Pick $R\in \CRing$. Put a sheaf of rings on $\spec R$ by [global sections](global sections).

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\begin{tikzcd}
	{\mathcal{O}_{X, p}} && {\mathcal{O}_X} \\
	\\
	{\left\{ p\right\}} && X
	\arrow[hook, from=3-1, to=3-3]
	\arrow[from=1-3, to=3-3]
	\arrow[dashed, from=1-1, to=3-1]
	\arrow[dashed, from=1-1, to=1-3]
	\arrow["\lrcorner"{anchor=center, pos=0.125}, draw=none, from=1-1, to=3-3]
\end{tikzcd}