Article contents
On the jump classes of noncuppable enumeration degrees
Published online by Cambridge University Press: 12 March 2014
Abstract
We prove that for every Σ20 enumeration degree b there exists a noncuppable Σ20 degree a > 0e such that and . This allows us to deduce, from results on the high/low jump hierarchy in the local Turing degrees and the jump preserving properties of the standard embedding , that there exist Σ20 noncuppable enumeration degrees at every possible—i.e., above low1—level of the high/low jump hierarchy in the context of .
- Type
- Research Article
- Information
- Copyright
- Copyright © Association for Symbolic Logic 2011
References
REFERENCES
- 2
- Cited by