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Results tagged with descriptive-set-theory
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user 151109
Descriptive Set Theory is the study of definable subsets of Polish spaces, where definable is taken to mean from the Borel or projective hierarchies. Other topics include infinite games and determinacy, definable equivalence relations and Borel reductions between them, Polish groups, and effective descriptive set theory.
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Pathological behavior of Borel sets?
The following statement is equivalent to the perfect set property for Pi^1_1, hence not decidable in ZFC: Every sigma-compact subset of R^2 which contains uncountably many pairwise disjoint topologic …
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