Difference between revisions of "Countable"
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A set X is countable if and only if there is a bijection from X to the set of [[Natural Numbers]]. Countable sets include the set of [[integer]]s and the set of [[rational number]]s. | A set X is countable if and only if there is a bijection from X to the set of [[Natural Numbers]]. Countable sets include the set of [[integer]]s and the set of [[rational number]]s. | ||
| − | [[Category: | + | [[Category:Set theory]] |
Revision as of 04:46, March 31, 2007
A set X is countable if and only if there is a bijection from X to the set of Natural Numbers. Countable sets include the set of integers and the set of rational numbers.