\documentclass[12pt,a4paper]{report}

\usepackage{amsthm,amssymb,amsmath}  

\setlatintextfont[Scale=.9]{Arial}
\setdigitfont[Scale=1]{XB Zar}

                      
                      \makeindex  %نمایه
                      
                      
                      
                      \pagestyle{fancy}
                      \cfoot{}
                      \lhead{\thepage}
                      
                      
                          \input{mygloss}
                          
                          
                          \begin{document}
                          	
                          	\gls*{Union}	:  اگر 
                          	$ A$
                          
                          
                        
                          	\gls*{Intersection}: اگر 
                          	$ A$
                          	
                          	
                          
                          \printglossary
                          \printabbreviation
                          \printindex    %
                          	
\end{document}