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Properly enumeration degrees and the high/low hierarchy

Published online by Cambridge University Press:  12 March 2014

Matthew Giorgi ,
Andrea Sorbi  and
Yue Yang
Matthew Giorgi
Affiliation:
Dipartimento di Scienze Matematiche ed Informatiche, “Roberto Magari”, Pian dei Mantellini 44, 53100 Siena, Italy, E-mail: Matthew.Giorgi@ge.com
Andrea Sorbi
Affiliation:
Dipartimento di Scienze Matematiche ed Informatiche, “Roberto Magari”, Pian dei Mantellini 44, 53100 Siena, Italy, E-mail: sorbi@unisi.it
Yue Yang
Affiliation:
Department of Mathematics, Faculty of Science, National University of Singapore, Lower Kent Ridge Road, Singapore, 119260, E-mail: matyangy@nus.edu.sg
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Abstract

We show that there exist downwards properly (in fact noncuppable) e-degrees that are not high. We also show that every high e-degree bounds a noncuppable e-degree.

Type
Research Article
Information
The Journal of Symbolic Logic , Volume 71 , Issue 4 , December 2006 , pp. 1125 - 1144
Copyright
Copyright © Association for Symbolic Logic 2006

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References

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