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\newenvironment{exercise}{\addtocounter{exercise}{1} \noindent{\bf{Exercise \theexercise.}}}{\vspace{.5cm}}

\newcommand{\p}{\mathcal{P}}
\renewcommand{\empty}{\varnothing}

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\begin{document}


\noindent{\Large{\textsc{Complex Variables \hfill Pledged: Your Name  \\ Spring 2020 \hfill Assignment $n$ }}}

\large

\vspace{1cm}

\begin{exercise}
Construct something from nothing.
\end{exercise}

\begin{proof}[Solution.]
The power set of the empty set,
\[
\p(\empty) = \{ \empty \},
\]
works.
\end{proof}


\end{document}
