Difference between revisions of "Element"
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<math>A=\{1,\,2,\,3,\,4\}</math> means set <math>A</math> contains the elements 1, 2, 3 and 4. | <math>A=\{1,\,2,\,3,\,4\}</math> means set <math>A</math> contains the elements 1, 2, 3 and 4. | ||
| − | To show that an element is contained within a set, the <math>\in</math> symbol is used. | + | To show that an element is contained within a set, the <math>\in</math> symbol is used. The opposite of <math>\in</math> is <math>\notin</math>, which means the element is not contained within the set. |
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=== Sets as Elements === | === Sets as Elements === | ||
| − | Elements can also be sets. For example, <math>B = \{1,\,2,\,\{3,\,4\}\}</math>. The elements of <math>B</math> are <math>1</math>, <math>2</math>, and | + | Elements can also be sets. For example, <math>B = \{1,\,2,\,\{3,\,4\}\}</math>. The elements of <math>B</math> are <math>1</math>, <math>2</math>, and <math>\{3,\,4\}</math>. |
== See Also == | == See Also == | ||
*[[Cardinality]] | *[[Cardinality]] | ||
*[[Set theory]] | *[[Set theory]] | ||
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| + | [[Category:Set theory]] | ||
| + | [[Category:Definition]] | ||
Latest revision as of 15:59, 3 April 2012
This article is a stub. Help us out by expanding it.
An element, also called a member, is an object contained within a set or class.
means set 
contains the elements 1, 2, 3 and 4.
To show that an element is contained within a set, the 
symbol is used. The opposite of is 
, which means the element is not contained within the set.
Sets as Elements
Elements can also be sets. For example, 
. The elements of 
are 
, 
, and 
.
