proposition: Proposition comp_in_cod_fib {x : C} {gz₁ gz₂ gz₃ : C/x} (φp : gz₁ --> gz₂) (ψq : gz₂ --> gz₃) : dom_mor (φp · ψq) = dom_mor φp · dom_mor ψq.
proof: Proof. cbn ; unfold dom_mor. rewrite transportf_cod_disp. apply idpath. Qed.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Prelude UniMath.CategoryTheory.Adjunctions.Core UniMath.CategoryTheory.Equivalences.Core UniMath.CategoryTheory.Limits.Terminal UniMath.CategoryTheory.Limits.Pullbacks UniMath.CategoryTheory.DisplayedCats.Core UniMath.CategoryTheory.DisplayedCats.Fibrations UniMath.CategoryTheory.DisplayedCats.Fiber UniMath.CategoryTheory.DisplayedCats.Codomain