The Π3-theory of the Computably Enumerable Turing Degrees Is Undecidable
نویسندگان
چکیده
We show the undecidability of the Π3-theory of the partial order of computably enumerable Turing degrees.
منابع مشابه
Computably Enumerable Sets and Quasi-Reducibility
We consider the computably enumerable sets under the relation of Qreducibility. We first give several results comparing the upper semilattice of c.e. Q-degrees, 〈RQ,≤Q 〉, under this reducibility with the more familiar structure of the c.e. Turing degrees. In our final section, we use coding methods to show that the elementary theory of 〈RQ,≤Q 〉 is undecidable.
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