mathlib

b0e8ced1 - feat(group_theory/nilpotent): add intermediate lemmas (#9016)

feat(group_theory/nilpotent): add intermediate lemmas (#9016) Add two new lemmas on nilpotent groups. Co-authored-by: ineswright <52750254+ineswright@users.noreply.github.com> Co-authored-by: Johan Commelin <johan@commelin.net>