{ "id": "2110.10445", "version": "v3", "published": "2021-10-20T09:20:25.000Z", "updated": "2022-03-25T02:41:18.000Z", "title": "Note on the Polyhedral Description of the Minkowski Sum of Two L-convex Sets", "authors": [ "Satoko Moriguchi", "Kazuo Murota" ], "comment": "36 pages", "categories": [ "math.CO" ], "abstract": "L-convex sets are one of the most fundamental concepts in discrete convex analysis. Furthermore, the Minkowski sum of two L-convex sets, called L2-convex sets, is an intriguing object that is closely related to polymatroid intersection. This paper reveals the polyhedral description of an L2-convex set, together with the observation that the convex hull of an L2-convex set is a box-TDI polyhedron. Two different proofs are given for the polyhedral description. The first is a structural short proof, relying on the conjugacy theorem in discrete convex analysis, and the second is a direct algebraic proof, based on Fourier-Motzkin elimination. The obtained results admit natural graph representations. Implications of the obtained results in discrete convex analysis are also discussed.", "revisions": [ { "version": "v3", "updated": "2022-03-25T02:41:18.000Z" } ], "analyses": { "subjects": [ "52A41", "90C27", "90C25" ], "keywords": [ "polyhedral description", "l-convex sets", "minkowski sum", "discrete convex analysis", "l2-convex set" ], "note": { "typesetting": "TeX", "pages": 36, "language": "en", "license": "arXiv", "status": "editable" } } }