proposition: Lemma eqm_add2l m n1 n2 : (m + n1 == m + n2)%MM = (n1 == n2).
proof: Proof. exact/inj_eq/addmI. 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