fact: Definition po_precategory_data_is_precategory (PO : po X) : is_precategory (po_precategory_data PO).
imports: UniMath.Foundations.HLevels UniMath.Foundations.Sets UniMath.Foundations.Propositions UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.Univalence