Lemma hzlthsntoleh ( n m : hz ) : hzlth n ( m + 1 ) -> hzleh n m . Proof. intros a . apply (hzlehandplusrinv n m 1) . apply ( hzlthtolehsn n ( m + 1 ) a ) . Defined.
Require Import UniMath.MoreFoundations.PartA. Require Import UniMath.Algebra.Monoids. Require Import UniMath.Algebra.Groups.