Section ZpUnitMorphism.
Variable u : {unit 'Z_#[a]}.
Definition Zp_unitm := aut injm_cyclem im_cyclem.
End ZpUnitMorphism.
Canonical Zp_unit_morphism := Morphism Zp_unitmM.
End CyclicAutomorphism.

Lemma sum_totient_dvd n : \sum_(d < n.+1 | d %| n) totient d = n.