Prenex Implicits cfIsom.
Section InvMorphism.
Variables (aT rT : finGroupType) (G : {group aT}) (f : {morphism G >-> rT}).
Variable R : {group rT}.
Hypothesis isoGR : isom G R f.

Lemma cfIsomKV : cancel (cfIsom (isom_sym isoGR)) (cfIsom isoGR).