Is there well known or common notation for an indicator-like function that tells if $a$ divides $b$? Something like the Kronecker delta, but for divisibility?
A function like:
$\begin{align} \mathcal{I}:\mathbb{Z}^2 \mapsto \{0,1\} \text{, where } \mathcal{I}(a,b)=\begin{cases} 1, & \text{if } a\mid b\\ 0, & \text{if } a \nmid b \end{cases} \end{align}$
Or is there a better way to think about this function?