proposition: Lemma ϕo_determined : ∏ f, ϕ∙ i f = ϕ∙ i' f.
proof: Proof. intro f. do 2 rewrite ϕo_ϕ₁_ϕ₂. rewrite ϕ₂_determined. rewrite H. apply idpath. Qed.
imports: UniMath.Folds.UnicodeNotations UniMath.Foundations.PartD UniMath.Foundations.Propositions UniMath.Foundations.Sets UniMath.Foundations.UnivalenceAxiom UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.Folds.folds_precat UniMath.Folds.from_precats_to_folds_and_back