proposition: Lemma section_of_functor_sig' : section_of_functor_sig <~> SectionOfFunctor.
proof: Proof. issig. Defined.
imports: Functor.Core NaturalTransformation.Core Category.Strict Functor.Identity NaturalTransformation.Identity NaturalTransformation.Paths NaturalTransformation.Composition.Core Functor.Paths HoTT.Basics HoTT.Types