mathlib3

e4ceee66 - feat(group_theory/order_of_element): Raising to a coprime power is a bijection (#7923)

feat(group_theory/order_of_element): Raising to a coprime power is a bijection (#7923) If `gcd(|G|,k)=1` then the `k`th power map is a bijection Co-authored-by: tb65536 <tb65536@users.noreply.github.com>