Definability issues in the ω-Turing degrees

TitleDefinability issues in the ω-Turing degrees
Publication TypeJournal Article
Year of Publication2018
AuthorsSariev A, Ganchev H
JournalAnnuaire de l’Université de Sofia “St. Kliment Ohridski”. Faculté de Mathématiques et Informatique
Start Page45
ISSN1313-9215 (Print), ISSN 2603-5529 (Online)
Keywordsdefinability, degree structures, jump, Turing reducibility, ω-Turing degrees

We show the equivalence of the first order definabilities of the jump of the least element and of the jump operator in the upper semilattice of the ω-Turing degrees.

2000 MSC

03D28, 03D30

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