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Relative enumerability in the difference hierarchy

Published online by Cambridge University Press:  12 March 2014

Marat M. Arslanov ,
Geoffrey L. Laforte  and
Theodore A. Slaman
Marat M. Arslanov
Affiliation:
13 Karbishev St. No. 109, Kazan 420087, Russia, E-mail: marat@ksu.ru
Geoffrey L. Laforte
Affiliation:
Institute for Human and Machine Cognition, University of West Florida, 11000 University Parkway, Pensacola, FL 32514, USA, E-mail: glaforte@coginst.uwf.edu
Theodore A. Slaman
Affiliation:
Department of Mathematics, The University of California, Berkeley, CA 94720-3840, USA, E-mail: slaman@math.berkeley.edu
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Abstract

We show that the intersection of the class of 2-REA degrees with that of the ω-r.e. degrees consists precisely of the class of d.r.e. degrees. We also include some applications and show that there is no natural generalization of this result to higher levels of the REA hierarchy.

Type
Research Article
Information
The Journal of Symbolic Logic , Volume 63 , Issue 2 , June 1998 , pp. 411 - 420
Copyright
Copyright © Association for Symbolic Logic 1998

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References

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