fact: Definition right_unitor_funclass (ρ' : right_unitor): ∏ x : ob C, I_posttensor x --> x := pr1 (nat_z_iso_to_trans ρ').
imports: UniMath.Foundations.PartD UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.ProductCategory UniMath.CategoryTheory.PrecategoryBinProduct UniMath.CategoryTheory.whiskering