proposition: Proposition isaset_hor_id {C : category} (D : strict_twosided_disp_cat C C) : isaset (hor_id D).
proof: Proof. use isaset_total2. - use isaset_total2. + use impred_isaset ; intro. apply is_strict_strict_twosided_disp_cat. + intro I. repeat (use impred_isaset ; intro). apply isaset_disp_mor. - intro. apply isasetaprop. apply isaprop_hor_id_laws. Qed.
imports: UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Prelude UniMath.CategoryTheory.Core.Setcategories UniMath.CategoryTheory.Categories.CategoryOfSetCategories UniMath.CategoryTheory.TwoSidedDisplayedCats.TwoSidedDispCat UniMath.CategoryTheory.TwoSidedDisplayedCats.DisplayedFunctor UniMath.CategoryTheory.TwoSidedDisplayedCats.DisplayedNatTrans UniMath.CategoryTheory.TwoSidedDisplayedCats.Isos UniMath.CategoryTheory.TwoSidedDisplayedCats.Univalence UniMath.CategoryTheory.TwoSidedDisplayedCats.Strictness UniMath.CategoryTheory.TwoSidedDisplayedCats.TransportLaws UniMath.Bicategories.DoubleCategories.Basics.DoubleCategoryBasics