proposition: Fact mx_subseries_module V i : mx_subseries V -> mxmodule rG V`_i.
proof: Proof. move=> modV; have [|leVi] := ltnP i (size V); first exact: all_nthP. by rewrite nth_default ?mxmodule0. 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)