The
absolute complement — or simply
complement— of a
A contains all the in the that do not belong to
A. The complement of
A can be denoted as
AC
or
A′.
AC={x∣x∈/A}
The above set can be read as
the set of all numbers x such that x is not an element of set A.
In a , the complement of
A is shown by coloring the area outside
A.
For instance, consider the as a universal set. If
A is the set of integers, then the complement of
A contains the integers and zero.
UAAC={…,-3,-2,-1,0,1,2,3,…}={1,2,3,…}={0,-1,-2,-3,…}