Lemma stn_eq_2 {k : nat} (i: stn k) (j : nat) (eq : pr1 i = j) (P : j < k) : i = (j,, P). Proof. intros; apply stn_eq, eq. Defined.
Require Import UniMath.Foundations.All. Require Import UniMath.MoreFoundations.All. Require Import UniMath.Combinatorics.Maybe. Require Import UniMath.Combinatorics.StandardFiniteSets. Require Import UniMath.Algebra.Domains_and_Fields. Require Import UniMath.Algebra.RigsAndRings.