\documentclass[openany,12pt]{report}

\usepackage{amsmath}
\usepackage{xepersian}

\begin{document}

\DefaultMathsDigits

\begin{align*}
&I_x:G\longrightarrow G\\
&I_x(g)=x^{-1}gx  \ \ \ \ \   \forall g\in G
\end{align*}

$A=\{1,2,\dots ,n\}$


 \end{document}


























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