Weak density and cupping in the d-r.e. degrees

DOI10.1007/BF02937291zbMath0691.03023MaRDI QIDQ582288

Philip Watson, S. Barry Cooper, Steffen Lempp

Publication date: 1989

Published in: Israel Journal of Mathematics (Search for Journal in Brave)

zbMATH Keywords

cuppingd-r.e. degreesn-r.e. degreesweak density

Mathematics Subject Classification ID

Recursively (computably) enumerable sets and degrees (03D25) Other degrees and reducibilities in computability and recursion theory (03D30) Hierarchies of computability and definability (03D55)

Related Items

Bi-isolation in the d.c.e. degrees, Infima of d.r.e. degrees, Interpolating \(d\)-r.e. and REA degrees between r.e. degrees, Intervals containing exactly one c.e. degree, The jump is definable in the structure of the degrees of unsolvability, Extending and interpreting Post's programme, Strong degrees of categoricity and weak density, Strong noncuppability in low computably enumerable degrees, The weak density of properly d-r. e. branching degree in the d-r. e. degrees, Complementing cappable degrees in the difference hierarchy., The density of the low\(_ 2\) \(n\)-r.e. degrees, The d.r.e. degrees are not dense, Infima in the d.r.e. degrees, On Downey's conjecture, Infima of d.r.e. Degrees, Isolation in the CEA hierarchy, 1998–99 Annual Meeting of the Association for Symbolic Logic, 2002 European Summer Meeting of the Association for Symbolic Logic Logic Colloquium '02, Non-cupping, measure and computably enumerable splittings, 2008 European Summer Meeting of the Association for Symbolic Logic. Logic Colloquium '08, Splitting in 2-computably enumerable degrees with avoiding cones, A non-splitting theorem for d.r.e. sets, Relative enumerability in the difference hierarchy, Nonisolated degrees and the jump operator, Isolation and lattice embeddings

Cites Work

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• Complementation in the Turing degrees
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• D.R.E. Degrees and the Nondiamond Theorem
• The strong anticupping property for recursively enumerable degrees
• A Dichotomy of the Recursively Enumerable Sets