The union of sets A and B is denoted by A ∪ B, and is the set of all those elements which belong to A or to B (or to both). i.e A={1,2,3} and B={3,4,5}

AuB={1,2,3,4,5} (Think poker all in)

AuB is the SET of all X'S SUCH that X is an ELEMENT

of A or X is an ELEMENT of B

A ∪ B = {x | x ∈ A or x ∈ B}.

“if x ∈ A ∪ B, then x ∈ A or x ∈ B”, and

“if x ∈ A or x ∈ B, then x ∈ A ∪ B”.

Combined stated of mother Union below

"iff" = if and only if -> is what it means

“x ∈ A ∪ B iff x ∈ A or x ∈ B”.

	Created by Brendon Barends over 7 years ago

Descrete Mathematics for explaining Sets

Introduction to Sets