mathlib

acd02bbd - feat(algebra/hom/equiv): two little `simp` lemmas for `units.map_equiv` (#16701)

feat(algebra/hom/equiv): two little `simp` lemmas for `units.map_equiv` (#16701) Two lemmas I needed for working with the class group of rings. Co-authored-by: Anne Baanen <Vierkantor@users.noreply.github.com>