fact: Definition core_z_iso_weq (x y : C) : @z_iso C x y ≃ @z_iso core x y.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.Univalence UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.Groupoids UniMath.CategoryTheory.opp_precat UniMath.CategoryTheory.PrecategoryBinProduct