# Polyglossia and equations numbers [duplicate]

I'm a little ashamed but I seem as in the first step of Latex... In this example, the parenthesis of the equation number are inversed. Why? How I can I obtain the good numbering? Thanks.

I give a minimal example. The simple file

\documentclass[11pt]{book}

\usepackage{amssymb}
\usepackage{amsmath}

\usepackage{polyglossia}

\setmainlanguage{english}
\setotherlanguage{arabic}

\begin{document}
A sample
$$1+1=2$$
\end{document}


It's compilation gives