# Corollary counter in SVmono

When using the predefined Theorem and Corollary commands using the Springer template svmono, the theorem and corollary counters are different. How can I make the counters match? The desired effect is to have

Theorem 1.

Theorem 2.

Corollary 3.

Theorem 4.

The svmono class has its own method for defining theorem-like environments:

\spnewtheorem{<env>}{<label>}[<within>]{<label font>}{<body font>}


or

\spnewtheorem{<env>}[<counter>]{<label>}{<label font>}{<body font>}


The former syntax corresponds to \newtheorem{<env>}{<label>}[<within>], the latter to \newtheorem{<env>}[<counter>]{<label>}. There is also

\spnewtheorem*{<env>}{<label>}{<label font>}{<body font>}


for unnumbered environments.

The class predefines a theorem environment in one of these formats

1. \spnewtheorem{theorem}{Theorem}{\bfseries}{\itshape} is the default;

2. \spnewtheorem{theorem}{Theorem}[chapter]{\bfseries}{\itshape} if the envcountchap class option is specified;

3. \spnewtheorem{theorem}{Theorem}[section]{\bfseries}{\itshape} if the envcountsect class option is specified.

The class also predefines several environments:

\spn@wtheorem{case}{Case}{\itshape}{\rmfamily}
\spn@wtheorem{conjecture}{Conjecture}{\itshape}{\rmfamily}
\spn@wtheorem{corollary}{Corollary}{\bfseries}{\itshape}
\spn@wtheorem{definition}{Definition}{\bfseries}{\rmfamily}
\spn@wtheorem{example}{Example}{\itshape}{\rmfamily}
\spn@wtheorem{exercise}{Exercise}{\bfseries}{\rmfamily}
\spn@wtheorem{lemma}{Lemma}{\bfseries}{\itshape}
\spn@wtheorem{note}{Note}{\itshape}{\rmfamily}
\spn@wtheorem{problem}{Problem}{\bfseries}{\rmfamily}
\spn@wtheorem{property}{Property}{\itshape}{\rmfamily}
\spn@wtheorem{proposition}{Proposition}{\bfseries}{\itshape}
\spn@wtheorem{question}{Question}{\itshape}{\rmfamily}
\spn@wtheorem{solution}{Solution}{\bfseries}{\rmfamily}
\spn@wtheorem{remark}{Remark}{\itshape}{\rmfamily}


It uses internally \spn@wtheorem so that these definition can be adjusted according to another class option; if envcountsame is specified among the class options, all these environments will be subordinate to theorem.

There are also two predefined unnumbered environments:

\spnewtheorem*{claim}{Claim}{\itshape}{\rmfamily}
\spnewtheorem*{proof}{Proof}{\itshape}{\rmfamily}


## Example

\documentclass[
envcountsame,% all theorem-like environments are subordinate to theorem
envcountchap,% theorem is subordinate to chapter: Theorem <chap>.<theorem>'
%  envcountsect,% theorem is subordinate to section: Theorem <chap>.<section>.<theorem>'
]{svmono}
\usepackage{fix-cm}% or \usepackage{lmodern}
\usepackage[T1]{fontenc}

\begin{document}
\chapter{Title}
\section{Title}

\begin{lemma}
Something
\end{lemma}

\begin{theorem}
Something
\end{theorem}

\begin{corollary}
Something
\end{corollary}

\begin{theorem}
Something
\end{theorem}

\end{document}


## Final word

Nobody forces you to use the \spnewtheorem command and the predefined environments, but probably copy editors at Springer will be happier if you do. If you use svmono for your personal usage, you shouldn't: the class is not the best you can find, in my opinion. For your own monograph use memoir.

Will this do?

\documentclass{svmono}

\newtheorem{thm}{Theorem}
\newtheorem{lem}[thm]{Lemma}
\newtheorem{cor}[thm]{Corollary}

\begin{document}
\chapter{Title}
\section{Title}

\begin{lem}
Something
\end{lem}

\begin{thm}
Something
\end{thm}

\begin{cor}
Something
\end{cor}

\begin{thm}
Something
\end{thm}

\end{document}