{ "id": "math/9507213", "version": "v1", "published": "1995-07-26T00:00:00.000Z", "updated": "1995-07-26T00:00:00.000Z", "title": "On a Glimm -- Effros dichotomy and an Ulm--type classification in Solovay model", "authors": [ "Vladimir Kanovei" ], "categories": [ "math.LO" ], "abstract": "We prove that in Solovay model every OD equivalence E on reals either admits an OD reduction to the equality on the set of all countable (of length < omega_1) binary sequences, or continuously embeds E_0, the Vitali equivalence. If E is a Sigma_1^1 (resp. Sigma_1^2) relation then the reduction in the ``either'' part can be chosen in the class of all Delta_1 (resp. Delta_2) functions. The proofs are based on a topology generated by OD sets.", "revisions": [ { "version": "v1", "updated": "1995-07-26T00:00:00.000Z" } ], "analyses": { "keywords": [ "solovay model", "ulm-type classification", "effros dichotomy", "od equivalence", "vitali equivalence" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "1995math......7213K" } } }