Difference between revisions of "Cardinality"

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For [[finite]] [[set]]s, the '''cardinality''' of a set is the number of elements in that set.  For [[infinite]] sets, the cardinality of a set S is the least [[cardinal]] which can be put in [[bijection]] with S.  The notion of cardinalities for infinite sets is due to Georg Cantor and is one aspect of the field of [[set theory]].
 
For [[finite]] [[set]]s, the '''cardinality''' of a set is the number of elements in that set.  For [[infinite]] sets, the cardinality of a set S is the least [[cardinal]] which can be put in [[bijection]] with S.  The notion of cardinalities for infinite sets is due to Georg Cantor and is one aspect of the field of [[set theory]].
  
See also:
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== See Also ==
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* [[Injection]]
 
* [[Injection]]
 
* [[Surjection]]
 
* [[Surjection]]

Revision as of 23:46, 30 October 2006

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For finite sets, the cardinality of a set is the number of elements in that set. For infinite sets, the cardinality of a set S is the least cardinal which can be put in bijection with S. The notion of cardinalities for infinite sets is due to Georg Cantor and is one aspect of the field of set theory.


See Also