fact: Definition mor_of_street_fib_base {B₁ B₂ E₁ E₂ : category} {P₁ : E₁ ⟶ B₁} {P₂ : E₂ ⟶ B₂} (F : mor_of_street_fib P₁ P₂) : B₁ ⟶ B₂ := pr1 F.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.Univalence UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.DisplayedCats.Core UniMath.CategoryTheory.DisplayedCats.Total UniMath.CategoryTheory.DisplayedCats.Fibrations