English

Thicket Density

Logic 2023-06-22 v4

Abstract

We define a new type of "shatter function" for set systems that satisfies a Sauer-Shelah type dichotomy, but whose polynomial-growth case is governed by Shelah's 2-rank instead of VC dimension. We identify the rate of growth of this shatter function, the quantity analogous to VC density, with Shelah's ω\omega-rank.

Cite

@article{arxiv.1702.03956,
  title  = {Thicket Density},
  author = {Siddharth Bhaskar},
  journal= {arXiv preprint arXiv:1702.03956},
  year   = {2023}
}

Comments

15 pages, 7 figures

R2 v1 2026-06-22T18:17:20.832Z