# Greatest integer function

The greatest integer function of $x$ is sometimes denoted $[x]$. However, the square brace notation $[]$ is also used in a number of other contexts and should not always be construed as meaning the greatest integer function.
The greatest integer function is related to the fractional part function (sometimes denoted $\{ \}$) as follows: for any $x \in \R$, we have:
$\! x = [x] + \{ x \}$