proposition: Lemma firstelement_le {n : nat} : ∏ i : ⟦S n⟧, @firstelement n ≤ i.
proof: Proof. intros. apply idpath. Defined.
imports: UniMath.Foundations.NaturalNumbers UniMath.MoreFoundations.Tactics UniMath.MoreFoundations.DecidablePropositions UniMath.MoreFoundations.NegativePropositions