Injective Function

up:: 020 MOC Mathematics

A function $f:X\to Y$ is said to be injective if it maps each point $x\in X$ to a different point $y\in Y$. That is,

$$\forall x\in X,\exists !y\in Y\mid f(x)=y$$

Note that, when restricted to its image $f(X)$, $f:X\to f(X)$ can be seen as a Bijective Function.