fact: Definition RoofTopEq2 {x y : ob C} {R1 R2 : Roof x y} (T : RoofTop R1 R2) : (RoofTopMor1 T) · (RoofMor2 R1) = (RoofTopMor2 T) · (RoofMor2 R2) := dirprod_pr2 (dirprod_pr2 (pr2 T)).
imports: UniMath.Foundations.PartD UniMath.Foundations.Propositions UniMath.Foundations.Sets UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.Functors