加载中…
We prove the following dichotomy. Given an analytic equivalence relation , either or else any Borel homomorphism from to is “very far from a reduction”, specifically, it factors, on a comeager set, through the projection map for some . As a corollary, we prove that is a prime equivalence relation, answering a question on Clemens.

生成讲解博客的中文版本

生成AI智能校验的中文版本