fact: Definition functor_on_fully_faithful_inv_hom {C₁ C₂ : category} (F : C₁ ⟶ C₂) (HF : fully_faithful F) {x y : C₁} (f : F x --> F y) : #F (fully_faithful_inv_hom HF x y f) = f.
imports: UniMath.Foundations.PartD UniMath.Foundations.Propositions UniMath.Foundations.Sets UniMath.MoreFoundations.PartA UniMath.MoreFoundations.Univalence UniMath.MoreFoundations.Tactics UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.TransportMorphisms UniMath.CategoryTheory.Core.Univalence