Maths - Pure - Set Notation

∈

is an element for

∉ 

is not an element of

⊆

is a subset of

⊂

is a proper set of

{ a, b, c …}

the set with elements a, b, c…

*n*(A)

the number of elements in set A

∅

the empty set

ξ

the universal set

A’

the complement of the set A (everything that is not in set A)

N

the set of natural numbers (1, 2, 3, 4, …) (does not include 0)

Z

the set of integers (… -3, -2, -1, 0, 1, 2, 3)

**Z**+

the set of positive integers (1, 2, 3, …)

Z + 0

the set of non-negative integers (0, 1, 2, 3, …)

R

the set of real numbers (all rational and irrational numbers)

Q

the set of rational numbers

 ∪

union of sets

∩

intersection of sets

( x, y )

the ordered pair x, y

\[ a, b \]

the closed interval { x ∈ R: a ≤ x ≤ b }

\[ a, b )

the interval { x ∈ R: a ≤ x < b }

( a, b \]

the interval { x ∈ R: a < x ≤ b }

( a, b )

the open interval { x ∈ R: a < x < b }