Can I use a symbol that has been previously redefined by the \renewcommand?

Question

I have a line \renewcommand{\subset}{\subseteq} in my document. Now, out of all things, I need to use the symbol \subset. Is there any way to do so?

Answer 1

First and foremost: Don’t redefine standard commands like \subset and \alpha. It’s bad style and will lead to confusion when collaborating with others, submitting papers to journals, or using external tools.

But if you absolutely must, you can do the following:

\documentclass{article}

\usepackage{amsmath}

\let\oldsubset=\subset

\renewcommand{\subset}{\subseteq}

\begin{document}

\[
    A \oldsubset B
    \implies
    A \subset B
\]

\end{document}