[Tex/LaTex] Numbering theorems as subsubsections

numberingsectioningtheorems

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?

Best Answer

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}

Related Solutions

[Tex/LaTex] Theorem/Definition/Lemma problem — Numbering

Similar to the solution at this question and section 3 of the amsthm documentation:

enter image description here

\documentclass[11pt,a4paper]{report}
\usepackage{amsthm}

\theoremstyle{plain}
\newtheorem{thm}{Theorem}[chapter] % reset theorem numbering for each chapter

\theoremstyle{definition}
\newtheorem{defn}[thm]{Definition} % definition numbers are dependent on theorem numbers
\newtheorem{exmp}[thm]{Example} % same for example numbers

\newcommand{\chaptercontent}{
\section{Basics}
\begin{defn}Here is a new definition.\end{defn}
\begin{thm}Here is a new theorem.\end{thm}
\begin{thm}Here is a new theorem.\end{thm}
\begin{exmp}Here is a good example.\end{exmp}
\subsection{Some tips}
\begin{defn}Here is a new definition.\end{defn}
\section{Advanced stuff}
\begin{defn}Here is a new definition.\end{defn}
\subsection{Warnings}
\begin{defn}Here is a new definition.\end{defn}
}

\begin{document}
\tableofcontents
\part{Addition and Subtraction}
\chapter{Addition} \chaptercontent
\chapter{Subtraction} \chaptercontent
\part{Multiplication and Division}
\chapter{Multiplication} \chaptercontent
\chapter{Division} \chaptercontent
\end{document}

[Tex/LaTex] Common numbering with ntheorem

From your code, it seems that you want each of the theorem-like environments to inherit the subsection counter. As such, I have used

\newcounter{dummy} 
\numberwithin{dummy}{subsection}

in the below.

Note that you can use

\newtheorem{example}[dummy]{Example}

which tells the newtheorem command to make the example counter inherit the dummy counter, but not

\newtheorem{example}{Example}[dummy][subsection]

as this is undefined.

screenshot

Here's the complete MWE:

\documentclass{article}

\usepackage{amsmath,amssymb}
\usepackage[thmmarks]{ntheorem}

\newcounter{dummy}
\numberwithin{dummy}{subsection}

\theoremprework{\setlength
\theorempreskipamount{10 pt}\setlength\theorempostskipamount{10 pt}}

\theoremstyle{plain}
\theorembodyfont{\upshape}
\theoremsymbol{\ensuremath{\clubsuit}}
\theoremseparator{:}
\newtheorem{example}[dummy]{Example}

\theoremstyle{plain}
\theorembodyfont{\upshape}
\theoremsymbol{\ensuremath{\blacklozenge}}
\theoremseparator{:}
\newtheorem{remark}[dummy]{Remark}

\theoremprework{\setlength\theorempreskipamount{10 pt}}

\theoremstyle{plain}
\theorembodyfont{\slshape}
\theoremsymbol{}
\theoremseparator{:}
\newtheorem{theorem}[dummy]{Theorem}

\theoremstyle{plain}
\theorembodyfont{\slshape}
\theoremsymbol{}
\theoremseparator{:}
\newtheorem{prop}[dummy]{Proposition}


\theoremstyle{plain}
\theoremheaderfont{\upshape \bfseries}
\theorembodyfont{\slshape}
\theoremsymbol{}
\theoremseparator{:}
\newtheorem{corollary}[dummy]{Corollary}

\theoremstyle{plain}
\theoremheaderfont{\upshape \bfseries}
\theorembodyfont{\slshape}
\theoremsymbol{}
\theoremseparator{:}
\newtheorem{lemma}[dummy]{Lemma}

\begin{document}

\section{Section}
\subsection{SubSection}
\begin{theorem} Hey
\end{theorem}

\begin{lemma}I
\end{lemma}

\begin{prop}Just
\end{prop}

\begin{remark}Met
\end{remark}

\begin{example}You
\end{example}

\subsection{SubSection}
\begin{theorem} Hey
\end{theorem}

\begin{lemma}I
\end{lemma}

\begin{prop}Just
\end{prop}

\begin{remark}Met
\end{remark}

\begin{example}You
\end{example}
\end{document}

Best Answer

Related Solutions

[Tex/LaTex] Theorem/Definition/Lemma problem — Numbering

[Tex/LaTex] Common numbering with ntheorem

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