proposition: Lemma ltmx_trans m n : transitive (@ltmx F m m n).
proof: Proof. by move=> A B C; move/ltmxW; apply: sub_ltmx_trans. 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)