{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,7,30]],"date-time":"2025-07-30T16:43:45Z","timestamp":1753893825720,"version":"3.41.2"},"reference-count":0,"publisher":"The Electronic Journal of Combinatorics","issue":"4","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Electron. J. Combin."],"abstract":"<jats:p>We show that every generator, in a certain set of generators for the variety of\u00a0reflexive near unanimity graphs, admits a semilattice polymorphism. We then find a retract of a product of such graphs (paths, in fact) that has no semilattice polymorphism. This verifies for reflexive graphs\u00a0that the variety of graphs with semilattice polymorpisms does not contain the variety of graphs with near-unanimity, or even $3$-ary near-unanimity\u00a0polymorphisms.<\/jats:p>","DOI":"10.37236\/6196","type":"journal-article","created":{"date-parts":[[2020,1,10]],"date-time":"2020-01-10T15:09:48Z","timestamp":1578668988000},"source":"Crossref","is-referenced-by-count":0,"title":["Reflexive Graphs with Near Unanimity but no Semilattice Polymorphisms"],"prefix":"10.37236","volume":"25","author":[{"given":"Mark","family":"Siggers","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"23455","published-online":{"date-parts":[[2018,10,5]]},"container-title":["The Electronic Journal of Combinatorics"],"original-title":[],"link":[{"URL":"https:\/\/www.combinatorics.org\/ojs\/index.php\/eljc\/article\/download\/v25i4p2\/pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.combinatorics.org\/ojs\/index.php\/eljc\/article\/download\/v25i4p2\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2020,1,17]],"date-time":"2020-01-17T04:25:55Z","timestamp":1579235155000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.combinatorics.org\/ojs\/index.php\/eljc\/article\/view\/v25i4p2"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,10,5]]},"references-count":0,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2018,10,5]]}},"URL":"https:\/\/doi.org\/10.37236\/6196","relation":{},"ISSN":["1077-8926"],"issn-type":[{"type":"electronic","value":"1077-8926"}],"subject":[],"published":{"date-parts":[[2018,10,5]]},"article-number":"P4.2"}}