End Bigdproduct.
Section MorphIsometry.
Variable gT : finGroupType.
Implicit Types (D G H K : {group gT}) (aT rT : finGroupType).

Lemma cfIsom_iso rT G (R : {group rT}) (f : {morphism G >-> rT}) :
forall isoG : isom G R f, isometry (cfIsom isoG).