Abstract
We study the cardinality and structural properties of the Rogers semilattice of generalized computable enumerations with arbitrary noncomputable oracles and oracles of hyperimmune Turing degree. We show the infinity of the Rogers semilattice of generalized computable enumerations of an arbitrary nontrivial family with a noncomputable oracle. In the case of oracles of hyperimmune degree we prove that the Rogers semilattice of an arbitrary infinite family includes an ideal without minimal elements and establish that the top, if present, is a limit element under the condition that the family contains the inclusion-least set.
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Original Russian Text Copyright © 2017 Faizrahmanov M.Kh.
The author was supported by the subsidy of the government task for Kazan (Volga Region) Federal University (Grant 1.1515.2017/4.6) and the Russian Foundation for Basic Research (Grant 15–01–08252).
Kazan. Translated from Sibirskiĭ Matematicheskiĭ Zhurnal, Vol. 58, No. 6, pp. 1418–1427, November–December, 2017
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Faizrahmanov, M.K. The Rogers Semilattices of Generalized Computable Enumerations. Sib Math J 58, 1104–1110 (2017). https://doi.org/10.1134/S0037446617060192
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DOI: https://doi.org/10.1134/S0037446617060192