proposition: Fact det_is_repr : mx_repr G det_repr_mx.
proof: Proof. split=> [|g h Gg Gh]; first by rewrite /det_repr_mx repr_mx1 det1. by rewrite /det_repr_mx repr_mxM // det_mulmx !mulmxE scalar_mxM. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype choice ssrnat seq) mathcomp(path div fintype tuple finfun bigop prime order) mathcomp(ssralg poly finset gproduct fingroup morphism) mathcomp(perm automorphism quotient finalg action zmodp) mathcomp(commutator cyclic center pgroup nilpotent sylow) mathcomp(abelian matrix mxalgebra mxpoly mxrepresentation) mathcomp(vector ssrnum algC classfun archimedean)