Math & Science ⇒ Alternative numbering Definitions 1a 1b

[bartvde]

Hi all,

Is there a way to number certain Definitions (or Theorems, Propositions, ...) like this

Definition 4
...
Definition 5a
Definition 6a
...
Definition 5b
Definition 6b
...
Definition 7

Ideally, I want this this special numbering to be automatic: e.g., adjusting the counter of Definition 5b should somehow reference the counter of Definition 5a, and so on.

Thanks

[frabjous]

Of course, but it would help to see a minimal working example of your current usage, so we know what packages, documentclass, etc., you're using.

However, here's an initial suggestion for you, assuming you're using amsthm to create your definition environment.

Code: Select all

\documentclass{article}
\usepackage{amsthm}

\theoremstyle{definition}
\newtheorem{definition}{Definition}
\newtheorem{subdefinition}{Definition}[definition]
\renewcommand{\thesubdefinition}{\thedefinition\alph{subdefinition}}

\begin{document}

\begin{definition} 
   A definition 
\end{definition}

\begin{subdefinition} 
   A subdefinition 
\end{subdefinition}

\begin{subdefinition} 
   Another subdefinition 
\end{subdefinition}

\begin{definition}
    Another definition.
\end{definition}

\end{document}

subdefs.png (8.31 KiB) Viewed 6591 times

[bartvde]

It's hard to give an MWE since I can't do any better than just give the result.

The latex code that you provided is not exactly what I need:
- I want to start directly with "Definition 1a", without using "Definition 1".
- I want to mix everything up. E.g., in the following order: 1, 2a, 3a, 4, 2b, 3b.

This kind of numbering may look bad, since it destroys the logical numbering of the definitions/theorems/..., but in the context of equivalent definitions, I find it useful.