fact: Definition id_mor_preserves_opcartesian {B : bicat} {e b : B} (p : e --> b) : mor_preserves_opcartesian p p (id₁ e).
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.Bicategories.Core.Bicat UniMath.Bicategories.Core.Invertible_2cells UniMath.Bicategories.Core.Examples.OpCellBicat UniMath.Bicategories.Core.Univalence UniMath.Bicategories.Core.UnivalenceOp UniMath.Bicategories.Morphisms.InternalStreetFibration