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Embedding Lattices with Top Preserved Below NonGL2 Degrees
, 1997
"... this paper, we answer this question by showing that every recursively presented lattice can be embedded into D (0 ..."
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this paper, we answer this question by showing that every recursively presented lattice can be embedded into D (0
Generalized high degrees have the complementation property
 Journal of Symbolic Logic
"... Abstract. We show that if d ∈ GH1 then D( ≤ d) has the complementation property, i.e. for all a < d there is some b < d such that a ∧ b = 0 and a ∨ b = d. §1. Introduction. A major theme in the investigation of the structure of the Turing degrees, (D, ≤T), has been the relationship between the order ..."
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Cited by 3 (0 self)
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Abstract. We show that if d ∈ GH1 then D( ≤ d) has the complementation property, i.e. for all a < d there is some b < d such that a ∧ b = 0 and a ∨ b = d. §1. Introduction. A major theme in the investigation of the structure of the Turing degrees, (D, ≤T), has been the relationship between the order theoretic properties of a degree and its complexity of definition in arithmetic as expressed by the Turing jump operator which embodies a single step in the hierarchy of quantification. For example, there is a long history of results showing that 0 ′
Jumps of minimal degrees below 0
 J. London Math. Soc
, 1996
"... Abstract. We show that there is a degree a REA in and low over 0 ′ such that no minimal degree below 0 ′ jumps to a degree above a. We also show that every nonlow r.e. degree bounds a nonlow minimal degree. Introduction. An important and longstanding area of investigation in recursion theory has be ..."
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Abstract. We show that there is a degree a REA in and low over 0 ′ such that no minimal degree below 0 ′ jumps to a degree above a. We also show that every nonlow r.e. degree bounds a nonlow minimal degree. Introduction. An important and longstanding area of investigation in recursion theory has been the relationship between quantifier complexity of the definitions of sets in arithmetic as expressed by the jump operator and the basic notion of relative computability as expressed by the ordering of the (Turing) degrees. In this paper we
RESTRICTED JUMP INTERPOLATION IN THE D.C.E. DEGREES
, 2009
"... It is shown that for any 2computably enumerable Turing degree l, any computably enumerable degree a, and any Turing degree s, if l ′ = 0 ′, l < a, s ≥ 0 ′ , and s is c.e. in a, then there is a 2computably enumerable degree x with the following properties: (1) l < x < a, and (2) x ′ = s. 1 ..."
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It is shown that for any 2computably enumerable Turing degree l, any computably enumerable degree a, and any Turing degree s, if l ′ = 0 ′, l < a, s ≥ 0 ′ , and s is c.e. in a, then there is a 2computably enumerable degree x with the following properties: (1) l < x < a, and (2) x ′ = s. 1
Annals of Mathematics FirstOrder Theory of the Degrees of Recursive Unsolvability
"... JSTOR is a notforprofit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JS ..."
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JSTOR is a notforprofit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. Annals of Mathematics is collaborating with JSTOR to digitize, preserve and extend access to Annals of