Discrete Mathematics Symbols

a ∈ A

a is an element of A

a ∈/ A

a is not an element of A

{x ∈ D | P(x)}

the set of all x in D for which P(x) is true

R

the sets of all real numbers

Z

the sets of all integers {-3, -2, -1, 0, 1, 2 3...}

Z+

the set of positive integers, {1, 2, 3, ...}

Q

the sets of all rational numbers {e.i. 0, 1, 1/2, 22/7}

N

the set of natural numbers {0, 1, 2, 3, 4, 5,...}

A ⊆ B

A is a subset of B

A ̸⊆ B

A is not a subset of B

∀

for all

∃

there exists