fact: Definition weq_cat_eq_cat_equiv (C D : precategory_data) : cat_eq_2 C D ≃ cat_equiv C D.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.whiskering UniMath.CategoryTheory.catiso