Mapping/Bijective/Definition

Let ${\displaystyle {}M}$ and ${\displaystyle {}L}$ denote sets, and suppose that

${\displaystyle F\colon M\longrightarrow L,x\longmapsto F(x),}$

is a mapping. Then ${\displaystyle {}F}$ is called bijective if ${\displaystyle {}F}$ is injective as well as surjective.