Turing degrees

E679185

Turing degrees are an abstract classification of sets of natural numbers or decision problems according to their relative level of algorithmic unsolvability or computational complexity under Turing reducibility.

All labels observed (2)

Label Occurrences
Turing degrees canonical 3
Turing degree 1

How this entity was disambiguated

Statements (50)

Predicate Object
instanceOf equivalence classes under Turing reducibility
mathematical concept
structure in computability theory
basedOn Turing reducibility
captures relative algorithmic unsolvability
relative computational complexity
connectedTo effective descriptive set theory
set of reals under Turing reducibility
definedOn decision problems
sets of natural numbers
equivalenceClassOf sets of natural numbers mutually Turing reducible to each other
equivalenceRelation mutual Turing reducibility
field computability theory
mathematical logic
recursion theory
formalizedIn second-order arithmetic
hasBottomElement degree of computable sets
hasOpenProblems automorphism group of the Turing degrees
exact lattice-theoretic properties of the degrees
hasOperation join
hasProperty contains high and low degrees
contains incomparable degrees
contains minimal degrees
every nonzero degree bounds a minimal degree
not a lattice under Turing reducibility
uncountable set of degrees
hasStructure upper semilattice
hasTopElement degree of the halting problem
introducedInField mid 20th century computability theory
namedAfter Alan Turing
orderType partial order under Turing reducibility
relatedTo Medvedev degrees
Muchnik degrees
Turing jump
arithmetical hierarchy
linked to: Kleene hierarchy

degrees of unsolvability
hyperarithmetical hierarchy
many-one degrees
truth-table degrees
studiedBy Alan Turing
Emil Post
Lachlan
Sacks
Shore
Slaman
Stephen Kleene
symbol D_T
usedFor analyzing the structure of unsolvable problems
classifying decision problems by relative computability
studying relative computability of real numbers

How these facts were elicited

Referenced by (4)

Full triples — surface form annotated when it differs from this entity's canonical label.

Computability Theory fieldOfStudy Turing degrees
Kleene hierarchy relatedTo Turing degrees
Turing reducibility relatedConcept Turing degree
linked to: Turing degrees