fact: Definition is_z_iso_core {x y : core} (f : x --> y) : is_z_isomorphism f.
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