{ "id": "1310.4533", "version": "v1", "published": "2013-10-16T22:08:00.000Z", "updated": "2013-10-16T22:08:00.000Z", "title": "Ultrafilter extensions of linear orders", "authors": [ "Denis I. Saveliev" ], "categories": [ "math.LO" ], "abstract": "It was recently shown that arbitrary first-order models canonically extend to models (of the same language) consisting of ultrafilters. The main precursor of this construction was the extension of semigroups to semigroups of ultrafilters, a technique allowing to obtain significant results in algebra and dynamics. Here we consider another particular case where the models are linearly ordered sets. We explicitly calculate the extensions of a given linear order and the corresponding operations of minimum and maximum on a set. We show that the extended relation is not more an order however is close to the natural linear ordering of nonempty half-cuts of the set and that the two extended operations define a skew lattice structure on the set of ultrafilters.", "revisions": [ { "version": "v1", "updated": "2013-10-16T22:08:00.000Z" } ], "analyses": { "subjects": [ "06A05", "03C55", "06B75", "54D80" ], "keywords": [ "linear order", "ultrafilter extensions", "arbitrary first-order models canonically extend", "skew lattice structure", "semigroups" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1310.4533S" } } }