{"department":[{"_id":"DaAl"}],"article_processing_charge":"No","type":"conference","_id":"6676","status":"public","quality_controlled":"1","publication_status":"published","related_material":{"record":[{"id":"14364","status":"public","relation":"later_version"}]},"citation":{"ama":"Alistarh D-A, Aspnes J, Ellen F, Gelashvili R, Zhu L. Why extension-based proofs fail. In: <i>Proceedings of the 51st Annual ACM SIGACT Symposium on Theory of Computing</i>. ACM Press; 2019:986-996. doi:<a href=\"https://doi.org/10.1145/3313276.3316407\">10.1145/3313276.3316407</a>","chicago":"Alistarh, Dan-Adrian, James Aspnes, Faith Ellen, Rati Gelashvili, and Leqi Zhu. “Why Extension-Based Proofs Fail.” In <i>Proceedings of the 51st Annual ACM SIGACT Symposium on Theory of Computing</i>, 986–96. ACM Press, 2019. <a href=\"https://doi.org/10.1145/3313276.3316407\">https://doi.org/10.1145/3313276.3316407</a>.","mla":"Alistarh, Dan-Adrian, et al. “Why Extension-Based Proofs Fail.” <i>Proceedings of the 51st Annual ACM SIGACT Symposium on Theory of Computing</i>, ACM Press, 2019, pp. 986–96, doi:<a href=\"https://doi.org/10.1145/3313276.3316407\">10.1145/3313276.3316407</a>.","apa":"Alistarh, D.-A., Aspnes, J., Ellen, F., Gelashvili, R., &#38; Zhu, L. (2019). Why extension-based proofs fail. In <i>Proceedings of the 51st Annual ACM SIGACT Symposium on Theory of Computing</i> (pp. 986–996). Phoenix, AZ, United States: ACM Press. <a href=\"https://doi.org/10.1145/3313276.3316407\">https://doi.org/10.1145/3313276.3316407</a>","ieee":"D.-A. Alistarh, J. Aspnes, F. Ellen, R. Gelashvili, and L. Zhu, “Why extension-based proofs fail,” in <i>Proceedings of the 51st Annual ACM SIGACT Symposium on Theory of Computing</i>, Phoenix, AZ, United States, 2019, pp. 986–996.","ista":"Alistarh D-A, Aspnes J, Ellen F, Gelashvili R, Zhu L. 2019. Why extension-based proofs fail. Proceedings of the 51st Annual ACM SIGACT Symposium on Theory of Computing. STOC: Symposium on Theory of Computing, 986–996.","short":"D.-A. Alistarh, J. Aspnes, F. Ellen, R. Gelashvili, L. Zhu, in:, Proceedings of the 51st Annual ACM SIGACT Symposium on Theory of Computing, ACM Press, 2019, pp. 986–996."},"month":"06","author":[{"full_name":"Alistarh, Dan-Adrian","orcid":"0000-0003-3650-940X","id":"4A899BFC-F248-11E8-B48F-1D18A9856A87","last_name":"Alistarh","first_name":"Dan-Adrian"},{"full_name":"Aspnes, James","last_name":"Aspnes","first_name":"James"},{"first_name":"Faith","last_name":"Ellen","full_name":"Ellen, Faith"},{"full_name":"Gelashvili, Rati","last_name":"Gelashvili","first_name":"Rati"},{"full_name":"Zhu, Leqi","first_name":"Leqi","last_name":"Zhu"}],"date_published":"2019-06-01T00:00:00Z","title":"Why extension-based proofs fail","scopus_import":"1","date_created":"2019-07-24T09:13:05Z","conference":{"end_date":"2019-06-26","start_date":"2019-06-23","location":"Phoenix, AZ, United States","name":"STOC: Symposium on Theory of Computing"},"doi":"10.1145/3313276.3316407","publication":"Proceedings of the 51st Annual ACM SIGACT Symposium on Theory of Computing","language":[{"iso":"eng"}],"year":"2019","date_updated":"2023-12-13T12:28:28Z","day":"01","publication_identifier":{"isbn":["9781450367059"]},"main_file_link":[{"url":"https://arxiv.org/abs/1811.01421","open_access":"1"}],"publisher":"ACM Press","abstract":[{"lang":"eng","text":"It is impossible to deterministically solve wait-free consensus in an asynchronous system. The classic proof uses a valency argument, which constructs an infinite execution by repeatedly extending a finite execution. We introduce extension-based proofs, a class of impossibility proofs that are modelled as an interaction between a prover and a protocol and that include valency arguments.\r\n\r\nUsing proofs based on combinatorial topology, it has been shown that it is impossible to deterministically solve k-set agreement among n > k ≥ 2 processes in a wait-free manner. However, it was unknown whether proofs based on simpler techniques were possible. We show that this impossibility result cannot be obtained by an extension-based proof and, hence, extension-based proofs are limited in power."}],"user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","oa":1,"external_id":{"arxiv":["1811.01421"],"isi":["000523199100089"]},"page":"986-996","oa_version":"Preprint","isi":1}