{ "id": "1205.1170", "version": "v1", "published": "2012-05-06T01:32:07.000Z", "updated": "2012-05-06T01:32:07.000Z", "title": "A De Bruijn-Erdos theorem for 1-2 metric spaces", "authors": [ "Vasek Chvatal" ], "categories": [ "math.CO" ], "abstract": "A special case of a combinatorial theorem of De Bruijn and Erdos asserts that every noncollinear set of n points in the plane determines at least n distinct lines. Chen and Chvatal suggested a possible generalization of this assertion in metric spaces with appropriately defined lines. We prove this generalization in all metric spaces where each nonzero distance equals 1 or 2.", "revisions": [ { "version": "v1", "updated": "2012-05-06T01:32:07.000Z" } ], "analyses": { "subjects": [ "05D99", "51G99" ], "keywords": [ "metric spaces", "bruijn-erdos theorem", "nonzero distance equals", "erdos asserts", "special case" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1205.1170C" } } }