proposition: Lemma stnsum_last_le {n : nat} (f: ⟦S n⟧ -> nat) : f lastelement ≤ stnsum f.
proof: Proof. intros. rewrite stnsum_step. apply natlehmplusnm. Defined.
imports: UniMath.Foundations.NaturalNumbers UniMath.MoreFoundations.Tactics UniMath.MoreFoundations.DecidablePropositions UniMath.MoreFoundations.NegativePropositions