\documentclass{jac}

%% read in additional TeX-packages or personal macros here:
%% e.g. \usepackage{xy}
% \usepackage{url}

%% define non-standard environments here, for example
\theoremstyle{plain}\newtheorem{satz}[thm]{Satz}
\def\eg{{\em e.g.}}
\def\cf{{\em cf.}}

%% due to the dependence on amsart.cls, \begin{document} has to occur
%% BEFORE the title and author information:
\begin{document}

% \title[short title]{title}
\title[Using jac.cls]{How to use jac.cls}

% \author[ref]{Short author}{Author}
\author[lab1]{Author A}{A. Uthor}
% \address[ref]{Address of authors with ref as reference}
\address[lab1]{Address 1, this is the address of A. Uthor's and C.
Uthot's institution
  \newline Their address uses several lines}  %required
\email{a.uthor@institute.sw}  %optional
\email[C. Uthot]{best.chos.univ@labo.ti} %optional
\urladdr{http://www.institute.sw}  %optional

\author[lab2]{Author B}{U. Athor}
\address[lab2]{address 2, of U. Athor's institution}	%optional
\email{u.athor@organization.ws}  %optional
\urladdr{http://www.organization.ws}  %optional

\author[lab1]{Author C}{C. Uthot}

\thanks{Thanks: \url{jac.cls} and this sample file are derived from
the files \url{stacs.cls} and  \url{stacs-smp.tex} with kind consent
of their authors.} %optional

%% mandatory lists of keywords and classifications:
\keywords{MANDATORY list of keywords}
\subjclass{PREFERRED list of ACM classifications}
% \titlecomment{OPTIONAL comment concerning the title, \eg, if a variant
% or an extended abstract of the paper has appeared elsewehere}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%% the abstract has to PRECEDE the command \maketitle:
%% be sure not to issue the \maketitle command twice!

\begin{abstract}
  \noindent The abstract must precede the maketitle command.  Be sure
  not to issue the maketitle command twice!  Preferably, the abstract
  should consist of plain text, in one paragraph, 
  without mathematical formul\ae, and
  without explicit references using \url{cite}.
\end{abstract}

\maketitle


%% start the paper here:
\section*{Introduction}\label{S:one}

It is usually a good idea to have an introduction.  This is a good
place to employ mathematical notation and give references, as opposed
to the abstract.  It is up to the authors to decide, whether to assign
a section number to the introduction or not.
  
It is recommended that authors use the sample file \url{jac-smp.tex}
as a template for their paper, as it contains additional indications,
more precise than can be spelled out in this text (\textit{e.g.}
placement of author and title indications, introduction of the
authors' favorite packages and commands, etc).


\section{Authors and other title issues}

The title command of this file has the following form,
\begin{verbatim}
    \title[Using jac.cls]{How to use jac.cls}
\end{verbatim}    
and it determines both the title and the running title (on top of 
odd-numbered pages except the title page). If the running title argument 
(between square brackets) is omitted, then the title is used as a 
running title.

The author command has the following form,
\begin{verbatim}
  \author[ref]{Short author}{Author}
\end{verbatim}
% 
The \url{ref} argument is optional and is used to associate author and
address. It should be a single word. The second argument is used in the
running head on even-numbered pages. It can be left blank (as in 
\url{{}}).

The address command has the following syntax,
\begin{verbatim}
  \address[ref]{Address of authors with ref as reference}
\end{verbatim}

This paper has three authors, two of which come from the same
institution. We used the following commands:

\begin{verbatim}
  \author[lab1]{Author A}{A. Uthor}
  \address[lab1]{Address 1, this is the address of A. Uthor's and C.
  Uthot's institution
    \newline Their address uses several lines}  %required
  \email{a.uthor@institute.sw}  %optional
  \email[C. Uthot]{best.chos.univ@labo.ti} %optional
  \urladdr{http://www.institute.sw}  %optional
  
  \author[lab2]{Author B}{U. Athor}
  \address[lab2]{address 2, of U. Athor's institution}	%optional
  \email{u.athor@organization.ws}  %optional
  \urladdr{http://www.organization.ws}  %optional
  
  \author[lab1]{Author C}{C. Uthot}

  \thanks{Thanks: \url{jac.cls} and this sample file are derived
  from  the files \url{lmcs.cls} and  \url{lmcs-smp.cls}.} %optional

\end{verbatim}

We use the reference \url{lab1} to associate A. Uthor and C. Uthot
with address 1 and \url{lab2} to associate U. Athor with address 2.  A
single \url{\email} command can be used for authors sharing an
affiliation, as in \url{{a.uthor,c.uthot}@institution1.wh}.  It is
also possible to associate an email address with each author, as in
this file, thanks to an optional argument between square brackets.

Only the addresses of the authors are mandatory, all other fields
are optional.  It is however recommended to give the email address of
at least one of the authors.
% 
It is possible to include a \url{\thanks} field with each author. The 
content of these fields will appear in the footnote area of the page, 
but it will not carry a reference to this or that author. It may make 
sense to include all the grant numbers and other institutional 
acknowledgments within a single \url{\thanks} field.

In case of a single author, the situation is of course simplified:
\begin{verbatim}
  \author{Author}{Name of Author}
  \address{address of author}
  \email{author@inst.ti} %optional
  \urladdr{http://www.inst.ti} %optional
  \thanks{Optional} %optional
\end{verbatim}

\section{Use of  Definitions, Theorems, etc.}

  Let us test a few commands.

\subsection{First Subsection}

This is a test of subsectioning.

