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Results tagged with descriptive-set-theory
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user 147031
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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An uncountable measurable subset of $\Bbb R$ containing no nonempty perfect set
Assuming the axiom of choice, there is a (may I say very natural) uncountable set of real numbers that is measure-zero with regard to any $\sigma$-finite, complete, regular measure that measures all t …
