局部可解任务与配价论证的局限性
Locally Solvable Tasks and the Limitations of Valency Arguments
摘要：
在著名的FLP一致不可能性证明中，提出了一种在分布式计算中证明不可能性结果的策略。该策略本质上是局部的，因为在每个阶段，考虑用于共识的假设协议的一种配置，以及可能的扩展的未来价。这种证明策略已经在许多与共识相关的情况下使用，这让人想知道为什么它没有被用于另外两个众所周知的任务：集合一致性和重命名的不可能结果。本文提供了一个解释，为什么这些任务的不可能性证明一直是一个全球性的。它表明，在以下意义上，协议总是可以在本地解决这样的任务。给定一个配置和它所有的未来价，如果选择了一个后继配置，那么协议可以揭示这个执行分支中的所有决策，满足任务规范。这一结果显示为集协议和重命名，这意味着这些任务没有本地不可能的证明。
英文摘要：
An elegant strategy for proving impossibility results in distributed computing was introduced in the celebrated FLP consensus impossibility proof. This strategy is local in nature as at each stage, one configuration of a hypothetical protocol for consensus is considered, together with future valencies of possible extensions. This proof strategy has been used in numerous situations related to consensus, leading one to wonder why it has not been used in impossibility results of two other well-known tasks: set agreement and renaming. This paper provides an explanation of why impossibility proofs of these tasks have been of a global nature. It shows that a protocol can always solve such tasks locally, in the following sense. Given a configuration and all its future valencies, if a single successor configuration is selected, then the protocol can reveal all decisions in this branch of executions, satisfying the task specification. This result is shown for both set agreement and renaming, implying that there are no local impossibility proofs for these tasks.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
