Let n, s1, s2,..., sn be non-negative integers and M(s1, s2,...,sn) ={(a1, a2,..., a.)| ai is an integer and 0≤ai ≤si for each i}. In this paper, the cardinality of maximum trees of finite sequences in M(s1, s2,...,...Let n, s1, s2,..., sn be non-negative integers and M(s1, s2,...,sn) ={(a1, a2,..., a.)| ai is an integer and 0≤ai ≤si for each i}. In this paper, the cardinality of maximum trees of finite sequences in M(s1, s2,..., sn) sn) is obtained, which generalizes some of Frankl's results on families of finite sets with prescribed cardinalities for pairwise intersections.展开更多
文摘Let n, s1, s2,..., sn be non-negative integers and M(s1, s2,...,sn) ={(a1, a2,..., a.)| ai is an integer and 0≤ai ≤si for each i}. In this paper, the cardinality of maximum trees of finite sequences in M(s1, s2,..., sn) sn) is obtained, which generalizes some of Frankl's results on families of finite sets with prescribed cardinalities for pairwise intersections.