Stacks 09MQ (3) theorem

Let $X$, $Y$, $Z$ be schemes, and possibly some arrows, satisfying the following conditions:

• $g*f$ quasi-separated
• $f$ surjective, universally closed

Then

• $g$ quasi-separated

References

• Stacks Project, https://stacks.math.columbia.edu/tag/09MQ (Fabio)