## setA finite or infinite collection of objects known as elements.
Sets are one of the most basic and important concepts in mathematics. An
example of finite set is the set of whole numbers from 1 to 58; an example
of an infinite set is the set of all the rational
numbers. Two sets are equal if, and only if, they contain the same objects.
Standard notation uses braces around the list of elements, as in: {red,
green, blue}. If A and B are two sets and every x in
A is also contained in B, then A is said to be a subset
of B. Every set has as braces around the list of elements, as in:
{red, green, blue}. If A and B are two sets and every x
in A is also contained in B, then A is said to be a
subset of B. Every set has as subsets itself, known as the improper
subset, and the empty set. The
union of a collection of sets S = {S_{1},
S_{2}, S_{3}, ...} is the set of all elements
contained in at least one of the sets S_{1}, S_{2},
S_{3}, ... The intersection of a collection
of sets T = {T_{1}, T_{2}, T_{3},
...} is the set of all elements contained in all of the sets. The set of
all subsets of X is called its power set and is
denoted 2^{X} or P(X). ## Related entries## Related category• SETS AND SET THEORY | |||||

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