{ "id": "math/9912056", "version": "v4", "published": "1999-12-07T22:48:38.000Z", "updated": "2000-01-28T02:28:32.000Z", "title": "A combinatorial characterization of second category subsets of X^ω", "authors": [ "Apoloniusz Tyszka" ], "comment": "with a counterexample by T. Bartoszynski, to appear in J. Nat. Geom", "journal": "Journal of Natural Geometry 18 (2000), pp.125-130", "categories": [ "math.LO", "math-ph", "math.GN", "math.MP" ], "abstract": "Let a finite non-empty X is equipped with discrete topology. We prove that S \\subseteq X^\\omega is of second category if and only if for each f:\\omega -> \\bigcup_{n \\in \\omega} X^n there exists a sequence {a_n}_{n \\in \\omega} belonging to S such that for infinitely many i \\in \\omega the infinite sequence {a_{i+n}}_{n \\in \\omega} extends the finite sequence f(i).", "revisions": [ { "version": "v4", "updated": "2000-01-28T02:28:32.000Z" } ], "analyses": { "subjects": [ "03E05", "54E52" ], "keywords": [ "second category subsets", "combinatorial characterization", "infinite sequence", "discrete topology" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "1999math.....12056T" } } }