Example 85.8.2. Let $A$ be a weakly admissible topological ring. In this case we have

$\text{Spf}(A)_{red} = \mathop{\mathrm{Spec}}(A/\mathfrak a)$

where $\mathfrak a \subset A$ is the ideal of topologically nilpotent elements. Namely, $\mathfrak a$ is a radical ideal (Lemma 85.4.10) which is open because $A$ is weakly admissible.

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