# \mathversion{sans}

I'd like to be able to switch to sans serif math in some environment,
where I use sans serif text. I decided to use the cmbright fonts font
this purpose. The following example compiles fine :

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage{lmodern}

\DeclareMathVersion{sans}
\SetSymbolFont{operators} {sans}{OT1}{cmbr}{m}{n}
\SetSymbolFont{letters} {sans}{OML}{cmbrm}{m}{it}
\SetSymbolFont{symbols} {sans}{OMS}{cmbrs}{m}{n}

\begin{document}

\mathversion{sans}
$\int_{0}^{+\infty}\sum_{n=1}^{2}\frac{\partial f(x)}{\partial x}=0$

\mathversion{normal}
$\int_{0}^{+\infty}\sum_{n=1}^{2}\frac{\partial f(x)}{\partial x}=0$

\end{document}

However, I would also like to use the fourier fonts (or their fouriernc
variant). But then, I run into a bug, since the = signs (and some other
symbols, I guess) disapears in the sans serif version of the font. The
following example looks terrible :

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage{fourier}

\DeclareMathVersion{sans}
\SetSymbolFont{operators} {sans}{OT1}{cmbr}{m}{n}
\SetSymbolFont{letters} {sans}{OML}{cmbrm}{m}{it}
\SetSymbolFont{symbols} {sans}{OMS}{cmbrs}{m}{n}

\begin{document}

\mathversion{sans}
$\int_{0}^{+\infty}\sum_{n=1}^{2}\frac{\partial f(x)}{\partial x}=0$

\mathversion{normal}
$\int_{0}^{+\infty}\sum_{n=1}^{2}\frac{\partial f(x)}{\partial x}=0$

\end{document}

When designing fourier, Michel Bovani decided to use his own encoding
for math fonts. I guess that this design feature explains the bug. Is
there an easy workaround?

--
Benoît RIVET
.