一句话:通过多项式单子与 opetopic 类型,在类型论内部定义 ∞-群胚,并证明其与类型宇宙等价。
本文研究如何在类型论内部以完全一致的方式编码 ∞-群胚等高等代数结构。作者扩展类型论,引入一个由定义性结合且含单位的 polynomial monads 构成的宇宙,并由此给出 opetopic type 的定义,使其能够编码多种完全一致的代数结构。基于这一框架,作者在类型论内部定义了 ∞-群胚,并证明该 ∞-群胚的类型与类型宇宙等价。这意味着每个类型都在内部承认 ∞-群胚结构,并且这种结构是唯一的,从而建立了类型与内部 ∞-群胚之间的精确对应。
By extending type theory with a universe of definitionally associative and unital polynomial monads, we show how to arrive at a definition of opetopic type which is able to encode a number of fully coherent algebraic structures. In particular, our approach leads to a definition of ∞-groupoid internal to type theory and we prove that the type of such ∞-groupoids is equivalent to the universe of types. That is, every type admits the structure of an ∞-groupoid internally, and this structure is unique.