proposition: Lemma stablemxM : stablemx V f -> stablemx V g -> stablemx V (f *m g).
proof: Proof. by move=> f_stab /(submx_trans _)->//; rewrite mulmxA submxMr. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype finfun bigop finset fingroup perm order) mathcomp(div prime binomial ssralg finalg zmodp matrix)