Turing reducibility
E679186
Turing reducibility is a central computability-theoretic notion that compares the relative computational difficulty of decision problems by allowing one problem to be solved using an oracle for another.
Observed surface forms (1)
| Surface form | Occurrences |
|---|---|
| Turing reductions | 1 |
Statements (50)
| Predicate | Object |
|---|---|
| instanceOf |
computability-theoretic notion
ⓘ
reducibility notion ⓘ relative computability concept ⓘ |
| allows |
arbitrary adaptive oracle queries
ⓘ
unbounded number of oracle queries ⓘ |
| alsoKnownAs |
Turing reducibility relation
ⓘ
Turing reduction NERFINISHED ⓘ |
| appliesTo |
decision problems
ⓘ
sets of integers ⓘ subsets of ω ⓘ |
| basedOn | oracle Turing machines ⓘ |
| captures |
relative computational difficulty
ⓘ
relative solvability of problems ⓘ |
| compares |
decision problems
ⓘ
languages over finite alphabets ⓘ sets of natural numbers ⓘ |
| definition | A is Turing reducible to B if A is decidable by a Turing machine with oracle for B ⓘ |
| equivalenceRelation | A ≡_T B iff A ≤_T B and B ≤_T A ⓘ |
| field |
computability theory
ⓘ
mathematical logic ⓘ theoretical computer science NERFINISHED ⓘ |
| formalCondition | A ≤_T B iff there exists an oracle Turing machine M^B that decides membership in A ⓘ |
| generalizes |
Turing computability without oracles
ⓘ
many-one reducibility ⓘ |
| historicalPeriod | 1930s ⓘ |
| implies | many-one reducibility implies Turing reducibility ⓘ |
| induces |
equivalence relation of Turing equivalence
ⓘ
preorder on sets of natural numbers ⓘ |
| isWeakerThan |
many-one reducibility
ⓘ
one-one reducibility ⓘ truth-table reducibility ⓘ |
| keyProperty |
not antisymmetric on all sets
ⓘ
reflexive on all sets ⓘ transitive on all sets ⓘ |
| originator | Alan Turing NERFINISHED ⓘ |
| preserves | Turing computability ⓘ |
| relatedConcept |
Turing degree
NERFINISHED
ⓘ
many-one reducibility ⓘ oracle Turing machine ⓘ polynomial-time Turing reducibility ⓘ truth-table reducibility ⓘ weak truth-table reducibility ⓘ |
| symbol | ≤_T ⓘ |
| usedIn |
classification of unsolvable problems
ⓘ
degree theory ⓘ study of the analytical hierarchy ⓘ study of the arithmetical hierarchy ⓘ |
| usedToDefine |
Turing degrees
ⓘ
degree of unsolvability ⓘ relative computability hierarchy ⓘ |
Referenced by (2)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
Turing reductions