Intersecting families in (l[m]) ∨ (k[n])

被引:0
作者
Wang, Jun [1 ]
Zhang, Huajun [2 ]
机构
[1] Shanghai Normal Univ, Dept Math, Shanghai 200234, Peoples R China
[2] Zhejiang Normal Univ, Dept Math, Jinhua 321004, Zhejiang, Peoples R China
基金
中国国家自然科学基金;
关键词
Family of sets; Intersecting family; Erdos-Ko-Rado theorem; KO-RADO THEOREM;
D O I
10.1007/s10878-020-00648-3
中图分类号
TP39 [计算机的应用];
学科分类号
081203 ; 0835 ;
摘要
Let m, n, l and k be positive integers with l not equal k, n > 2k, m < 2l and n = max{m, n} >= l + k. If F is an intersecting family in (([m])(l)) boolean OR (([n])(k)), then vertical bar F vertical bar <= max{((m)(l)), ((m - 1)(l -1)) + ((n - 1)(k - 1))}. Unless n = l + k >= m, equality holds if and only if ((m-1)(l)) >= ((n - 1)(k - 1)) and F = (([m])(l)) or ((m-1)(l)) <= ((n - 1)(k - 1)) and F consists of all members of (([m])(l)) boolean OR (([n])(k)) that contain a fixed element of [m] boolean AND [n].
引用
收藏
页码:1020 / 1029
页数:10
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