When compiling this document:
\documentclass{scrartcl}
\usepackage[biolinum]{libertine}
\usepackage[euler-digits,small]{eulervm}
\begin{document}
\[
U=-\dot\Phi=-\frac d{dx}\int_A B\;dA
\]
\end{document}
I get the error:
! Undefined control sequence.
l.10 U=-\dot
\Phi=-\frac d{dx}\int_A B\;dA
Why is \dot undefined?