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Some results on the upper-semilattice of R.E. m-degrees inside a single R.E. tt-degree

Author: Angel Ditchev

In this paper it is shown that: 1) There exists such a tt-degree which contains infinitely
many m-degrees of the type of $\omega^k$ for any positive natural number k; 2) There exists
such a tt-degree which contains infinitely many m-degrees of the type of $\stQQ$ of rational
numbers.

Annotation in PDF format: (PDF document 28Kb)
Keywords: m-degrees, tt-degrees, upper semilattice
2000 MSC: 03D25, 03D30, 03D45, 03C57