proposition: Lemma stnsum_eq {n : nat} (f g: ⟦n⟧ -> nat) : f ~ g -> stnsum f = stnsum g.
proof: Proof. intros h. induction n as [|n IH]. - apply idpath. - rewrite 2? stnsum_step. induction (h lastelement). apply (maponpaths (λ i, i + f lastelement)). apply IH. intro x. apply h. Defined.
imports: UniMath.Foundations.NaturalNumbers UniMath.MoreFoundations.Tactics UniMath.MoreFoundations.DecidablePropositions UniMath.MoreFoundations.NegativePropositions