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arXiv math/0009064math.LO
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关于2^λ上的良等价关系

On nice equivalence relations on 2^λ

Saharon Shelah

摘要:

这里的主要问题是关于2 ^Ω上的“简单”等价关系的下列定理可能推广到更高的基数。定理:(1)设:(a)E是2 ^Ω上的Borel二位关系,(b)E是等价关系,(c)若eta,nu在2 ^Ω上且(存在!n)(eta(n)not= nu(n)),则eta,nu不是E -等价的。则存在两两非E等价成员的2 ^Ω的完美子集。(2)而不是“E是Borel”,“E是解析的(甚至是解析关系的Borel组合)”就足够了。(3)如果E是一个Pi^1_2关系,它是一个满足V^Cohen中子句(b)+(c)的等价关系,则(1)的结论成立。

英文摘要:

The main question here is the possible generalization of the following theorem on ``simple'' equivalence relation on 2^omega to higher cardinals. Theorem: (1) Assume that: (a) E is a Borel 2-place relation on 2^omega, (b) E is an equivalence relation, (c) if eta, nu in 2^omega and (exists ! n)(eta(n) not= nu(n)), then eta, nu are not E --equivalent. Then there is a perfect subset of 2^omega of pairwise non E-equivalent members. (2) Instead of ``E is Borel'', ``E is analytic (or even a Borel combination of analytic relations)'' is enough. (3) If E is a Pi^1_2 relation which is an equivalence relation satisfying clauses (b)+(c) in V^Cohen, then the conclusion of (1) holds.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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