# ntheorem subhypotheses

I'm trying to create:

 Hypothesis 1a
Hypothesis 1b
Hypothesis 2a
Hypothesis 2b
Hypothesis 3


I followed the code from an earlier thread, but instead of getting "Hypothesis 3", I get "Hypothesis 2c".

What should I do to get "Hypothesis 3"? Thanks so much for all your help.

\documentclass{article}
\usepackage{ntheorem}
\theoremindent1\parindent
\theoremseparator{:}
\newtheorem{theorem}{Hypothesis}
\usepackage{chngcntr}
\newcounter{pretheorem}
\counterwithin{theorem}{pretheorem}
\renewcommand\thetheorem{\arabic{pretheorem}\alph{theorem}}
\newcommand{\theoremgroup}{\refstepcounter{pretheorem}}
\begin{document}
\theoremgroup
\begin{theorem}
This is Hypothesis 1a
\end{theorem}

\begin{theorem}
This is Hypothesis 1b
\end{theorem}
\theoremgroup
\begin{theorem}
This is Hypothesis 2a
\end{theorem}
\begin{theorem}
This is Hypothesis 2b
\end{theorem}
\theoremgroup
\begin{theorem}
This is Hypothesis 3, but I'm getting Hypothesis 2c
\end{theorem}
\end{document}

• Welcome to TeX.SX! I get 3a and not 2c. Nov 23 '17 at 16:51

You can adapt the code for subequations from amsmath. Since this is independent from ntheorem, I omit that part from the example; you can add the setting for the theorem.

\documentclass{article}

\newtheorem{hypothesis}{Hypothesis}

\makeatletter
\newcounter{parenthypothesis}
\newenvironment{subhypothesis}
{
\refstepcounter{hypothesis}%
\protected@edef\theparenthypothesis{\thehypothesis}%
\setcounter{parenthypothesis}{\value{hypothesis}}%
\setcounter{hypothesis}{0}%
\def\thehypothesis{\theparenthypothesis\alph{hypothesis}}%
\ignorespaces
}{%
\setcounter{hypothesis}{\value{parenthypothesis}}%
\ignorespacesafterend
}
\makeatother

\begin{document}

\begin{subhypothesis}
\begin{hypothesis}
This is Hypothesis 1a
\end{hypothesis}

\begin{hypothesis}
This is Hypothesis 1b
\end{hypothesis}
\end{subhypothesis}

\begin{subhypothesis}
\begin{hypothesis}
This is Hypothesis 2a
\end{hypothesis}
\begin{hypothesis}
This is Hypothesis 2b
\end{hypothesis}
\end{subhypothesis}

\begin{hypothesis}
This is Hypothesis 3
\end{hypothesis}

\end{document}


The code you've provided generates the number "3a" for the final hypothesis. If you want it to be numbered "3", i.e., without any suffix, you need to replace the final \theoremgroup directive with

\counterwithout{theorem}{pretheorem}