Lemma negweqstn0sn (n : nat) : ¬ (stn O ≃ ⟦S n⟧). Proof. unfold neg. assert (lp: ⟦S n⟧) by apply lastelement. intro X. apply weqstn0toempty. apply (pr1 ( invweq X ) lp). Defined.
Require Import UniMath.MoreFoundations.Tactics. Require Import UniMath.MoreFoundations.DecidablePropositions. Require Import UniMath.MoreFoundations.NegativePropositions.