How to create a list of symbols where symbols can be used in math mode?

Question

I describe complex protocols with lots of variables in different files. The problem is that I might change the variable names later. My idea was to define variable names as Latex commands like \lengthtree (instead of writing e.g. $\ell_t$). Later I can easily change \lengthtree to $L_t$ by just redefine the latex command.

Now I want to create a list of symbols and I am searching for a possibility to create it automatically. I give the glossaries package a try, but I get Latex errors if I use the symbols in math environments.

What would be the "state-of-the-art" solution to define my variables (which can be used also in math mode) at one global point? A list of symbols should be created automatically.

Answer 1

As barbara mentioned, you can use \ensuremath like this:

\documentclass{article}

\usepackage{glossaries}

\makeglossaries

\newglossaryentry{lengthtree}%
{%
  name={\ensuremath{L_t}},
  description={description here},
  sort={L}
}

\begin{document}

In line: \gls{lengthtree}. In math mode: 
\[
  \gls{lengthtree}
\]

\printglossary[title={List of Symbols}]

\end{document}

The arguments against \ensuremath come down to two main issues (see When not to use \ensuremath for math macro?):

Firstly, you might end up with $ inside the argument of \ensuremath. This won't occur in this example, as the argument of \ensuremath is being explicitly set to L_t.

Secondly, there is an issue of semantics. Following this line of argument, you should define the entry without \ensuremath and do $\gls{lengthtest}$, which is fine in the document text that you type, but this will cause a problem in the glossary where the style doesn't automatically shift to math mode when it comes to the entry name. Personally, I think \ensuremath is okay in this context, but for the purists who can't stand it, here's an alternative solution:

\documentclass{article}

\usepackage{glossaries}

\makeglossaries

\newglossaryentry{lengthtree}%
{%
  name={$L_t$},
  text={L_t},
  description={description here},
  sort={L}
}

\begin{document}

In line: $\gls{lengthtree}$. In math mode: 
\[
  \gls{lengthtree}
\]

\printglossary[title={List of Symbols}]

\end{document}

Both the above examples produce:

Answer 2

I think you mean something like this, that defines the commands and makes a list at the same time.

\documentclass{article}

\newcommand\mysymbol[3]{%
\protected\gdef#1{#2}%
\item[$#2$]#3}

\begin{document}

\section*{List of symbols}

\begin{description}
\mysymbol{\zzz}{z_z^z}{Something about $Zzzzz$.}
\mysymbol{\Txxx}{Tx_{xx}}{The xx component of T.}
\mysymbol{\vvvv}{V_2}{$V$, the second.}
\mysymbol{\vvvvv}{V_3}{$V$, the third.}
\end{description}
\section{zzz}

\[ \zzz=\Txxx\]
where
\[\vvvv=3\]
and
\[\vvvvv=X\]

\end{document}