Largest family without A union B contained in C intersect D
组合数学
2007-05-23 v1
摘要
Let 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.
引用
@article{arxiv.math/0407373,
title = {Largest family without A union B contained in C intersect D},
author = {Annalisa De Bonis and Gyula O. H. Katona and Konrad J. Swanepoel},
journal= {arXiv preprint arXiv:math/0407373},
year = {2007}
}
备注
6 pages