\usepackage{amsthm,amssymb,amsmath}
\usepackage[top=20mm, bottom=15mm, left=20mm, right=20mm]{geometry}
%\usepackage{calc}
\usepackage{color,amsmath}
%\usepackage{graphicx}
%\usepackage{subfigure}
%\usepackage{framed} 
\usepackage[pagebackref=false,colorlinks,linkcolor=black,citecolor=black]{hyperref}
\usepackage[nottoc]{tocbibind}
\usepackage{makeidx}
\makeindex
%%%%%%%%%%%
\usepackage{fancyhdr}
\renewcommand{\chaptermark}[1]{\markboth{#1}{}}
\fancypagestyle{headings}{\renewcommand{\headrulewidth}{0.5pt}}
\fancyhead[LE,RO]{\bfseries\thepage}
\fancyhead[LO]{\bfseries\rightmark}
\fancyhead[RE]{\bfseries\leftmark}
\fancyfoot[C]{}
%%%%%%%%%%%%%%%%%%%%%%%%%%%
\renewcommand\proofname{\textbf{اثبات}}
\newcommand\persiangloss[2]{#1\dotfill\lr{#2}\\}
\newcommand\englishgloss[2]{#2\dotfill\lr{#1}\\}
\usepackage{graphicx}
\usepackage{xepersian}
%دستور زیر برای تعیین فونت متن فارسی می‌باشد.
\settextfont[Scale=0.8]{Persian Modern}
%دستور زیر برای تعیین فونت متن لاتین می‌باشد.
%\setlatintextfont{Linux Libertine}
%دستور زیر برای تعیین فونت اعداد می‌باشد.
\setdigitfont[Scale=1]{Persian Modern}
 \pagestyle{headings}
\baselineskip=0.3cm
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%%\pagestyle{headling}
%\thispagestyle{empty}
%\theoremstyle{definition}
%\newtheorem{definition}{تعریف}[section]
%\theoremstyle{theorem}
%\newtheorem{theorem}[definition]{قضیه}
%\newtheorem{lemma}[definition]{لم}
%\newtheorem{proposition}[definition]{گزاره}
%\newtheorem{corollary}[definition]{نتیجه}
%\newtheorem{remark}[definition]{ملاحظه}
%\theoremstyle{definition}
%\newtheorem{example}[definition]{مثال}
%\newtheorem{sol}[definition]{حل}
\newtheorem{definition}{تعریف}[section] 
\newtheorem{theorem}{قضیه}[section] 
\newtheorem{lemma}{لم}[section] 
\newtheorem{proposition}{گزاره}[section] 
\newtheorem{corollary}{نتیجه}[section] 
\newtheorem{remark}{ملاحظه}[section] 
\theoremstyle{definition} 
\newtheorem{example}{مثال}[section] 
\newtheorem{exercise}{تمرین}[section] 
   %%%%%%%%%%%%%%%%%%%%%%%%%%
   %%%%%%%%%%%%%%%%%%%%%%%%%%
\newcommand{\bt}{\begin{theorem}}
\newcommand{\et}{\end{theorem}}
\newcommand{\bl}{\begin{lemma}}
\newcommand{\el}{\end{lemma}}
\newcommand{\bc}{\begin{corollary}}
\newcommand{\ec}{\end{corollary}}
\newcommand{\bp}{\begin{proof}}
\newcommand{\ep}{\end{proof}}
\newcommand{\be}{\begin{example}}
\newcommand{\ee}{\end{example}}
\newcommand{\bs}{\begin{sol}}
\newcommand{\es}{\end{sol}}
\newcommand{\bd}{\begin{definition}}
\newcommand{\ed}{\end{definition}}
\newcommand{\bpr}{\begin{proposition}}
\newcommand{\epr}{\end{proposition}}
\newcommand{\br}{\begin{remark}}
\newcommand{\er}{\end{remark}}
\newcommand{\bx}{\begin{exercise}}
\newcommand{\ex}{\end{exercise}}
\newcommand{\no}{\nonumber}
\newcommand{\nt}{\noindent}
\newcommand{\h }{\hspace{0.01cm}}
\newcommand{\bq}{\begin{equation}}
\newcommand{\eq}{\end{equation}}
\newcommand{\blg}{\begin{align}}
\newcommand{\elg}{\end{align}}
\newcommand{\bqn}{\begin{equation*}}
\newcommand{\eqn}{\end{equation*}}
\newcommand{\blgn}{\begin{align*}}
\newcommand{\elgn}{\end{align*}}
\newcommand{\bcs}{\begin{cases}}
\newcommand{\ecs}{\end{cases}}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%