English

Notes on the 33-point Erd\H{o}s--Szekeres problem

Combinatorics 2026-01-01 v1 Computational Geometry

Abstract

The determination of ES(7)ES(7) is the first open case of the planar Erd\H{o}s--Szekeres problem, where the general conjecture predicts ES(7)=33ES(7)=33. We present a SAT encoding for the 33-point case based on triple-orientation variables and a 4-set convexity criterion for excluding convex 7-gons, together with convex-layer anchoring constraints. The framework yields UNSAT certificates for a collection of anchored subfamilies. We also report pronounced runtime variability across configurations, including heavy-tailed behavior that currently dominates the computational effort and motivates further encoding refinements.

Keywords

Cite

@article{arxiv.2512.24061,
  title  = {Notes on the 33-point Erd\H{o}s--Szekeres problem},
  author = {Bogdan Dumitru},
  journal= {arXiv preprint arXiv:2512.24061},
  year   = {2026}
}
R2 v1 2026-07-01T08:45:29.309Z