Lemma 70.5.11. Notation and assumptions as in Situation 70.5.5. If $X$ is a scheme, then there exists an $i$ such that $X_ i$ is a scheme.
Proof. Choose a finite affine open covering $X = \bigcup W_ j$. By Lemma 70.5.7 we can find an $i \in I$ and open subspaces $W_{j, i} \subset X_ i$ whose base change to $X$ is $W_ j \to X$. By Lemma 70.5.10 we may assume that each $W_{j, i}$ is an affine scheme. This means that $X_ i$ is a scheme (see for example Properties of Spaces, Section 66.13). $\square$
Comments (0)