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 Zp_unit_isom : isom (units_Zp #[a]) (Aut <[a]>) Zp_unitm.