proposition: 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: Proof. simpl; now rewrite dualelement_2x. Defined.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.Combinatorics.Maybe UniMath.Combinatorics.StandardFiniteSets UniMath.Algebra.Domains_and_Fields UniMath.Algebra.RigsAndRings