Lemma 72.6.6 (0ENN)—The Stacks project

Table of contents
Part 4: Algebraic Spaces
Chapter 72: Algebraic Spaces over Fields
Section 72.6: Weil divisors
Lemma 72.6.6 (cite)

Lemma 72.6.6. Let $S$ be a scheme. Let $X$ be a locally Noetherian integral algebraic space over $S$. Let $f \in R(X)^*$. Then the collections

\[ \{ Z \subset X \mid Z\text{ a prime divisor with generic point }\xi \text{ and }f\text{ not in }\mathcal{O}_{X, \xi }\} \]

and

\[ \{ Z \subset X \mid Z \text{ a prime divisor and }\text{ord}_ Z(f) \not= 0\} \]

are locally finite in $X$.

Proof. There exists a nonempty open subspace $U \subset X$ such that $f$ corresponds to a section of $\Gamma (U, \mathcal{O}_ X^*)$. Hence the prime divisors which can occur in the sets of the lemma all correspond to irreducible components of $|X| \setminus |U|$. Hence Lemma 72.6.1 gives the desired result. $\square$

The Stacks project

Comments (0)

Post a comment