{ "id": "1709.00313", "version": "v1", "published": "2017-09-01T13:53:49.000Z", "updated": "2017-09-01T13:53:49.000Z", "title": "A Simple Proof Characterizing Interval Orders with Interval Lengths between 1 and $k$", "authors": [ "Simona Boyadzhiyska", "Garth Isaak", "Ann Trenk" ], "comment": "9 pages, 1 figure", "categories": [ "math.CO" ], "abstract": "A poset $P= (X, \\prec)$ has an interval representation if each $x \\in X$ can be assigned a real interval $I_x$ so that $x \\prec y$ in $P$ if and only if $I_x$ lies completely to the left of $I_y$. Such orders are called \\emph{interval orders}. Fishburn proved that for any positive integer $k$, an interval order has a representation in which all interval lengths are between $1$ and $k$ if and only if the order does not contain $\\mathbf{(k+2)+1}$ as an induced poset. In this paper, we give a simple proof of this result using a digraph model.", "revisions": [ { "version": "v1", "updated": "2017-09-01T13:53:49.000Z" } ], "analyses": { "subjects": [ "06A99", "05C62" ], "keywords": [ "simple proof characterizing interval orders", "interval lengths", "digraph model", "real interval", "interval representation" ], "note": { "typesetting": "TeX", "pages": 9, "language": "en", "license": "arXiv", "status": "editable" } } }