Section DerivedGroup.
Variable gT : finGroupType.
Implicit Types G H : {group gT}.

Lemma cfExp_prime_transitive G (i j : Iirr G) :
prime #|G| -> i != 0 -> j != 0 ->
exists2 k, coprime k #['chi_i]%CF & 'chi_j = 'chi_i ^+ k.