{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,7,30]],"date-time":"2025-07-30T15:40:03Z","timestamp":1753890003712,"version":"3.41.2"},"reference-count":0,"publisher":"Centre pour la Communication Scientifique Directe (CCSD)","license":[{"start":{"date-parts":[[2019,3,29]],"date-time":"2019-03-29T00:00:00Z","timestamp":1553817600000},"content-version":"am","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2019,3,29]],"date-time":"2019-03-29T00:00:00Z","timestamp":1553817600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2019,3,29]],"date-time":"2019-03-29T00:00:00Z","timestamp":1553817600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2025,3,31]]},"abstract":"<jats:p>Normal-form bisimilarity is a simple, easy-to-use behavioral equivalence that relates terms in $\\lambda$-calculi by decomposing their normal forms into bisimilar subterms. Moreover, it typically allows for powerful up-to techniques, such as bisimulation up to context, which simplify bisimulation proofs even further. However, proving soundness of these relations becomes complicated in the presence of $\\eta$-expansion and usually relies on ad hoc proof methods which depend on the language. In this paper we propose a more systematic proof method to show that an extensional normal-form bisimilarity along with its corresponding up to context technique are sound. We illustrate our technique with three calculi: the call-by-value $\\lambda$-calculus, the call-by-value $\\lambda$-calculus with the delimited-control operators shift and reset, and the call-by-value $\\lambda$-calculus with the abortive control operators call\/cc and abort. In the first two cases, there was previously no sound up to context technique validating the $\\eta$-law, whereas no theory of normal-form bisimulations for a calculus with call\/cc and abort has been presented before. Our results have been fully formalized in the Coq proof assistant.<\/jats:p>","DOI":"10.23638\/lmcs-15(1:31)2019","type":"journal-article","created":{"date-parts":[[2025,4,3]],"date-time":"2025-04-03T17:35:01Z","timestamp":1743701701000},"source":"Crossref","is-referenced-by-count":0,"title":["Proving Soundness of Extensional Normal-Form Bisimilarities"],"prefix":"10.23638","volume":"Volume 15, Issue 1","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1477-4635","authenticated-orcid":false,"given":"Dariusz","family":"Biernacki","sequence":"first","affiliation":[]},{"given":"Serguei","family":"Lenglet","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7012-4346","authenticated-orcid":false,"given":"Piotr","family":"Polesiuk","sequence":"additional","affiliation":[]}],"member":"25203","published-online":{"date-parts":[[2019,3,29]]},"container-title":["Logical Methods in Computer Science"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/arxiv.org\/pdf\/1711.00113v4","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/arxiv.org\/pdf\/1711.00113v4","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,4,3]],"date-time":"2025-04-03T17:35:01Z","timestamp":1743701701000},"score":1,"resource":{"primary":{"URL":"http:\/\/lmcs.episciences.org\/4041"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,3,29]]},"references-count":0,"URL":"https:\/\/doi.org\/10.23638\/lmcs-15(1:31)2019","relation":{"has-preprint":[{"id-type":"arxiv","id":"1711.00113v2","asserted-by":"subject"},{"id-type":"arxiv","id":"1711.00113v1","asserted-by":"subject"}],"is-same-as":[{"id-type":"arxiv","id":"1711.00113","asserted-by":"subject"},{"id-type":"doi","id":"10.48550\/arXiv.1711.00113","asserted-by":"subject"}]},"ISSN":["1860-5974"],"issn-type":[{"type":"electronic","value":"1860-5974"}],"subject":[],"published":{"date-parts":[[2019,3,29]]},"article-number":"4041"}}