mathlib

a3050f42 - feat(group_theory/order_of_element): Endomorphisms of cyclic groups (#6645)

feat(group_theory/order_of_element): Endomorphisms of cyclic groups (#6645) If G is cyclic then every group homomorphism G -> G is a power map. Co-authored-by: tb65536 <tb65536@users.noreply.github.com>