English

Erd\H{o}s-Selfridge Theorem for Nonmonotone CNFs

Discrete Mathematics 2022-01-05 v1 Data Structures and Algorithms

Abstract

In an influential paper, Erd\H{o}s and Selfridge introduced the Maker-Breaker game played on a hypergraph, or equivalently, on a monotone CNF. The players take turns assigning values to variables of their choosing, and Breaker's goal is to satisfy the CNF, while Maker's goal is to falsify it. The Erd\H{o}s-Selfridge Theorem says that the least number of clauses in any monotone CNF with kk literals per clause where Maker has a winning strategy is Θ(2k)\Theta(2^k). We study the analogous question when the CNF is not necessarily monotone. We prove bounds of Θ(2k)\Theta(\sqrt{2}\,^k) when Maker plays last, and Ω(1.5k)\Omega(1.5^k) and O(rk)O(r^k) when Breaker plays last, where r=(1+5)/21.618r=(1+\sqrt{5})/2\approx 1.618 is the golden ratio.

Cite

@article{arxiv.2201.00968,
  title  = {Erd\H{o}s-Selfridge Theorem for Nonmonotone CNFs},
  author = {Md Lutfar Rahman and Thomas Watson},
  journal= {arXiv preprint arXiv:2201.00968},
  year   = {2022}
}
R2 v1 2026-06-24T08:39:24.313Z