For all d≥3d≥3 we show that the cardinality of RR is at most ℵnℵn if and only if RdRd can be covered with (n+1)(d−1)+1(n+1)(d−1)+1 sprays whose centers are in general position in a hyperplane. This extends previous results by Schmerl when d=2d=2.
生成讲解博客的中文版本
生成AI智能校验的中文版本