proposition: Lemma addmI : right_injective +%MM.
proof: Proof. by move=> m ? ?; rewrite ![(m + _)%MM]addmC => /addIm. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(choice fintype tuple finfun bigop finset binomial) mathcomp(order fingroup perm ssralg zmodp poly ssrint) mathcomp(matrix vector) mathcomp(bigenough) ssrcomplements freeg