{"month":"06","publication_status":"published","oa_version":"Preprint","scopus_import":"1","language":[{"iso":"eng"}],"publication_identifier":{"isbn":["9781450367059"]},"year":"2019","conference":{"end_date":"2019-06-26","location":"Phoenix, AZ, United States","start_date":"2019-06-23","name":"STOC: Symposium on Theory of Computing"},"date_created":"2019-07-24T09:13:05Z","date_updated":"2023-12-13T12:28:28Z","department":[{"_id":"DaAl"}],"author":[{"orcid":"0000-0003-3650-940X","id":"4A899BFC-F248-11E8-B48F-1D18A9856A87","full_name":"Alistarh, Dan-Adrian","last_name":"Alistarh","first_name":"Dan-Adrian"},{"first_name":"James","last_name":"Aspnes","full_name":"Aspnes, James"},{"first_name":"Faith","full_name":"Ellen, Faith","last_name":"Ellen"},{"last_name":"Gelashvili","full_name":"Gelashvili, Rati","first_name":"Rati"},{"last_name":"Zhu","full_name":"Zhu, Leqi","first_name":"Leqi"}],"publication":"Proceedings of the 51st Annual ACM SIGACT Symposium on Theory of Computing","page":"986-996","_id":"6676","status":"public","citation":{"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.","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>.","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.","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>.","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.","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>"},"doi":"10.1145/3313276.3316407","article_processing_charge":"No","date_published":"2019-06-01T00:00:00Z","external_id":{"isi":["000523199100089"],"arxiv":["1811.01421"]},"quality_controlled":"1","oa":1,"title":"Why extension-based proofs fail","related_material":{"record":[{"status":"public","id":"14364","relation":"later_version"}]},"type":"conference","user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","publisher":"ACM Press","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1811.01421"}],"day":"01","isi":1,"abstract":[{"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.","lang":"eng"}]}