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Intrinsic Reducibilities
Author(s) -
McNicholl Timothy H.
Publication year - 2000
Publication title -
mathematical logic quarterly
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.473
H-Index - 28
eISSN - 1521-3870
pISSN - 0942-5616
DOI - 10.1002/1521-3870(200008)46:3<393::aid-malq393>3.0.co;2-h
Subject(s) - mathematics , countable set , jump , discrete mathematics , physics , quantum mechanics
Let $\alpha < \omega _1 ^{\rm CK}$ . We show that for many reducibilities, the requirement that a relation be intrinsically reducible to the α ‐th jump of a countable mode A has a syntactic equivalent. Furthermore, we show that many reducibilities coincide in such a situation.