\documentclass{article}
\title{My First Document}
\author{Me}
\date{}

\bibliographystyle{plain}

\textheight 9in
\textwidth 6in
\renewcommand{\baselinestretch}{1.3}

\begin{document}
\maketitle

\begin{abstract}

Language processors analyse  programs to derive useful information about 
the programs.
Program analyses differ on the category of analysis,
the intended application of 
%information derived by an
analysis,  the time of performing 
\end{abstract}

\large


\section{First Section}
\label{sec:first}


Some analyses derive {\sffamily  \itshape \bfseries structural} information about a program 
which is based on the structure alone. Others derive {\em semantic\/} information
which transcends program structures.
It follows that a semantic analysis must necessarily be either 
preceded by or accompanied by
a structural analysis to construct a program representation on which semantic analysis
can be performed. Scanning and parsing are the classical examples of 
structural analysis while type analysis is the classical example of semantic
analysis.\footnote{This is a footnote}
%
%This is a comment.
%
\subsection{This is a subsection}
\subsubsection{This is a subsection}
\subsubsection*{This is a subsubsection}

\begin{itemize}
\item 
Structural : Constructing or analysing program representations as graphs
\end{itemize}

\section{Second Section}
As shown in the section \ref{sec:first} ...


This is a table.

\begin{table}[t]
\begin{center}
\begin{tabular}{|c|c|r|}
\hline
This & \multicolumn{2}{c|}{is a}  \\ \cline{2-3}
This & is & another row  \\
\hline 
\end{tabular}
\end{center}
\caption{My first Figure}
\label{tab:first}
\end{table}

THis is a line that follows table \ref{tab:first}.

As shown in \cite{NiNi92wiley} it follows that

\appendix
\section{Rules}

\nocite{Nie83indiaH}

\bibliography{sample}
\end{document}

