\documentclass{amsart}

\newcommand{\pathtotrunk}{../../}
% \input{\pathtotrunk text/article_preamble.tex}

\pagestyle{empty}

\begin{document}
\thispagestyle{empty}

\begin{align*}
abc bca cab ab bc ca a b c \\
x y z A u_x u_y u_z
\end{align*}
\end{document}