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The density of the meet-inaccessible r. e. degrees

Published online by Cambridge University Press:  12 March 2014

Zhang Qinglong
Zhang Qinglong*
Affiliation:
Institute of Software, Academia Sinica, Beijing 100080, China
*
Department of Mathematics, Statistics and Computer Science, University of Illinois, at Chicago, Chicago, Illinois 60680.
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Abstract

In this paper it is shown that the meet-inaccessible degrees are dense in R. The construction uses an 0′-priority argument. As a consequence, the meet-inaccessible degrees and the meet-accessible degrees give a partition of R into two sets, either of which is a nontrivial dense subset of R and generates R − {0} under joins (thus an automorphism base of R).

Information

Type
Research Article
Information
The Journal of Symbolic Logic , Volume 57 , Issue 2 , June 1992 , pp. 585 - 596
Copyright
Copyright © Association for Symbolic Logic 1992

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References

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