Let A be any non-empty set. Then, prove that the identity function on set A is a bijection.

Explanation

An identity function, also called an identity relation is a function that always returns the value
that was used as its argument,
That is, when f is the identity function, the equality
`f(X) = X` is true for all values of `X`


Similarly if M is a set, the identity function f on M is
defined to be a function with M as its domain and codomain, satisfying

`f(X) = X` for all elements `X `


Thus,the identity function on M is clearly an injective function
as well as a surjective function, so it is bijective