Article
Keywords:
countable Borel equivalence relation; forcing
Summary:
Given a countable Borel equivalence relation, I introduce an invariant measuring how difficult it is to find Borel sets separating its equivalence classes. I evaluate these invariants in several standard generic extensions.
References:
                        
[2] Kanovei V.: 
Borel Equivalence Relations: Structure and Classification. University Lecture Series, 44, American Mathematical Society, Providence, 2008. 
DOI 10.1090/ulect/044/06 | 
MR 2441635[3] Zapletal J.: 
Forcing Idealized. Cambridge Tracts in Mathematics, 174, Cambridge University Press, Cambridge, 2008. 
MR 2391923 | 
Zbl 1140.03030[4] Zapletal J.: Hypergraphs and proper forcing. available at arXiv:1710.10650 [math.LO] (2017), 64 pages.