fact: Definition double_hor_comp {C : category} {D : twosided_disp_cat C C} (Cm : hor_comp_data D) {x y z : C} (h₁ : D x y) (h₂ : D y z) : D x z := pr1 Cm x y z h₁ h₂.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.TwoSidedDisplayedCats.TwoSidedDispCat UniMath.CategoryTheory.TwoSidedDisplayedCats.Isos