{ "id": "2007.06058", "version": "v1", "published": "2020-07-12T18:25:11.000Z", "updated": "2020-07-12T18:25:11.000Z", "title": "Half-isomorphisms whose inverses are also half-isomorphisms", "authors": [ "Giliard Souza dos Anjos" ], "comment": "11 pages", "categories": [ "math.GR" ], "abstract": "Let $(G,*)$ and $(G',\\cdot)$ be groupoids. A bijection $f: G \\rightarrow G'$ is called a half-isomorphism if $f(x*y)\\in\\{f(x)\\cdot f(y),f(y)\\cdot f(x)\\}$, for any $ x, y \\in G$. A half-isomorphism of a groupoid onto itself is a half-automorphism. A half-isomorphism $f$ is called special if $f^{-1}$ is also a half-isomorphism. In this paper, necessary and sufficient conditions for the existence of special half-isomorphisms on groupoids and quasigroups are obtained. Furthermore, some examples of non-special half-automorphisms for loops of infinite order are provided.", "revisions": [ { "version": "v1", "updated": "2020-07-12T18:25:11.000Z" } ], "analyses": { "subjects": [ "20N02", "20N05" ], "keywords": [ "sufficient conditions", "special half-isomorphisms", "non-special half-automorphisms", "infinite order", "quasigroups" ], "note": { "typesetting": "TeX", "pages": 11, "language": "en", "license": "arXiv", "status": "editable" } } }