fact: Definition carrier_of_sub_category (C : category) (C' : sub_precategories C) : category := make_category _ (has_homsets_carrier_of_subcategory C C').
imports: UniMath.Foundations.Sets UniMath.MoreFoundations.PartA UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.Isos