mystyle.sty

\usepackage[headheight=14pt]{geometry}
% ---------------------------
% packages
% ---------------------------
% AMS math symbol
\usepackage{amsmath}
\usepackage{amsbsy}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amscd}
\usepackage{mathrsfs}
%\usepackage{mathptmx}       % selects Times Roman as basic font
\usepackage{algorithmic, algorithm}
\usepackage{bm}

% text fonts
\usepackage{txfonts}
%\usepackage{helvet}         % selects Helvetica as sans-serif font
%\usepackage{courier}        % selects Courier as typewriter font
\usepackage[latin1]{inputenc}


% 

% graphcis
\usepackage{graphicx}
\usepackage{subfigure} 

\usepackage{tikz}   
\usetikzlibrary{shapes,arrows,decorations.pathmorphing,backgrounds,positioning,fit,matrix,calc} 

% other tools
\usepackage{hyperref}
\usepackage{type1cm}       
%%\usepackage[normalem]{ulem}
\usepackage{soul}
%\usepackage{times}
\usepackage{url}
\usepackage{rotating} 
\usepackage{makeidx}
\makeindex             
\usepackage{multirow}
\usepackage{multicol}   
\usepackage{enumerate}
\usepackage{xspace}
\usepackage{comment} 
\usepackage{etoolbox}

%% 
% ---------------------------
% Formats
% ---------------------------
% head
\usepackage{titling}
\usepackage{fancyhdr}
\pagestyle{fancy}
\lhead{\leftmark}       % Chapter name on the top left.
\rhead{\theauthor}      % Author name on the top right.
% page
\pagenumbering{arabic}

% ---------------------------
% Theorems etc.
% ---------------------------
\ifcsmacro{theorem}{}{
\newtheorem{theorem}{Theorem}[section]
}
\ifcsmacro{lemma}{}{
\newtheorem{lemma}[theorem]{Lemma}
}
\ifcsmacro{corollary}{}{
\newtheorem{corollary}[theorem]{Corollary}
}
\ifcsmacro{proposition}{}{
\newtheorem{proposition}[theorem]{Proposition}
}
%\ifcsmacro{assumption}{}{
%\newtheorem{assumption}[theorem]{Assumption}
%}
\newtheorem{assumption}{Assumption}
\renewcommand\theassumption{A\arabic{assumption}}
%\newtheorem{consequence}[equation]{Consequence}
%\newtheorem{conclusion}[equation]{Conclusion}
\newcommand{\Remark}{\noindent{\bf Remark.~}}
%\newtheorem{remark}[theorem]{Remark}
%\newtheorem{definition}[theorem]{Definition}
%\newtheorem{exercise}[theorem]{Exercise}
%\newtheorem{example}[theorem]{Example}


\def\proof{\par{\it Proof}. \ignorespaces}
\def\endproof{{\ \vbox{\hrule\hbox{\vrule
        height1.3ex\hskip0.8ex\vrule}\hrule}}\par}
        
% ---------------------------
% Chapter and sections
% ---------------------------
\let\oldchapter\chapter
\def\chapter{%
  \setcounter{exercise}{0}%
  \oldchapter
}