Largest family without A union B contained in C intersect D

2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/98641Let F be a family of subsets of an n-element set not containing four distinct members such that A union B is contained in C intersect D. It is proved that the maximum size of F under this condition is equal to the sum of the two largest binomial coefficients of order n. The maximum families are also characterized. A LYM-type inequality for such families is given, too.6 pagesCombinatorics05D05Largest family without A union B contained in C intersect Dtext