# Numbering theorems in the left margin

My question is similar to this and this. I would like to have the theorem number in the left margin (0.6em spacing to the main text) and the Name 'Theorem' should be justified to the main text. The solution should made with the amsthmpackage, because I've made my very specific proof environment with \renewenvironment from amsthm.

\documentclass[12pt,a4paper]{article}
\usepackage[ngerman]{babel}
\usepackage{lipsum,lmodern,libertine}
\usepackage{amsmath,amsfonts,amssymb}
\usepackage{amsthm}
\newtheoremstyle{mystyle}
{\topsep}               %space above
{\topsep}               %space below
{}                      %bodyfont
{}                      %indent
{}                      %punctuation
\theoremstyle{mystyle}
\newtheorem{theorem}{Theorem}

\begin{document}
\lipsum[1]

\begin{theorem}
Let $f\colon [a,b]\to\mathbb{R}$ be continious and let $F$ be an antiderivative of $f$, then
\begin{align*}
\int_a^b f(x)\,\mathrm{d}x=F(b)-F(a).
\end{align*}
\end{theorem}

\end{document}


This looks like

But it should look like this (this was made with the ntheorem package):

-
Welcome to TeX.SX! You can have a look at our starter guide to familiarize yourself further with our format. – karlkoeller Jan 24 '14 at 19:11
Have you read this post: tex.stackexchange.com/q/59244/10898 – azetina Jan 24 '14 at 19:11

It sounds like you want the \llap command for left overlap

{\llap{#2 }#1 #3}              %theoremheadspec


Here's a complete MWE to play with.

% arara: pdflatex
\documentclass[12pt,a4paper]{article}
\usepackage{amsmath,amssymb}
\usepackage{lipsum}
\usepackage{amsthm}
\newtheoremstyle{mystyle}
{\topsep}               %space above
{\topsep}               %space below
{}                      %bodyfont
{}                      %indent
{}                      %punctuation
\theoremstyle{mystyle}
\newtheorem{theorem}{Theorem}

\begin{document}
\lipsum[1]

\begin{theorem}
Let $f\colon [a,b]\to\mathbb{R}$ be continious and let $F$ be an antiderivative of $f$, then
\begin{align*}
\int_a^b f(x)\,\mathrm{d}x=F(b)-F(a).
\end{align*}
\end{theorem}

\end{document}

-
No fair! You won me by a few seconds :-) – azetina Jan 24 '14 at 19:15
@azetina if it makes you feel better, that's happened to me a lot on the site :) – cmhughes Jan 24 '14 at 19:16
I could imagine. ;-) – azetina Jan 24 '14 at 19:17
Since the OP wants 0.6em I'd say \llap{#2\hspace{.6em}} – karlkoeller Jan 24 '14 at 19:20
@karlkoeller nice catch- thanks – cmhughes Jan 24 '14 at 21:35