\NeedsTeXFormat{LaTeX2e}
\ProvidesClass{eurocg09}

%-------------------- This is based on the article class ----------------

\PassOptionsToClass{twocolumn}{article}
\PassOptionsToClass{twoside}{article}
\PassOptionsToClass{a4paper}{article}

\LoadClass{article}

\RequirePackage{theorem,graphicx,amssymb,amsmath}

%------------------ Defining the most common environments ---------------

\theorembodyfont{\slshape}

\newtheorem{theorem}{Theorem}
\newtheorem{lemma}[theorem]{Lemma}
\newtheorem{cor}[theorem]{Corollary}
\newtheorem{prop}[theorem]{Proposition}
\newtheorem{invar}{Invariant}
\newtheorem{obs}{Observation}
\newtheorem{conj}{Conjecture}
\newtheorem{defini}{Definition}

\def\QED{\ensuremath{{\square}}}
\def\markatright#1{\leavevmode\unskip\nobreak\quad\hspace*{\fill}{#1}}
\newenvironment{proof}
  {\begin{trivlist}\item[\hskip\labelsep{\bf Proof.}]}
  {\markatright{\QED}\end{trivlist}}

%------------------------------------------------------------------------

\setlength{\textheight}{9.50in}
\setlength{\textwidth}{6.75in}
\setlength{\topmargin}{-0.40in}
\setlength{\oddsidemargin}{-0.125in}
\setlength{\evensidemargin}{-0.375in}
\setlength{\columnsep}{2pc}
\setlength{\headheight}{0.200in}
\setlength{\headsep}{0.4in}
\setlength{\footskip}{0.450in}
\setlength{\parindent}{1em}
\flushbottom

\font\tensfb = cmssbx10
\newcommand{\@titlestyle}{\normalsize\tensfb}

\renewcommand{\@maketitle}{%
  \newpage
  \null
  \vskip 2em%
  \begin{center}%
    \let \footnote \thanks
    {\vspace{-.2in}\Large\sffamily\bfseries \@title \par}%
    \vskip 1.5em%
    {\normalsize
      \lineskip .5em%
      \begin{tabular}[t]{c}%
        \@author
      \end{tabular}\par}%
    \vskip 1em%
    {\large \@date}%
  \end{center}%
  \par
  \vskip 3em}
  
\renewenvironment{theindex}
               {\if@twocolumn
                  \@restonecolfalse
                \else
                  \@restonecoltrue
                \fi
                \columnseprule \z@
                \columnsep 35\p@
                \twocolumn[\section*{\indexname}]%
                \@mkboth{\MakeUppercase\indexname}%
                        {\MakeUppercase\indexname}%
                \thispagestyle{fancy}\parindent\z@
                \parskip\z@ \@plus .3\p@\relax
                \let\item\@idxitem}
               {\if@restonecol\onecolumn\else\clearpage\fi}  

\renewcommand\section{\@startsection {section}{1}{\z@}{-3.5ex plus
    -1ex minus -.2ex}{2.3ex plus .2ex}{\@titlestyle}}
\renewcommand\subsection{\@startsection{subsection}{2}{\z@}{-3.25ex
    plus -1ex minus -.2ex}{1.5ex plus .2ex}{\@titlestyle}}
\renewcommand\subsubsection{\@startsection{subsubsection}{3}{\z@}{-3.25ex
    plus -1ex minus -.2ex}{1.5ex plus .2ex}{\@titlestyle}}
\renewcommand\paragraph{\@startsection {paragraph}{4}{\z@}{3.25ex plus
    1ex minus .2ex}{-1em}{\@titlestyle}}
\renewcommand\subparagraph{\@startsection
  {subparagraph}{4}{\parindent}{3.25ex plus 1ex minus
    .2ex}{-1em}{\@titlestyle}}

\renewcommand\abstract{\if@twocolumn
\section*{Abstract}
\else \small
\begin{center}
{\sffamily\bfseries Abstract\vspace{-.5em}\vspace{0pt}}
\end{center}
\quotation
\fi}

\def\endabstract{\if@twocolumn\else\endquotation\fi}

\date{}

\renewcommand{\textfraction}{0.05}
\renewcommand{\bottomfraction}{0.95}
\renewcommand{\topfraction}{0.95}
\renewcommand{\dbltopfraction}{0.95}
\renewcommand{\dblfloatpagefraction}{0.8}
\setcounter{topnumber}{3}

\newcommand{\l@day}{\@dottedtocline{1}{0em}{0em}}
\newcommand{\l@session}{\@dottedtocline{1}{0em}{1in}}
\newcommand{\l@algorithm}{\@dottedtocline{1}{0em}{1in}}
\renewcommand{\@dotsep}{500}