fact: Definition pb_1cell_pr1 {p q : pb_cone} (φ : pb_1cell p q) : invertible_2cell (φ · pb_cone_pr1 q) (pb_cone_pr1 p) := pr12 φ.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.Bicategories.Core.Bicat UniMath.Bicategories.Core.Invertible_2cells UniMath.Bicategories.Core.Univalence