1.3.7.3 Complement of a Set
The complement of a set 
, denoted as 
or
is a set that contains all the elements that belong to the universal set 
but not to . This can be formally represented as:
is the set of all elements 
in the universal set such that the element is not in set .
Example 1.21. Let's say we have a universal set , containing all English letters {
, 
, 
, ..., 
} and a set , containing vowels {, 
, 
, 
, 
}, represented by Fig 1.8. As a result, the complement of set would be the set of consonants, represented as: = {, , ..., }.