+% colors
+\newrgbcolor{hb}{0.75 0.77 0.89}
+\newrgbcolor{lbb}{0.75 0.8 0.88}
+\newrgbcolor{lachs}{1.0 .93 .81}
+
+% roman numbers
+\newcommand{\RM}[1]{\MakeUppercase{\romannumeral #1{}}}
+
+% vectors are simply represented by bold font characters
+\renewcommand{\vec}[1]{{\bf #1{}}}
+
+
+\newtheorem{theorem}{Theorem}[section]
+\newtheorem{lemma}[theorem]{Lemma}
+\newtheorem{proposition}[theorem]{Proposition}
+\newtheorem{corollary}[theorem]{Corollary}
+
+\newenvironment{proof}[1][Proof]{\begin{trivlist}
+\item[\hskip \labelsep {\bfseries #1}]}{\end{trivlist}}
+\newenvironment{definition}[1][Definition]{\begin{trivlist}
+\item[\hskip \labelsep {\bfseries #1}]}{\end{trivlist}}
+\newenvironment{example}[1][Example]{\begin{trivlist}
+\item[\hskip \labelsep {\bfseries #1}]}{\end{trivlist}}
+\newenvironment{remark}[1][Remark]{\begin{trivlist}
+\item[\hskip \labelsep {\bfseries #1}]}{\end{trivlist}}
+
+\newcommand{\qed}{\nobreak \ifvmode \relax \else
+\ifdim\lastskip<1.5em \hskip-\lastskip
+\hskip1.5em plus0em minus0.5em \fi \nobreak
+\vrule height0.75em width0.5em depth0.25em\fi}
+
+% author & title