# Math Help - authors' addresses+abstract+subject classification+keywords, paragraph numbering

1. ## authors' addresses+abstract+subject classification+keywords, paragraph numbering

i have 2 problems here.

1.
how to put the authors' addresses right after the authors' name?
also, to label the authors name by 1,2,3,....
after the addresses, i need to put "abstract", then "subject classification", finally "keywords".
All "authors' addresses+abstract+subject classification+keywords" must be before the first section "Introduction".

2.
This is a part of my output:

2. HNN extensions
Definition 1.

Definition 2.

Lemma 1.

Theorem 1.

How to make it become:

2. HNN extensions (each section allign to the left)

Definition 2.1.

Definition 2.2.

Lemma 2.1.

Theorem 2.1.

This is my tex:
\documentclass[12pt]{amsart}
\usepackage{amssymb, latexsym}
\theoremstyle{plain}
\newtheorem{theorem}{Theorem}
\newtheorem{lemma}{Lemma}
\newtheorem{proposition}{Proposition}
\newtheorem{definition}{Definition}
\newtheorem{corollary}{Corollary}
\newtheorem{notation}{Notation}
\numberwithin{equation}{section}
\begin{document}
\title{}
\author{}
\email{}

\author{}
\email{}

\author{}
\email{}

\keywords{}
\subjclass[2000]{Primary: ; Secondary }
\date{November 2010}

\begin{abstract}
In this note, we show that
\end{abstract}

\maketitle

\section{\bf Introduction}

\section{\bf HNN extensions}

\begin{definition}
\end{definition}

\begin{definition}
\end{definition}

\begin{lemma}
\end{lemma}

\begin{theorem}
\end{theorem}

2. Originally Posted by deniselim17
This is a part of my output:

2. HNN extensions
Definition 1.

Definition 2.

Lemma 1.

Theorem 1.

How to make it become:

2. HNN extensions (each section align to the left)

Definition 2.1.

Definition 2.2.

Lemma 2.1.

Theorem 2.1.
To get numbers of theorems etc. to include the section number, you need to do two things: (1) add a command \renewcommand{\thetheorem}{\thesection.\arabic{the orem}, to prefix the theorem number with the section number; (2) add another command \numberwithin{theorem}{section}, to ensure that the theorem numbers start again at 1 in each new section. I have done this for "theorem", "lemma" and "definition" (in red, below). You will need to do the same for any other theorem-type environments such as "corollary" and "notation".

To make section headings left-aligned is more complicated. I think that you will have to redefine the \section command, as in green below. While doing that, I incorporated a command to make the section titles boldface, so you don't need to add the \bf command for each individual section title.

\documentclass[12pt]{amsart}
\usepackage{amssymb, latexsym}
\theoremstyle{plain}
\newtheorem{theorem}{Theorem}
\newtheorem{lemma}{Lemma}
\newtheorem{proposition}{Proposition}
\newtheorem{definition}{Definition}
\newtheorem{corollary}{Corollary}
\newtheorem{notation}{Notation}
\numberwithin{equation}{section}

\renewcommand{\thetheorem}{\thesection.\arabic{the orem}}
\numberwithin{theorem}{section}
\renewcommand{\thelemma}{\thesection.\arabic{lemma }}
\numberwithin{lemma}{section}
\renewcommand{\thedefinition}{\thesection.\arabic{ definition}}
\numberwithin{definition}{section}

\makeatletter
\renewcommand{\section}{\@startsection
{section}{1}{0pt}{\baselineskip}{\baselineskip}{\n ormalfont\normalsize\bfseries}}
\makeatother

\begin{document}

\title{}
\author{}
\email{}

\author{}
\email{}

\author{}
\email{}

\keywords{}
\subjclass[2000]{Primary: ; Secondary }
\date{November 2010}

\begin{abstract}
In this note, we show that
\end{abstract}

\maketitle

\section{Introduction}

\section{HNN extensions}

\begin{definition}
\end{definition}

\begin{definition}
\end{definition}

\begin{lemma}
\end{lemma}

\begin{theorem}
\end{theorem}

\section{Next}

\begin{definition}
\end{definition}

\begin{definition}
\end{definition}

\begin{lemma}
\end{lemma}

\begin{theorem}
\end{theorem}

\end{document}

Edit. The MHF editor has introduced some unwanted spaces ("the orem", "/n ormalfont") that I can't get rid of. They ought not to be there.