feat(data/zmod/quotient): `orbit (zpowers a) b` is a cycle of order `minimal_period ((•) a) b` (#14124)
feat(data/zmod/quotient): `orbit (zpowers a) b` is a cycle of order `minimal_period ((•) a) b` (#14124)

This PR applies the orbit-stabilizer theorem to the action of a cyclic subgroup.





leanprover-community/mathlib,leanprover-community/mathlib