\subsection{On statements}

Let us now define something.

\begin{defi}\label{D:first}
  Blah
\end{defi}

Please use the supplied proclamation environments (as well as LaTeX's
cross-referencing facilities), or extend them in the spirit of the
given ones, if necessary (\cf, Satz \ref{T:big} below).  Refrain from
replacing our proclamation macros by your own constructs, especially
do not change the numbering scheme: all proclamations are to be
numbered consecutively, within each section.
  
The following theorem-like environments are available.
  
\begin{itemize}
      \item \texttt{thm} or \texttt{theorem}\qquad  Theorem
      \item \texttt{cor} or \texttt{corollary} \qquad  Corollary
      \item \texttt{lem} or \texttt{lemma} \qquad  Lemma
      \item \texttt{prop} or \texttt{proposition} \qquad  Proposition
      \item \texttt{asm} or \texttt{assumption} \qquad  Assumption
\end{itemize}
and
\begin{itemize}
      \item \texttt{defi} or \texttt{definition} \qquad  Definition
      \item \texttt{rem} or \texttt{remark} \qquad  Remark
      \item \texttt{rems} or \texttt{remarks} \qquad Remarks (intended
      for use with itemized remarks)
      \item \texttt{exa} or \texttt{example} \qquad  Example
      \item \texttt{exas} or \texttt{examples} \qquad Examples
      (intended for use with itemized examples)
      \item \texttt{conj} or \texttt{conjecture} \qquad  Conjecture
      \item \texttt{prob} or \texttt{problem} \qquad  Problem
      \item \texttt{oprob} \qquad  Open Problem
      \item \texttt{algo} or \texttt{algorithm} \qquad  Algorithm
      \item \texttt{obs} or \texttt{observation} \qquad  Observation
\end{itemize}      

If you require additional environments, you can add them before
\url{\begin{document}} by means of

\begin{verbatim}
    \theoremstyle{plain}\newtheorem{env}[thm]{Environment}
\end{verbatim}

  or
  
\begin{verbatim}
    \theoremstyle{definition}\newtheorem{env}[thm]{Environment}
\end{verbatim}
% 
In the first case the font within the new environment will be
italicised.


\subsection{On proofs}

Proofs start with a \url{\proof} command, and end with a \url{\qed}
command. The latter produces the end-of-proof box.
    
\begin{satz}\label{T:big}
    This is a sample for a proclamation environment that can be added
    along with your personal macros, in case the supplied environments
    are insufficient.
\end{satz}

\proof
It is possible to start your proof with another text than ``Proof.''
The proof of Theorem~\ref{T:m} below starts with
\begin{verbatim}
    \proof[Proof of Theorem~\ref{T:m}]
\end{verbatim}    
% 
If the proof ends with an itemized or enumerated environment (as in
Theorem~\ref{T:m}), the \url{\qed} command has to occur BEFORE the
\url{\end{itemize}} or \url{\end{enumerate}} command to ensure proper
placement of the box.\qed

Consequently, we have

\begin{cor}\label{C:big}
  Blah.  If no proof is given, an end-of-proof box should conclude a
  proclamation (Theorem, Proposition, Lemma, Corollary). If the 
  statement ends with an itemized or enumerated environment, the same 
  recommendation as above holds, concerning the placement of the 
  \url{\qed} command.\qed
\end{cor}


When proclamations or proofs start with a list environment (itemize,
enumerate) without preceding text, the default is that the first item
of the list environment appears on the same line as the proclamation
(or proof) title, which results in poor alignment of the different
list items.  This can be prevented by inserting \url{\hfill} before
the \url{\begin{itemize}} or the \url{\begin{enumerate}} command.

\begin{thm}\label{T:m}\hfill  %% \hfill pushes the first item to a new line
\begin{itemize}
\item[(0)]
  Issuing an \url{\hfill} command before the beginning of the list
  environment will push the first item to a new line, like in this
  case.
\item[(1)]
  blah.
\end{itemize}
\end{thm}

\proof[Proof of Theorem~\ref{T:m}]\hfill  %% \hfill pushes the first item to a new line
\begin{itemize}
\item[(0)]
  The same behaviour occurs in proofs; to start the first item on a
  new line, an explicit \url{\hfill} command is necessary.
\item[(1)]
  blah, according to \cite{mib}.\qed
\end{itemize}

\noindent We recommend using this variant since it produces a more
orderly output.


\subsection{Bibliography style}

\subsubsection{One style}

In order to produce a bibliography with alphanumeric keys, as in this 
file, you may use a \url{\bibitem} command of the form
\begin{verbatim}
    \bibitem[Kos97]{mib} J{\"u}rgen Koslowski.  Monads and interpolads
    in bicategories.  {\em Theory Appl.  Categ.}, 3(8):182--212, 1997.
\end{verbatim}

\subsubsection{Or another}


If you wish instead to produce a bibliography with automatically 
numbered entries, simply omit the argument in square brackets as in
\begin{verbatim}
    \bibitem{mib} J{\"u}rgen Koslowski.  Monads and interpolads in
    bicategories.  {\em Theory Appl.  Categ.}, 3(8):182--212, 1997.
\end{verbatim}

\section*{Acknowledgement}
  The authors wish to acknowledge fruitful discussions with A and B.
%   
  Acknowledgements should be placed in a non-numbered section 
  \url{\section*{Acknowledgement}}.

%% in general the use of bibtex is encouraged

\begin{thebibliography}{Kos97}

    \bibitem[Kos97]{mib}
    J{\"u}rgen Koslowski.
    \newblock Monads and interpolads in bicategories.
    \newblock {\em Theory Appl.  Categ.}, 3(8):182--212, 1997.

\end{thebibliography}

\newpage\appendix
\section{}

  Are you sure you want an appendix? If so, you might want to start 
  it on a new page, like this one.
  
  At any rate, remember that while appendices may be useful during 
  the refereeing process, they will not be part of the final 
  publication, which must be self-contained.

\end{document}
