Bijection

One-to-one correspondence

In mathematics, a bijection, bijective function, or one-to-one correspondence is a function between two sets such that each element of the second set (the codomain) is the image of exactly one element of the first set (the domain). Given a function f : A → B {\displaystyle f:A\to B} , the image of an element a ∈ A {\displaystyle a\in A} is the element f ( a) ∈ B {\displaystyle f(a)\in B} in the codomain. The pre-image of an element b ∈ B {\displaystyle b\in B} is any element a ∈ A {\displaystyle a\in A} in the domain such that f ( a) = b {\displaystyle f(a)=b} .

From Wikipedia, under CC BY-SA. More on occurri.