{ "id": "2012.00476", "version": "v1", "published": "2020-12-01T13:29:33.000Z", "updated": "2020-12-01T13:29:33.000Z", "title": "Families of finite sets in which no set is covered by the union of the others", "authors": [ "Guillermo Alesandroni" ], "categories": [ "math.CO", "math.AC" ], "abstract": "Let F be a finite family of finite sets. We prove the following: (i) F satisfies the condition of the title if and only if for every pair of distinct subfamilies {A_1,...,A_r}, {B_1,...,B_s} of F, the union of the A_i is different from the union of the B_i. (ii) If F satisfies the condition of the title, then the number of subsets of the union of the members of F containing at least one set of F is odd. We give two applications of these results, one to number theory and one to commutative algebra.", "revisions": [ { "version": "v1", "updated": "2020-12-01T13:29:33.000Z" } ], "analyses": { "keywords": [ "finite sets", "number theory", "distinct subfamilies", "applications", "commutative algebra" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }