proposition: Lemma inj_mesym1 : injective mesym1.
proof: Proof. move=> h1 h2 /mnmP eqh; apply/setP=> /= i. by have := eqh i; rewrite !mnmE; do! case: (_ \in _). 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