%% 
%%  Example 07-01-4 
%%  Copyright (C) 2016 Herbert Voss
%% 
%% ==== 
% Show page(s) 1
%% 
%% 
\documentclass[]{screxa}
\pagestyle{empty}
\setlength\textwidth{158.31393pt}
\setlength\parindent{0pt}
%StartShownPreambleCommands
\usepackage{amsmath}
\newcommand*\diff{\mathop{}\!\mathrm{d}}
\newcommand*\dst{\,\frac{\diff s}{\diff t}}
%StopShownPreambleCommands
\begin{document}
\begin{align*}
F(x) &= \int\!f(x)\diff x\\
v(t) &= \dst\\
a(t) &= \frac{\diff{}^2s}{\diff t^2}
\end{align*}
\end{document}
