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Principal filters definable by parameters in 𝓔bT†

  • ANGSHENG LI (a1), WEILIN LI (a2), YICHENG PAN (a3) and LINQING TANG (a4)

Abstract

We show that there exist c.e. bounded Turing degrees a, b such that 0 < a < 0β€², and that for any c.e. bounded Turing degree x, we have b ∨ x = 0β€² if and only if x β‰₯ a. The result gives an unexpected definability theorem in the structure of bounded Turing reducibility.

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Principal filters definable by parameters in 𝓔bT†

  • ANGSHENG LI (a1), WEILIN LI (a2), YICHENG PAN (a3) and LINQING TANG (a4)

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