Lemma lastelement_ge {n : nat} : ∏ i : ⟦S n⟧, @lastelement n ≥ i. Proof. intros. apply natlthsntoleh. unfold lastelement. apply stnlt. Defined.
Require Import UniMath.MoreFoundations.Tactics. Require Import UniMath.MoreFoundations.DecidablePropositions. Require Import UniMath.MoreFoundations.NegativePropositions.