proposition: Lemma dirr_constt_oppI (phi: 'CF(G)) : dirr_constt phi :&: dirr_constt (-phi) = set0.
proof: Proof. apply/setP=> i; rewrite inE !dirr_consttE cfdotNl inE. apply/idP=> /andP [L1 L2]; have := ltr_pDl L1 L2. by rewrite subrr lt_def eqxx. 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)