comflict between breqn and flexisym

[jszhao]

The following two pieces of code will give errors:

\documentclass{article}
\usepackage[cmbase]{flexisym}
\usepackage{breqn}
\begin{document}
\end{document}

and

\documentclass{article}
\usepackage{breqn}
\usepackage[cmbase]{flexisym}
\begin{document}
\end{document}

The first piece of code worked before the last (I am not very sure about it) update (2020/02/16 0.98h). After remove [cmbase], the second piece of code works.

Any hint?

[josephwright]

breqn requires flexisym so you have to load the latter first.

[jszhao]

breqn requires flexisym so you have to load the latter first.

then the code

\documentclass{article}
\usepackage{flexisym}
\usepackage{breqn}
\begin{document}
\end{document}

give the following error message:

! LaTeX Error: Command \dfrac already defined.
               Or name \end... illegal, see p.192 of the manual.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
 ...

l.228 \newcommand{\dfrac}{\genfrac{}{}{}0}

Any hint? Thanks a lot.

[jszhao]

The above error stems from that mathstyle package is loaded before amsmath package.

In the document of mathsytle package, it said that If you want to use this package with amsmath, it is important mathstyle is loaded after amsmath.

In the above example, amsmath package is required by by breqn package, and mathstyle package is require by flexisym package. However, flexisym package should be load before breqn package, thus, that causes the amsmath package is loaded after mathstyle package.

How to fix it? Thanks a lot.

[jszhao]

well, the solution to this error is to load the amsmath package explicitly before the flexisym package, as following,

\documentclass{standalone}
\usepackage{amsmath}
\usepackage[cmbase]{flexisym}
\usepackage{breqn}
\begin{document}
\end{document}

[wspr]

Thanks for this discussion, I’ve updated the docs to make this more clear.