{ "id": "1907.13360", "version": "v1", "published": "2019-07-31T08:26:39.000Z", "updated": "2019-07-31T08:26:39.000Z", "title": "Complexity in Young's Lattice", "authors": [ "Alexander Wires" ], "comment": "13 pages", "categories": [ "math.CO", "math.LO" ], "abstract": "We investigate the complexity of the partial order relation of Young's lattice. The definable relations are characterized by establishing the maximal definability property modulo the single automorphism given by conjugation; consequently, as an ordered set Young's lattice has an undecidable elementary theory and is inherently non-finitely axiomatizable but every ideal generates a finitely axiomatizable universal class of equivalence relations. We end with conjectures concerning the complexities of the $\\Sigma_1$ and $\\Sigma_2$-theories.", "revisions": [ { "version": "v1", "updated": "2019-07-31T08:26:39.000Z" } ], "analyses": { "subjects": [ "05A05", "05A17", "05A18" ], "keywords": [ "complexity", "maximal definability property modulo", "partial order relation", "ordered set youngs lattice", "equivalence relations" ], "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable" } } }