English

Regressive versions of Hindman's Theorem

Logic 2025-06-12 v4 Combinatorics

Abstract

When the Canonical Ramsey's Theorem by Erd\H{o}s and Rado is applied to regressive functions one obtains the Regressive Ramsey's Theorem by Kanamori and McAloon. Taylor proved a "canonical" version of Hindman's Theorem, analogous to the Canonical Ramsey's Theorem. We introduce the restriction of Taylor's Canonical Hindman's Theorem to a subclass of the regressive functions, the λ\lambda-regressive functions, relative to an adequate version of min-homogeneity and prove some results about the Reverse Mathematics of this Regressive Hindman's Theorem and of natural restrictions of it. In particular we prove that the first non-trivial restriction of the principle is equivalent to Arithmetical Comprehension. We furthermore prove that this same principle strongly computably reduces the well-ordering-preservation principle for base-ω\omega exponentiation.

Keywords

Cite

@article{arxiv.2207.08554,
  title  = {Regressive versions of Hindman's Theorem},
  author = {Lorenzo Carlucci and Leonardo Mainardi},
  journal= {arXiv preprint arXiv:2207.08554},
  year   = {2025}
}

Comments

Corrected proofs of Proposition 2. Added Theorem 2

R2 v1 2026-06-25T01:00:26.681Z