The Zarankiewicz function gives, for a chosen matrix and minor size, the maximum number of ones in a binary matrix not containing an all-one minor. Tables of this function for small arguments have been compiled, but errors are known in them. We both correct the errors and extend these tables in the case of square minors by expressing the problem of finding the value at a specific point as a series of Boolean satisfiability problems, exploiting permutation symmetries for a significant reduction in the work needed. When the ambient matrix is also square we also give all non-isomorphic examples of matrices attaining the maximum, up to the aforementioned symmetries; it is found that most maximal matrices have some form of symmetry.
翻译:Zarankiiewicz 函数为选定的矩阵和小尺寸提供了一个二进制矩阵中不包含全部小号的最大数量。 已经为小参数汇编了该函数的表格, 但这些表格中存在错误。 我们既更正错误, 也扩展了这些表格中涉及平方未成年人的表格, 表达在特定点找到该值的问题, 将其作为一系列布利安可对称性问题, 利用对称性以大幅缩减所需工作。 当环境矩阵也为平方时, 我们还给出了所有达到最大值、 直至上述对称性的非异形矩阵实例; 发现大多数最大矩阵有某种形式的对称性 。