Borel-Wadge degrees
Alessandro Andretta, Donald A. Martin (2003)
Fundamenta Mathematicae
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Two sets of reals are Borel equivalent if one is the Borel pre-image of the other, and a Borel-Wadge degree is a collection of pairwise Borel equivalent subsets of ℝ. In this note we investigate the structure of Borel-Wadge degrees under the assumption of the Axiom of Determinacy.