Low upper bounds of ideals

Publisher: Cambridge University Press

E-ISSN: 1943-5886|74|2|517-534

ISSN: 0022-4812

Source: The Journal of Symbolic Logic, Vol.74, Iss.2, 2009-06, pp. : 517-534

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

We show that there is a low T-upper bound for the class of K-trivial sets, namely those which are weak from the point of view of algorithmic randomness. This result is a special case of a more general characterization of ideals in T-degrees for which there is a low T-upper bound.