Basic terminology and notation for sets
Set --- a collection of objects.
This is not a definition!
This is a fundamental notion in mathematics that cannot be defined!
The objects in a set are also called the elements, or members, of the
set. They are also said to belong to the set.
x?S means “x is an element of (belongs to) S”
x?S means “x is not an element of S”
Two ways to describe a set:
1) List the members of 2) Use set builder notation
S={1,2,3,4,5,6,7,8,9} S={x | x is a positive integer less than 10}
S={1,2,…,100} S={x | x is an integer and 1? x ? 100}
S={2,4,6,8,…} S={x | x is an even positive integer}