Section Isometries.
Variables (gT : finGroupType) (L G : {group gT}) (S : seq 'CF(L)).
Implicit Type nu : {additive 'CF(L) -> 'CF(G)}.

Lemma Zisometry_of_iso f :
free S -> {in S, isometry f, to 'Z[irr G]} ->
{tau : {linear 'CF(L) -> 'CF(G)} | {in S, tau =1 f}
& {in 'Z[S], isometry tau, to 'Z[irr G]}}.