Example 42.7.2. Here $S = \mathop{\mathrm{Spec}}(k)$ and $k$ is a field. We set $\delta (pt) = 0$ where $pt$ indicates the unique point of $S$. The pair $(S, \delta )$ is an example of a situation as in Situation 42.7.1 by Morphisms, Lemma 29.17.5.

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