proposition: Proposition isaprop_triangle_law {C : category} {D : twosided_disp_cat C C} {I : hor_id D} {Cm : hor_comp D} (l : double_cat_lunitor I Cm) (r : double_cat_runitor I Cm) (a : double_cat_associator Cm) : isaprop (triangle_law l r a).
proof: Proof. repeat (use impred ; intro). apply isaset_disp_mor. Qed.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.TwoSidedDisplayedCats.TwoSidedDispCat UniMath.CategoryTheory.TwoSidedDisplayedCats.Isos