Recursive Set
A set S of integers is said to be recursive if there is a total recursive function f(x) such that f(x)=1 for x in S and f(x)=0 for x not in S. Any recursive set is also recursively enumerable.
Finite sets, sets with finite complements, the odd numbers, and the prime numbers are all examples of recursive sets. The union and intersection of two recursive sets are themselves recursive, as is the complement of a recursive set.
See also
Recursively Enumerable Set, Recursively UndecidableThis entry contributed by Alex Sakharov (author's link)
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References
Davis, M. Computability and Unsolvability. New York: Dover 1982.Rogers, H. Theory of Recursive Functions and Effective Computability. Cambridge, MA: MIT Press, 1987.Referenced on Wolfram|Alpha
Recursive SetCite this as:
Sakharov, Alex. "Recursive Set." From MathWorld--A Wolfram Resource, created by Eric W. Weisstein. https://mathworld.wolfram.com/RecursiveSet.html