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arXiv · 1811.01421

Why Extension-Based Proofs Fail

Dan Alistarh·James Aspnes·Faith Ellen·Rati Gelashvili·Leqi Zhu
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Abstract

We introduce extension-based proofs, a class of impossibility proofs that includes valency arguments. They are modelled as an interaction between a prover and a protocol. Using proofs based on combinatorial topology, it has been shown that it is impossible to deterministically solve k-set agreement among n > k > 1 processes in a wait-free manner in certain asynchronous models. However, it was unknown whether proofs based on simpler techniques were possible. We show that this impossibility result cannot be obtained for one of these models by an extension-based proof and, hence, extension-based proofs are limited in power.

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Dan Alistarh, James Aspnes, Faith Ellen, Rati Gelashvili, Leqi Zhu. 2018-11-04. Why Extension-Based Proofs Fail. https://arxiv.org/abs/1811.01421

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