[Tex/LaTex] What symbol for primitive recursive cutoff minus

Question

I am using $\overset{.}{-}$ for the primitive recursive function between natural numbers such that $m\overset{.}{-}n$ is m minus n if m>=n and otherwise 0. Is there a better and more canonical alternative for a mathematical text?

Answer 1

A stack is an option. The vertical gap between the . and - is set with the argument that is currently {-1pt}.

\documentclass{article}
\usepackage{amsmath,stackengine}
\def\prf{\ensurestackMath{\mathbin{\stackengine{-1pt}{-}{.}{O}{c}{F}{F}{S}}}}
\begin{document}
$m \prf n$ is $m$ minus $n$ if $m\geq n$ and otherwise $0$.
\end{document}