Submission date: 26 August 2013.

Abstract:

We provide a new criterion for embedding E_0, and apply it to equivalence relations in model theory. This generalize the results of the authors and Pierre Simon on the Borel cardinality of Lascar strong types equality, and Newelski's results about pseudo F_\sigma groups.

Mathematics Subject Classification: 03C45, 03E15

Keywords and phrases:

Full text arXiv 1308.5515: pdf, ps.