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Cupping Δ20 enumeration degrees to 0e′†

Published online by Cambridge University Press:  01 February 2009

MARIYA IVANOVA SOSKOVA  and
GUOHUA WU
MARIYA IVANOVA SOSKOVA
Affiliation:
Department of Pure Mathematics, University of Leeds, Leeds LS2 9JT, United Kingdom Email: mariya@maths.leeds.ac.uk
GUOHUA WU
Affiliation:
School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 639798, Republic of Singapore Email: guohua@ntu.edu.sg
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Abstract

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In this paper we prove that every non-zero Δ20e-degree is cuppable to 0e′ by a 1-generic Δ20e-degree (and is thus low and non-total), and that every non-zero ω-c.e. e-degree is cuppable to 0e′ by an incomplete 3-c.e. e-degree.

Type
Paper
Information
Mathematical Structures in Computer Science , Volume 19 , Special Issue 1: Theory and Applications of Models of Computation (TAMC) , February 2009 , pp. 169 - 191
Copyright
Copyright © Cambridge University Press 2009

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