{ "id": "1412.0195", "version": "v1", "published": "2014-11-30T08:33:25.000Z", "updated": "2014-11-30T08:33:25.000Z", "title": "On countable cofinality and decomposition of definable thin orderings", "authors": [ "Vladimir Kanovei", "Vassily Lyubetsky" ], "comment": "arXiv admin note: substantial text overlap with arXiv:1408.1202", "categories": [ "math.LO" ], "abstract": "We prove that in some cases definable thin sets (including chains) of Borel partial orderings are necessarily countably cofinal. This includes the following cases: analytic thin sets, ROD thin sets in the Solovay model, and $\\Sigma^1_2$ thin sets in the assumption that $\\omega_1^{L[x]}<\\omega_1$ for all reals $x$. We also prove that definable thin wellorderings admit partitions into definable chains in the Solovay model.", "revisions": [ { "version": "v1", "updated": "2014-11-30T08:33:25.000Z" } ], "analyses": { "subjects": [ "03E15", "03E04", "03E40" ], "keywords": [ "definable thin orderings", "countable cofinality", "decomposition", "solovay model", "definable thin wellorderings admit partitions" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1412.0195K" } } }