我们首先给出一种通用技术,用于构造依赖类型理论的分类模型,并使用宇宙获得连贯性。然后,我们构造一个(弱)通用Kan纤维,并使用它在简单集中展示一个模型。最后,我们以几种等效的方式介绍Univalence公理,并证明它在我们的模型中成立。
作为推论,我们得出结论,具有一个单价宇宙(根据上下文类别来表示)的Martin-Löf类型理论至少与具有两个不可访问的基数的ZFC一致。