{ "id": "1211.7110", "version": "v1", "published": "2012-11-29T22:38:57.000Z", "updated": "2012-11-29T22:38:57.000Z", "title": "Algorithms for discovering and proving theorems about permutation patterns", "authors": [ "Hjalti Magnusson", "Henning Ulfarsson" ], "comment": "13 pages, 3 figures", "categories": [ "math.CO", "cs.DM", "cs.DS", "cs.MS" ], "abstract": "We present an algorithm, called BiSC, that describes the patterns avoided by a given set of permutations. It automatically conjectures the statements of known theorems such as the descriptions of stack-sortable (Knuth 1975) and West-2-stack-sortable permutations (West 1990), smooth (Lakshmibai and Sandhya 1990) and forest-like permutations (Bousquet-Melou and Butler 2007), and simsun permutations (Branden and Claesson 2011). The algorithm has also been used to discover new theorems and conjectures related to Young tableaux, Wilf-equivalences and sorting devices. We further give algorithms to prove a complete description of preimages of pattern classes under certain sorting devices. These generalize an algorithm of Claesson and Ulfarsson (2012) and allow us to prove a linear time algorithm for finding occurrences of the pattern 4312.", "revisions": [ { "version": "v1", "updated": "2012-11-29T22:38:57.000Z" } ], "analyses": { "subjects": [ "05A05" ], "keywords": [ "permutation patterns", "proving theorems", "sorting devices", "linear time algorithm", "discovering" ], "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1211.7110M" } } }