Jump to content

Simple set

From Wikipedia, the free encyclopedia
This is an old revision of this page, as edited by MathMartin (talk | contribs) at 11:04, 14 August 2005 (added ==Definition==). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

In computability theory a simple set is an example of a set which is recursively enumerable but not recursive.

Definition

A subset S of the natural numbers N is called simple if it satisfies the following properties

  1. N\S is infinite
  2. S is recursively enumerable
  3. SX ≠ ø for any infinite recursively enumerable set X