A hierarchy for cuppable degrees
نویسندگان
چکیده
منابع مشابه
Non-cuppable enumeration degrees via finite injury
We exhibit finite injury constructions of a high Σ2 enumeration degree incomparable with all intermediate ∆2 enumeration degrees, as also of both an upwards properly Σ2 high and a low2 noncuppable Σ 0 2 enumeration degree†. We also outline how to apply the same methods to prove that, for every Σ2 enumeration degree b there exists a noncuppable degree a such that b′ ≤ a′ and a′′ ≤ b′′, thus show...
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ژورنال
عنوان ژورنال: Illinois Journal of Mathematics
سال: 2000
ISSN: 0019-2082
DOI: 10.1215/ijm/1256060420