proposition: Lemma amulr_inj : injective amulr.
proof: Proof. by move=> u v /lfunP/(_ 1); rewrite !lfunE /= !mul1r. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(choice fintype div tuple finfun bigop ssralg) mathcomp(finalg zmodp matrix vector poly)