Duality is a central concept in the theory of session types. Since a flaw was found in the original definition of duality for recursive types, several other definitions have been published. As their connection is not obvious, we compare the competing definitions, discuss tradeoffs, and prove some equivalences. Some of the results are mechanized in Agda.

中文翻译：

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会话类型的双重性：最终剪辑

二元性是会话类型理论的核心概念。由于在递归类型的对偶性的原始定义中发现了一个缺陷，因此已经发布了其他几个定义。由于它们的联系并不明显，我们比较了相互竞争的定义，讨论了权衡，并证明了一些等价性。部分结果在 Agda 中机械化。