Annals of Pure and Applied Logic 94 (1-3):97-125 (1998)

Post in 1944 began studying properties of a computably enumerable set A such as simple, h-simple, and hh-simple, with the intent of finding a property guaranteeing incompleteness of A . From the observations of Post and Myhill , attention focused by the 1950s on properties definable in the inclusion ordering of c.e. subsets of ω, namely E = . In the 1950s and 1960s Tennenbaum, Martin, Yates, Sacks, Lachlan, Shoenfield and others produced a number of elegant results relating ∄-definable properties of A , like maximal, hh-simple, atomless, to the information content of A . Harrington and Soare gave an answer to Post's program for definable properties by producing an ∄-definable property Q which guarantees that A is incomplete and noncomputable, but developed a new Δ 3 0 -automorphism method to prove certain other properties are not ∄-definable. In this paper we introduce new ∄-definable properties relating the ∄-structure of A to deg, which answer some open questions. In contrast to Q we exhibit here an ∄-definable property T which allows such a rapid flow of elements into A that A must be complete even though A may possess many other properties such as being promptly simple. We also present a related property NL which has a slower flow but fast enough to guarantee that A is not low, even though A may possess virtually all other related lowness properties and A may simultaneously be promptly simple
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DOI 10.1016/s0168-0072(97)00069-9
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References found in this work BETA

Computability and Recursion.Robert I. Soare - 1996 - Bulletin of Symbolic Logic 2 (3):284-321.
Recursively Enumerable Generic Sets.Wolfgang Maass - 1982 - Journal of Symbolic Logic 47 (4):809-823.

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Citations of this work BETA

Duality, Non-Standard Elements, and Dynamic Properties of R.E. Sets.V. Yu Shavrukov - 2016 - Annals of Pure and Applied Logic 167 (10):939-981.
Orbits of Computably Enumerable Sets: Low Sets Can Avoid an Upper Cone.Russell Miller - 2002 - Annals of Pure and Applied Logic 118 (1-2):61-85.
Definable Incompleteness and Friedberg Splittings.Russell Miller - 2002 - Journal of Symbolic Logic 67 (2):679-696.

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