Take the 2-minute tour ×
TeX - LaTeX Stack Exchange is a question and answer site for users of TeX, LaTeX, ConTeXt, and related typesetting systems. It's 100% free, no registration required.

I am working on a large, multi-chapter document using the memoir class. I have sections, subsections, and subsubsections within each chapter, and within the subsubsections are theorems, lemmas, propositions, etc.

I have all of the theorems, propositions, etc sharing a single counter, which is subordinate to the subsection. So currently things look like this:

Chapter 1

Section 1.1

Subsection 1.1.1

Subsubsection 1.1.1.1

Theorem 1.1.1.1

Subsubsection 1.1.1.2

Definition 1.1.1.2

Remark 1.1.1.3

Subsubsection 1.1.1.3

I want the numbering of theorems, propositions, etc to use the same counter as the subsubsections, so that things would look like this instead:

Chapter 1

Section 1.1

Subsection 1.1.1

Subsubsection 1.1.1.1

Theorem 1.1.1.2

Subsubsection 1.1.1.3

Definition 1.1.1.4

Remark 1.1.1.5

Subsubsection 1.1.1.6

I would prefer to use amsthm, but I'm open to using other packages if necessary.

Bonus points: how to get the equation numbering to use the same counter?

share|improve this question
add comment

1 Answer 1

up vote 4 down vote accepted

Use the first optional argument for \newtheorem:

\documentclass{book}
\usepackage{amsthm}

\newtheorem{theo}[subsubsection]{Theorem}
\newtheorem{defi}[subsubsection]{Definition}
\setcounter{secnumdepth}{3}

\begin{document}

\chapter{Test Chapter}
\section{Test Section}
\subsection{Test Subsection}
\subsubsection{Test Subsubsection}
\begin{theo}
test.
\end{theo}
\subsubsection{Test Subsubsection}
\begin{theo}
test.
\end{theo}
\begin{defi}
test.
\end{defi}
\subsubsection{Test Subsubsection}

\end{document}

enter image description here

I think this numbering schema can result hard to follow for readers (among other things, what if, for example, there's a theorem or a definition before a subsubsection is created?).

For the bonus point (and to make things even harder for the reader):

\documentclass{book}
\usepackage{amsthm}
\usepackage{amsmath}
\usepackage{etoolbox}
\numberwithin{equation}{subsection}

\newtheorem{theo}[subsubsection]{Theorem}
\newtheorem{defi}[subsubsection]{Definition}
\setcounter{secnumdepth}{3}

\AtBeginEnvironment{equation}{\setcounter{equation}{\value{subsubsection}}}{}{}{}
\AtEndEnvironment{equation}{\stepcounter{subsubsection}}{}{}{}

\begin{document}

\chapter{Test Chapter}
\section{Test Section}
\subsection{Test Subsection}
\subsubsection{Test Subsubsection}
\begin{theo}
test.
\end{theo}
\subsubsection{Test Subsubsection}
\begin{theo}
test.
\end{theo}
\begin{defi}
test.
\end{defi}
\begin{equation}
a=b.
\end{equation}
\subsubsection{Test Subsubsection}
\begin{equation}
c=d.
\end{equation}

\end{document}

enter image description here

I would rather use a simpler numbering schema:

\documentclass{book}
\usepackage{amsthm}
\usepackage{amsmath}

\newtheorem{theo}{Theorem}[chapter]
\newtheorem{defi}[theo]{Definition}
\newtheorem{prop}[theo]{Proposition}
\setcounter{secnumdepth}{3}

\begin{document}
...
\end{document}
share|improve this answer
    
Thank you for your answer. Could you please explain why you think this makes it harder to read? To me it seems simpler: now there is only one thing numbered 1.1.1.1, whereas before there could have been more. –  MTS Mar 27 '13 at 2:53
    
So, I guess another question is: what numbering scheme do you think makes the most sense in a situation where one has sectioning units ranging from chapters to subsubsections? –  MTS Mar 27 '13 at 2:56
    
@MTS I would simply opt for subordinating the counters to the chapter counter, as in my updated answer. –  Gonzalo Medina Mar 27 '13 at 3:04
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.