fact: Definition cell_E₁_to_E₂ {x y : E₁} {f g : x --> y} : f ==> g → mor_E₁_to_E₂ f ==> mor_E₁_to_E₂ g := λ α, (pr11 α ,, (pr21 α ,, pr2 α)).
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.PrecategoryBinProduct UniMath.CategoryTheory.DisplayedCats.Core UniMath.CategoryTheory.DisplayedCats.Constructions UniMath.Bicategories.Core.Bicat UniMath.Bicategories.DisplayedBicats.DispBicat UniMath.Bicategories.Core.EquivToAdjequiv UniMath.Bicategories.Core.AdjointUnique UniMath.Bicategories.DisplayedBicats.DispInvertibles UniMath.Bicategories.DisplayedBicats.DispAdjunctions UniMath.Bicategories.DisplayedBicats.DispUnivalence