학술논문
Iterated Priority Arguments in Descriptive Set Theory
Document Type
Working Paper
Source
Subject
Language
Abstract
We present the true stages machinery and illustrate its applications to descriptive set theory. We use this machinery to provide new proofs of the Hausdorff-Kuratowski and Wadge theorems on the structure of ${\mathbf \Delta}^0_\xi$, Louveau and Saint-Raymond's separation theorem, and Louveau's separation theorem.