[texhax] Typing out nPr (permutations)

[Philip G. Ratcliffe]

> Does anyone know of a macro in (AMS)LaTeX that has the symbol for nPr?

No, I don't think there is such a macro.

> I understand that \binom{n}{r} and its variants, but there 
> seems to be nothing for nPr.
> 
> The manual (and perhaps clumsy) way I've been using is
> 
> $^n P_r$

You can use the tensor package to get better spacing and alignment:

\documentclass{article}
\usepackage{tensor}
\newcommand\Perms[2]{\tensor[^{#2}]P{_{#1}}}
\begin{document}
$\Perms{n}{r}$
\end{document}

Cheers,  Phil