{ "id": "1004.5542", "version": "v2", "published": "2010-04-30T14:39:53.000Z", "updated": "2010-06-05T07:09:18.000Z", "title": "Linear ROD subsets of Borel partial orders are countably cofinal in the Solovay model", "authors": [ "Vladimir Kanovei" ], "comment": "5 pages", "categories": [ "math.LO" ], "abstract": "The following is true in the Solovay model. 1. If $\\le$ is a Borel partial order on a set $D$ of the reals, and $X$ is a ROD subset of $D$ linearly ordered by $\\le$, then the restriction of $\\le$ onto $X$ is countably cofinal. 2. If in addition every countable set $Y$ of $D$ has a strict upper bound in the sense of $\\le$ then the ordering $< D ; \\le >$ has no maximal chains that are ROD sets.", "revisions": [ { "version": "v2", "updated": "2010-06-05T07:09:18.000Z" } ], "analyses": { "subjects": [ "03E15" ], "keywords": [ "borel partial order", "linear rod subsets", "solovay model", "countably cofinal", "strict upper bound" ], "note": { "typesetting": "TeX", "pages": 5, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1004.5542K" } } }