proposition: Lemma of_irrK (phi: 'CF(G)) : {in dirr_constt phi, cancel (@of_irr G) (to_dirr phi)}.
proof: Proof. case=> b i; rewrite dirr_consttE cfdotZr rmorph_sign /= /to_dirr mulr_sign. by rewrite fun_if oppr_gt0; case: b => [|/ltW/le_gtF] ->. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq path) mathcomp(div choice fintype tuple finfun bigop prime order) mathcomp(ssralg poly finset fingroup morphism perm) mathcomp(automorphism quotient finalg action gproduct) mathcomp(zmodp commutator cyclic center pgroup sylow) mathcomp(frobenius vector ssrnum ssrint archimedean intdiv) mathcomp(algC algnum classfun character integral_char)