## A Normal Form of Borel Sets of Finite Rank

### Details

Serval ID

serval:BIB_3F1A465A356C

Collection

Publications

Fund

Title

A Normal Form of Borel Sets of Finite Rank

Issued date

2008

Notes

submitted to Notre-Dame Journal of Formal Logic radically different proofs and tools than the ones in the article submitted to JSL. These proofs are close to the ones in my Ph.D. Thesis, but extremely reduced

Abstract

For each Borel set of reals A, of finite rank, we obtain a ``normal form'' of A, by finding a canonical Borel set Ω, such that A and Ω continuously reduce to each other. In more technical terms: we define simple Borel operations which are homomorphic to ordinal sum, to multiplication by a countable ordinal, and to ordinal exponentiation of base ω1 , under the map which sends every Borel set A of finite rank to its Wadge degree.

Create date

23/01/2008 19:45

Last modification date

18/11/2016 13:08