proposition: Proposition span_associator_laws : span_laws (identity _) (identity _) (comp_span h₁ (comp_span h₂ h₃)) (comp_span (comp_span h₁ h₂) h₃) span_associator_mor.
proof: Proof. split ; cbn. - rewrite id_right. unfold span_associator_mor. rewrite !assoc. rewrite !PullbackArrow_PullbackPr1. apply idpath. - rewrite id_right. unfold span_associator_mor. rewrite !assoc. rewrite !PullbackArrow_PullbackPr2. apply idpath. Qed.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Prelude UniMath.CategoryTheory.Core.Setcategories UniMath.CategoryTheory.Limits.Pullbacks UniMath.CategoryTheory.DisplayedCats.Core UniMath.CategoryTheory.DisplayedCats.Constructions UniMath.CategoryTheory.DisplayedCats.Isos UniMath.CategoryTheory.DisplayedCats.Univalence UniMath.CategoryTheory.TwoSidedDisplayedCats.TwoSidedDispCat UniMath.CategoryTheory.TwoSidedDisplayedCats.Isos UniMath.CategoryTheory.TwoSidedDisplayedCats.Univalence UniMath.CategoryTheory.TwoSidedDisplayedCats.Total UniMath.CategoryTheory.TwoSidedDisplayedCats.Strictness UniMath.CategoryTheory.TwoSidedDisplayedCats.Examples.Constant UniMath.CategoryTheory.TwoSidedDisplayedCats.Examples.DispCatOnTwoSidedDispCat