Pointed-perfect-set conjecture for increasing Borel approximations to Turing equivalence
Pointed-perfect-set conjecture for increasing Borel approximations to Turing equivalence
Let be Borel equivalence relations on such that for every , and suppose . A pointed perfect set is a perfect set with the coding property used in the paper. Pointed-perfect-set conjecture. There is a pointed perfect set and an index such that
The conjecture would give a negative answer to the paper's question about whether Turing equivalence can be written as a nontrivial increasing union of Borel equivalence relations. No resolution is supplied.
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Sources & referencesView supporting material
Primary source
Adam Day and Andrew Marks, “On a question of Slaman and Steel”, arXiv:2004.00174 (2026).
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