{ "id": "math/0301085", "version": "v7", "published": "2003-01-09T15:28:35.000Z", "updated": "2010-10-31T19:04:55.000Z", "title": "The Hurewicz covering property and slaloms in the Baire space", "authors": [ "Boaz Tsaban" ], "comment": "Small updates", "journal": "Fundamenta Mathematicae 181 (2004), 273--280", "doi": "10.4064/fm181-3-5", "categories": [ "math.GN", "math.CO", "math.LO" ], "abstract": "According to a result of Kocinac and Scheepers, the Hurewicz covering property is equivalent to a somewhat simpler selection property: For each sequence of large open covers of the space one can choose finitely many elements from each cover to obtain a groupable cover of the space. We simplify the characterization further by omitting the need to consider sequences of covers: A set of reals $X$ satisfies the Hurewicz property if, and only if, each large open cover of $X$ contains a groupable subcover. This solves in the affirmative a problem of Scheepers. The proof uses a rigorously justified abuse of notation and a \"structure\" counterpart of a combinatorial characterization, in terms of slaloms, of the minimal cardinality b of an unbounded family of functions in the Baire space. In particular, we obtain a new characterization of $\\b$.", "revisions": [ { "version": "v7", "updated": "2010-10-31T19:04:55.000Z" } ], "analyses": { "subjects": [ "37F20", "26A03", "03E75" ], "keywords": [ "hurewicz covering property", "baire space", "large open cover", "somewhat simpler selection property", "characterization" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2003math......1085T" } } }