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Minimal degrees which are $\Sigma_{2}^{0}$ but not $\Delta_{2}^{0}$

Author(s): Richard A. Shore
Journal: Proc. Amer. Math. Soc. 132 (2004), 563-565.
MSC (2000): Primary 03D28
Posted: June 17, 2003
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Abstract: We give a short proof of the existence of minimal Turing degrees which are $\Sigma_{2}^{0}$ but not $\Delta_{2}^{0}$.

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Additional Information:

Richard A. Shore
Affiliation: Department of Mathematics, Cornell University, Ithaca, New York 14853
Email: shore@math.cornell.edu

DOI: 10.1090/S0002-9939-03-07080-1
PII: S 0002-9939(03)07080-1
Keywords: Minimal degree, recursively enumerable in $0'$
Received by editor(s): August 19, 2002
Received by editor(s) in revised form: October 8, 2002
Posted: June 17, 2003
Additional Notes: This research was partially supported by NSF Grant DMS-0100035
Communicated by: Carl G. Jockusch, Jr.
Copyright of article: Copyright 2003, American Mathematical Society

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