Set Theory - Bijection function (One-to-one relationship)

A Bijection is a mathematical / set function between the elements of two sets (ie binary function) where

• each element of one set is paired with exactly one element of the other set,
• each element of the other set is paired with exactly one element of the first set.
• there are no unpaired elements

This function is also known as:

• the one-to-one relationship
• or invertible function

• A bijection (Ref

• Not a bijection

A function f: R → R is bijective if and only if its graph meets every horizontal and vertical line exactly once.

• Bijection