English

An attack on Zarankiewicz's problem through SAT solving

Combinatorics 2022-04-21 v2 Discrete Mathematics Logic in Computer Science

Abstract

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.

Keywords

Cite

@article{arxiv.2203.02283,
  title  = {An attack on Zarankiewicz's problem through SAT solving},
  author = {Jeremy Tan},
  journal= {arXiv preprint arXiv:2203.02283},
  year   = {2022}
}

Comments

24 pages, 2 figures. Added correctness proof of partition-generating algorithm and a new subsection on coverings

R2 v1 2026-06-24T10:02:03.898Z