proposition: Lemma rstabs_submod m (W : 'M_(m, \rank U)) : rstabs rU W = rstabs rG (val_submod W).
proof: Proof. apply/setP=> x /[!inE]; apply: andb_id2l => Gx. by rewrite -val_submodS val_submodJ. 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)