fact: Definition left_morphism_of : NaturalTransformation (F' o CF) (DF o F).
imports: Category.Core Functor.Core NaturalTransformation.Core Functor.Identity Functor.Composition.Core NaturalTransformation.Composition.Core NaturalTransformation.Composition.Laws Functor.Dual NaturalTransformation.Dual Adjoint.Core Adjoint.UnitCounit Adjoint.Dual