{ "id": "math/0212312", "version": "v6", "published": "2002-12-22T21:22:47.000Z", "updated": "2010-10-31T19:02:48.000Z", "title": "The combinatorics of splittability", "authors": [ "Boaz Tsaban" ], "comment": "Small updates", "journal": "Annals of Pure and Applied Logic 129 (2004), 107--130", "doi": "10.1016/j.apal.2003.03.001", "categories": [ "math.LO", "math.CA", "math.CO", "math.GN" ], "abstract": "Marion Scheepers, in his studies of the combinatorics of open covers, introduced the property Split(U,V) asserting that a cover of type U can be split into two covers of type V. In the first part of this paper we give an almost complete classification of all properties of this form where U and V are significant families of covers which appear in the literature (namely, large covers, omega-covers, tau-covers, and gamma-covers), using combinatorial characterizations of these properties in terms related to ultrafilters on N. In the second part of the paper we consider the questions whether, given U and V, the property Split(U,V) is preserved under taking finite unions, arbitrary subsets, powers or products. Several interesting problems remain open.", "revisions": [ { "version": "v6", "updated": "2010-10-31T19:02:48.000Z" } ], "analyses": { "subjects": [ "03E05", "54D20", "54D80" ], "keywords": [ "combinatorics", "property split", "splittability", "interesting problems remain open", "marion scheepers" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2002math.....12312T" } } }