fact: Definition three_comp {C : category} (xyz : three C) := pr2 (pr222 xyz).
imports: UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Prelude UniMath.CategoryTheory.PrecategoryBinProduct UniMath.CategoryTheory.DisplayedCats.Core UniMath.CategoryTheory.DisplayedCats.Total UniMath.CategoryTheory.Limits.Graphs.Colimits UniMath.CategoryTheory.DisplayedCats.Examples.Arrow