English

A separation result for countable unions of Borel rectangles

Logic 2019-06-12 v1

Abstract

We provide dichotomy results characterizing when two disjoint analytic binary relations can be separated by a countable union of Σ10 ⁣× ⁣Σξ0{\bf\Sigma}^0_1 \!\times\! {\bf\Sigma}^0_\xi sets, or by a Π10 ⁣× ⁣Πξ0{\bf\Pi}^0_1 \!\times\! {\bf\Pi}^0_\xi set.

Cite

@article{arxiv.1708.00642,
  title  = {A separation result for countable unions of Borel rectangles},
  author = {Dominique Lecomte},
  journal= {arXiv preprint arXiv:1708.00642},
  year   = {2019}
}
R2 v1 2026-06-22T21:04:28.123Z