Can I use \input inside an \include?

Question

I know it is not possible to nest one \include inside another, but what about \input? Is it possible to have something like:

\documentclass{article}

\begin{document}

\include{file1}

\end{document}

and then in file1.tex:

\section{samplesection}
\input{file2}

in file2.tex;

\section{samplesection2}
Hello

Answer 1

Quoting Kopka and Daly, Guide to LaTeX, 4th edition (2004), p. 207:

\include commands may not be nested: They may only appear in the main processing file. However, an \input command may be given within a file that is \included.