Definition stn_left'' {m n : nat} : m < n -> ⟦m⟧ -> ⟦n⟧. Proof. intros le i. exact (make_stn _ _ (istransnatlth _ _ _ (stnlt i) le)). Defined.
Require Import UniMath.MoreFoundations.Tactics. Require Import UniMath.MoreFoundations.DecidablePropositions. Require Import UniMath.MoreFoundations.NegativePropositions.