English

A Groszek-Laver pair of undistinguishable $E_0$ classes

Logic 2016-01-15 v1

Abstract

A generic extension L[x,y]L[x,y] of LL by reals x,yx,y is defined, in which the union of E0\mathsf E_0-classes of xx and yy is a Π21\Pi^1_2 set, but neither of these two E0\mathsf E_0-classes is separately ordinal-definable.

Cite

@article{arxiv.1601.03477,
  title  = {A Groszek-Laver pair of undistinguishable $E_0$ classes},
  author = {Mohammad Golshani and Vladimir Kanovei and Vassily A Lyubetsky},
  journal= {arXiv preprint arXiv:1601.03477},
  year   = {2016}
}
R2 v1 2026-06-22T12:29:11.176Z