fact: Definition path_functor_helper A B (F1 F2 : Functor A B) (pf1 pf2 : F1 = F2) : P A -> P B -> pf1 = pf2 := fun PA PB => @path_ishprop _ (@HP A B PA PB F1 F2) _ _.
imports: Category.Core Functor.Core NaturalTransformation.Core Functor.Composition.Core NaturalTransformation.Composition.Core NaturalTransformation.Composition.Laws Functor.Identity Pseudofunctor.Core Cat.Core FunctorCategory.Core FunctorCategory.Morphisms NaturalTransformation.Isomorphisms Category.Morphisms NaturalTransformation.Paths Basics.PathGroupoids Basics.Trunc