fact: Definition is_opcartesian_sopfib {e₁ e₂ : E} (f : e₁--> e₂) : UU := ∏ (e₃ : E) (g : e₁ --> e₃) (h : F e₂ --> F e₃) (p : #F g = #F f · h), ∃! (φ : e₂ --> e₃), #F φ = h × f · φ = g.
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