\begin{picture}(0,0)%
\includegraphics{myfile.pstex}%
\end{picture}%
\setlength{\unitlength}{3947sp}%
%
\begingroup\makeatletter\ifx\SetFigFont\undefined%
\gdef\SetFigFont#1#2#3#4#5{%
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  \fontfamily{#3}\fontseries{#4}\fontshape{#5}%
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\fi\endgroup%
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