Low (computability)

Low (computability)

In computability theory, a Turing degree ["X"] is low if the Turing jump ["X"′] is 0′, which is the least possible degree in terms of Turing reducibility for the jump of a set. Since every set is computable from its jump, any low set is computable in 0′. A set is low if it has low degree.

More generally, a set "X" is generalized low if it satisfies "X"′ ≡T "X" + 0′.

ee also

*High (computability)

*Low Basis Theorem

References

Soare, R. "Recursively enumerable sets and degrees." Perspectives in Mathematical Logic. Springer-Verlag, Berlin, 1987. ISBN 3-540-15299-7


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