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

Lemma im_Zp_unitm : Zp_unitm @* units_Zp #[a] = Aut <[a]>.