# New package -> missing $inserted I don't know how to explain my problem. I have this code \documentclass[a4paper]{article} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} %\usepackage{envmath} \newcommand\irrev{$$\rightarrow \$$} \begin{document} \irrev \end{document}  (a test code) which works but when I add the package envmath I have the following error : ! Missing$ inserted.
<inserted text>
$l.8 \irrev  What's wrong ? Is the package ? How can I use it ? ## 1 Answer As the documentation of the package makes clear, it provides non standard definitions of \( and related commands. You can use $

\documentclass[a4paper]{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{envmath}

\newcommand\irrev{$\rightarrow \$}
\begin{document}

\irrev

\end{document}


Or not use the package, depending on requirements.

• Ok, so there are packages which redefine (. Have I right understand ? (Sorry, i'm not fluent in english, I may have some misunderstandings) – Ccile Dec 18 '16 at 20:16
• @Ccile yes I had never used envmath so to answer your question I looked at its documentation (texdoc envmath) and it states in the very first section on page 1 that it redefines \( and you have to use \$ or \begin{math} to start math mode. – David Carlisle Dec 18 '16 at 20:20
• (I looked at mathenv instead of envmath documentation....) Do you think it could be a good practice to always use \\begin{math} (or displaymath) to avoid this kinf of problem ? – Ccile Dec 18 '16 at 20:27
• @Ccile there are very few packages that would redefine a standard latex command in such an incompatible way. I do not know what that package does or why you need it, but it's not really a general problem but just a problem with this package, not a bug, but rather a well documented and intentional incompatibility. – David Carlisle Dec 18 '16 at 20:31