{ "id": "2401.13859", "version": "v1", "published": "2024-01-24T23:51:00.000Z", "updated": "2024-01-24T23:51:00.000Z", "title": "Proving the 5-Engel identity in the 2-generator group of exponent four", "authors": [ "Colin Ramsay" ], "categories": [ "math.CO", "math.GR" ], "abstract": "It is known that the fifth Engel word $E_5$ is trivial in the 2-generator group of exponent four $B(2,4)$, and so can be written as a product of fourth powers. Explicit products of 250 and 28 powers are known, using fourth powers of words up to lengths four and ten respectively. Using a reduction technique based on the recursive enumerability of the set of trivial words in a finite presentation we were able to rewrite $E_5$ as a product of 26 fourth powers of words up to length five.", "revisions": [ { "version": "v1", "updated": "2024-01-24T23:51:00.000Z" } ], "analyses": { "keywords": [ "fourth powers", "fifth engel word", "finite presentation", "reduction technique", "trivial words" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }