fact: Variables (rG : mx_representation algC G n1) (rH : mx_representation algC H n2).
imports: HB(structures) mathcomp(all_ssreflect) mathcomp(ssralg fingroup morphism perm gproduct) mathcomp(ssrnum matrix vector mxalgebra algC) mathcomp(classfun character mxrepresentation) tools ordcast partition sorted permcomp cycles cycletype permcent