Lemma dualvalue_eq {X : UU} {n : nat} (v : ⟦ n ⟧%stn -> X) (i : ⟦ n ⟧%stn) : (v i) = (λ i' : ⟦ n ⟧%stn, v (dualelement i')) (dualelement i). Proof. simpl; now rewrite dualelement_2x. 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.