13

I just read a book where the equations in the Introduction were numbered slightly differently compared to the other sections, namely by (In.x) where x stands for the number (so it starts off as (In.1), (In.2), (In.3) and so on.

I'd like to try this this but I haven't found out so far how to do this systematically, i.e. not tagging each equation manually but rather using someting like the \label functionality .. any suggestions?

mon
  • 19
harlekin
  • 515

2 Answers2

13

You can do this using 

\renewcommand{\theequation}{ln.\arabic{equation}}

If you want to switch it back, you can use

\renewcommand{\theequation}{\arabic{equation}}

A complete MWE follows.

\documentclass{article}

\renewcommand{\theequation}{ln.\arabic{equation}}
\begin{document}

\begin{equation}
  y=mx+b
\end{equation}
\end{document}
cmhughes
  • 100,947
  • 1
    there must be a duplicate somewhere (I did search)... if someone points it out, I'll delete my answer... – cmhughes Jan 01 '13 at 20:20
3

Another possibility is to load mathtools (an extension of amsmath, so it's needless to load the latter), which allows for defining tag ‘styles’ (named tag forms)and use them with a \usetagform command. The previous code would become:

\documentclass{article}
\usepackage{mathtools}

\newtagform{(L}{(ln})

\begin{document}

\usetagform{L}
\begin{equation}
  y=mx+b
\end{equation}

\end{document}
Bernard
  • 271,350