proposition: Lemma rstabs_group_set : group_set rstabs.
proof: Proof. apply/group_setP; rewrite inE group1 repr_mx1 mulmx1. split=> //= x y /setIdP[Gx nUx] /setIdP[Gy]; rewrite inE repr_mxM ?groupM //. by apply: submx_trans; rewrite mulmxA submxMr. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq path) mathcomp(div choice fintype tuple finfun bigop prime) mathcomp(ssralg poly polydiv finset fingroup morphism) mathcomp(perm automorphism quotient finalg action zmodp) mathcomp(commutator cyclic center pgroup matrix mxalgebra) mathcomp(mxpoly)