proposition: Lemma tri_1_GGεη : triangle_1_statement_over_id GGεη.
proof: Proof. intros x xx; cbn. unfold ε_ses_ff_data, η_ses_ff_data. etrans. apply maponpaths_2; use homotweqinvweq. etrans. exact (z_iso_disp_after_inv_mor (pr2 (FF_split _ _))). apply maponpaths_2, homset_property. Qed.
imports: UniMath.Foundations.Sets UniMath.MoreFoundations.PartA UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.Adjunctions.Core UniMath.CategoryTheory.Equivalences.Core UniMath.CategoryTheory.DisplayedCats.Core UniMath.CategoryTheory.DisplayedCats.Functors UniMath.CategoryTheory.DisplayedCats.NaturalTransformations UniMath.CategoryTheory.DisplayedCats.Isos UniMath.CategoryTheory.DisplayedCats.Fiber