Set

:This article is about sets in mathematics. For other senses, see set (disambiguation).

Unions

There are several ways to construct new sets from existing ones.

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Two sets can be "added" together. The union of A and B, denoted by A U B, is the set of all things which are members of either A or B.

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The union of A and B

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Examples:

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:*{1, 2} U {red, white} = {1, 2, red, white}

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:*{1, 2, green} U {red, white, green} = {1, 2, red, white, green}

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:*{1, 2} U {1, 2} = {1, 2}

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Some basic properties of unions:

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:*A U B   =   B U A

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:*A  is a subset of  A U B

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:*A U A   =  A

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:*A U ø   =  A

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For more information about unions of sets, see Union (set theory).

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