mathlib

ecec43a2 - feat(algebraic_geometry/open_immersion): Easy results about open immersions. (#10776)

feat(algebraic_geometry/open_immersion): Easy results about open immersions. (#10776) Co-authored-by: Andrew Yang <36414270+erdOne@users.noreply.github.com> Co-authored-by: Johan Commelin <johan@commelin.net>