proposition: Lemma eqm_add2r m n1 n2 : (n1 + m == n2 + m)%MM = (n1 == n2).
proof: Proof. exact: (inj_eq (@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