Definition lwhisker_is_cartesian_invertible : lwhisker_is_cartesian f₂. Proof. intros x y h g₁ g₂ γ Hγ. apply (is_cartesian_2cell_invertible β Hβ). apply (pr2 Hf₁). apply (is_cartesian_2cell_invertible _ (is_invertible_2cell_inv Hβ)). exact Hγ. Defined.
Require Import UniMath.Foundations.All. Require Import UniMath.MoreFoundations.All. Require Import UniMath.CategoryTheory.Core.Categories. Require Import UniMath.CategoryTheory.Core.Functors. Require Import UniMath.Bicategories.Core.Bicat. Import Bicat.Notations. Require Import UniMath.Bicategories.Core.Invertible_2cells. Require Import UniMath.Bicategories.Core.Unitors. Require Import UniMath.Bicategories.Core.BicategoryLaws. Require Import UniMath.Bicategories.Core.EquivToAdjequiv. Require Import UniMath.Bicategories.Morphisms.Adjunctions. Require Import UniMath.Bicategories.Morphisms.FullyFaithful. Require Import UniMath.Bicategories.Morphisms.DiscreteMorphisms. Require Import UniMath.Bicategories.Morphisms.InternalStreetFibration. Section InvertibleFromInternalSFib. End InvertibleFromInternalSFib.