\documentclass{article}
\input preambula.tex
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\begin{document}
\title{Approximation and regularization}
\author{  (one-variable problem)}
\maketitle
\input{latex_abbr03.tex}
\input{gadget05.tex}
%\newcommand{\tr}{{\rm Tr}\,}

\tableofcontents

\input{123approx.tex}
%\input{150existance.tex}
%\input{151regular.tex}



\end{document}