# Fractional part of a number

A function defined for all real numbers $x$ and equal to the difference between $x$ and the integral part (entier) $[x]$ of the number $x$. It is usually denoted by $\{x\}$. Thus, $\{1.03\}=0.03$; $\{-1.25\}=0.75$; $\{\pi\}=0.1415926535\dots$.